Q: Why do we need to take integrity seriously in the vehicle environment?
Chris Rizos, Professor, Geodesy and Navigation, University of New South Wales
A: Since the 1980s, surveyors and geodesists have used GPS for high-accuracy positioning. We take for granted centimeter- and even millimeter-level accuracy positioning capability that is faster, more reliable, at a lower cost and with fewer constraints than ever before. However, the demand for “trustworthy positioning” dismisses such achievements, and the mantra is more “availability” and greater “integrity” to support highly automated driving. Our positioning and navigation community must rise to this challenge.
Rod Bryant, Senior Director, Technology, Positioning, u-blox
A: In autonomous vehicles, a GNSS/inertial module will be just one of several sensors used for location. The risk of contributing to accidents and serious injury will be decomposed and allocated between subsystems by the OEM or system designer. Taking aviation as a model, the allocation to GNSS may be in the form of an alarm limit of a few meters with integrity risk less than 10-6/hour. However, multipath and obstructed sky make automotive risk far more difficult than aviation. Carrier-phase techniques will come into play and new approaches to protection limit estimation will be needed.
Sam Pullen, Senior Research Engineer, Stanford University; Consultant, Sam Pullen Consulting
A: Advanced sensor fusion techniques now make it possible to achieve very accurate PVT results by combining multiple dissimilar sensors. Once we rely on these capabilities for autonomous driving, the primary threat to safety will come from confluences of rare events that were not observed or foreseen during system development. Design for integrity focuses attention on the identification and mitigation of potentially hazardous anomalies before they happen, not afterward.
The first year I was at the Association for Unmanned Vehicle Systems International (AUVSI) convention in 2012 (well before it became Xponential) in Las Vegas, Nevada, I spent a lot of time looking for any exhibitors who were thinking of business in commercial unmanned aerial systems (UAS).
At that time, the U.S. military had not yet suffered the major budget cuts that were to shortly impact extensive military development and use of UAS. So, asking around UAS developers at the AUVSI conference as to when they might think of applying their systems to commercial applications, and the potential changes that integration in the U.S. National Airspace System (NAS) might require … Well, there wasn’t much interest.
I often heard the response that the Federal Aviation Administration (FAA) was so far away from allowing commercial UAS operations in the U.S. that it just wasn’t worth even considering what would be required.
In the years that followed, it has been somewhat refreshing to see the tone and shape of the annual AUVSI convention shift towards the commercial world. And with U.S. Federal Aviation Administration (FAA) regulations now in place for sUAS, and with continuing growth in commercial and developmental operations, it’s clear that a good part of the industry is looking toward the civilian market. Not to say that military UAS development is lagging far behind, but it now seems that we have the prospect of a somewhat more balanced civilian/military marketplace for UAS.
Now, we not only have regularized commercial operations under FAA regulations, we are also hearing more often that Beyond Visual Line of Sight (BVLOS) UAS applications are being developed and modes of operation are being established.
ADS-B (automatic dependent surveillance – broadcast) now appears to be one of one of the prevalent systems that BVLOS applications depend on, since the FAA is implementing ADS-B throughout the U.S., and it’s recognized as a likely component of increased-range UAS operations.
Avionics for Drones
uAvionix in California focuses on equipment aircraft, offering transponders and sensors for integration into UAS and for manned aricraft. Their latest ADS-B offering is a small, lightweight, low-power transponder for unmanned aircraft. Power consumption is low enough to be powered by battery pack for 2 hours, yet is powerful enough to provide visibility to other aircraft and UAVs up to 200 miles away, and uAvionix recently achieved U.S. Federal Communications Commission (FCC) approval for this unit. The ping200S is designed to meet the requirements of TSO-C199 as a Class A Traffic Awareness Beacon System (TABS).
When integrated with a suitable ADS-B GNSS receiver, such as the uAvionix pingNAV GNSS sensor, a UAS would become compatible with the ADS-B system — a significant step towards BVLOS operations. An ADS-B-equipped aircraft can detect and locate other aircraft and warn them of its precise position. The FAA has mandated that all aircraft operating in the NAS be ADS-B equipped by 2020.
Ping200S ADS-B transponder. Logo: uAvionix
PingNav ADS-B OUT GNSS navigation unit. Logo: uAvionix
PingNav is a small, light and low-cost ADS-B OUT compliant navigation source that supports GPS/QZSS, GLONASS, Galileo and Satellite Based Augmentation Systems (SBAS) and has a battery backup for quicker position initialization. The unit also has dual static ports for pressure altimeter readings and includes integrated security and integrity technologies, including Receiver Autonomous Integrity Monitoring (RAIM).
U.S. Department of Transportation Report
Meanwhile, the U.S. Department of Transportation (DoT) recently issued its final “Beyond Traffic 2045” report. The report discusses anticipated air, rail and road transportation challenges in the coming years.
UAS issues mentioned included drone delivery, noting that Google, Amazon and DHL have been evaluating use of unmanned aircraft for several years. Remotely piloted drone deliveries may shortly provide high value and/or urgent cargo to hard-to-reach locations; delivery of medical supplies in remote areas following a natural disaster has already been demonstrated.
Nevertheless, deliveries by drone in highly populated areas will require higher levels of security and safety and will have to overcome privacy risks, so it will likely take longer to verify these capabilities.
Anti-Drone Systems Forecast
Forecasts for growth of the drone market are already reaching heady proportions — one forecast expects sales to reach US$127 billion by 2020! But now the global anti-drone market is being forecast to reach US$1.14 billion by 2022. Maybe having lots of anti-drone systems preventing drone operations could slow down the growth of drone business itself?
Drones in the wrong hands are seen as a possible threat to our security systems, so detection and disabling drones is now becoming a requirement to support those security systems. Growth of the anti-drone market is being driven by more frequent security breaches by unidentified drones and by the use of drones for terrorist activities.
Fuel-Cell Power Drone
EnergyOr Technologies in Montreal, Canada, has been successful in developing and fielding compact fuel-cell products targeted at the growing drone market. Its EPOD fuel cell is the source of power for its H2QUAD 1000 drone, selected by French Air Force’s Centre d’ Expertise Aérienne Militaire (CEAM) for development testing under a Joint Development Agreement (JDA). The JDA is aimed at advanced development of long-endurance UAVs powered by EnergyOr’s fuel-cell system technology.
But what do you do when your fuel-cell-powered drone runs out of juice? For battery-powered drones, it’s easy to take them home and plug them in to recharge them, but their useful range and endurance is somewhat limited. So EnergyOr came up with a recharging system for its fuel cells — just hook up your tired drone to a portable hydrogen recharging set-up and you’re good to go again.
EnergyOr’s H2QUAD 1000 is a fuel cell powered quadrotor UAV capable of carrying a 1 kg payload for more than two hours, which is around four times longer than battery-powered UAVs. The turn-key solution includes a Ground Control Station (GCS), gimbaled 4K camera, portable hydrogen filling station and data acquisition/diagnostic system, as well as onsite operator training and engineering support.
Military Swarms?
Lastly, it appears that the U.S. military is taking on the challenge of using swarms of low-cost semi-autonomous UAVs for reconnaissance. During a full-scale test in October 2016, a swarm of 103 UAVs were deployed from three F/A‐18 Super Hornets over China Lake, California.
The “Perdix” (Greek mythology character who was turned into a partridge) swarm UAV was originally developed by MIT. It has two sets of wings with a 3D printed plastic body, a small rear-mounted propeller, is battery powered and carries a small camera. Perdix software has been refined considerably and is now sixth generation and has external update capability.
More than 670 have been flown, and the Department of Defense plans soon to produce them in batches of 1,000 — which might be a good thing, since they only have an endurance of around 20 minutes. Deploying drones from a fast jet can be a problem, but Perdix is now able to withstand the buffeting and turbulence from release speeds of Mach 0.6 and temperatures of -10° C.
After release, the swarm drones communicate with each other and perform formation flying exercises similar to a surveillance mission. But the swarm doesn’t precisely know how it will undertake a given task before it’s released — so each drone communicates and works with other drones, without a specific leader, and can readily adapt to drones joining or leaving the team.
To sum up, BVLOS advances using commercially available ADS-D avionics for drones, DoT planning for anticipated integration into U.S. national airspace (albeit warning that it may take more than anticipated for Amazon and others to eventually make deliveries using UAVs), growth in anti-drone systems keeping in step with the explosion in the market for drones, hydrogen fuel-cell powered drones, and military drone-swarms for surveillance. There is a lot going on in the developing UAV/UAS market sector.
We have a finite number of pages to bring you each month, one might say a tightly controlled number. That number has never easily accommodated the quantity of fresh, relevant GNSS and PNT news and technical material that emerges each month. The pace of your developments is too fast with which to keep up!
2017 GPS World Receiver Survey (PDF).
This month, a case in point. Most importantly, driving the whole issue is the latest, greatest version of that long-running industry resource and guide, the GNSS Receiver Survey: 24 data-packed pages of it!
There is a major GNSS milestone to report, one which I have personally awaited since the year 2000 — and I know many others have also. When I signed on at this publication, my first assignment was getting its little sister magazine out the door: the summer 2000 issue of Galileo’s World. For four years we published that optimistic quarterly. There was plenty of content for it, but the constellation itself, and the market to support it, were slower in developing. No longer. With the Declaration of Initial Services, reported in the System of Systems section, Galileo is truly and fully open for business.
This month, we also report a momentous satnav development that is not GNSS in the traditional sense, but does come from a globally orbiting constellation. Adding signals from ranging satellites in low-Earth orbit to those from GNSS satellites in medium-Earth orbit provides just the kind of augmentation and backup that many applications critically need. The advantages come primarily in the timing realm, but there is potential for significant positioning benefits, especially once you many innovators out there get your hands on it and combine it with inertial. A true PNT powerhouse.
I haven’t even gotten to this month’s cover story yet: a technical advance in multipath mitigation that has the potential to amp the power, so to speak, of GNSS receivers in many applications. Correlator beamforming is an intriguing new development. Scientists at the Air Force Institute of Technology put it through its paces, and report good results.
At the risk of giving short shrift to any of these essential stories, not to mention the multiple new products, partnerships, application advances and technology updates that appear in smaller bites, we have opted not to omit any, but to cram them all into the one knowledge-laden issue.
We may not be the New York Times, nor can we approach that venerable publication’s mission, reproduced here. But we have our own — All the News That Fits!
Letter to the Editor
My November column began with Jimi Hendrix, drifted into GPS jamming, touched on a mock presidential plebiscite conducted during ION GNSS+, and concluded by reverting to Hendrix’s Purple Haze: “The real [election] results may already be known by the time you read this … Is it tomorrow, or just the end of time?”
Brian in Oklahoma sent me a four-word email in response. “The end of time,” he wrote.
The January reader poll asks you to answer the question: “What are the most important factors to consider in selecting a GNSS vendor?” Answer the poll by Jan. 25 for entry to a drawing for a $50 gift card.
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Welcome to the geointelligence side of the Defense PNT and Geointelligence e-newsletter, a publication combining the staff, readership and subject matter of both its parents. We’ll alternate the two topic areas in this Insights column, while continuing to bring you news stories in every issue relevant to defense hardware, GPS/GNSS and PNT, and to the software and mapping side of the industry — geographic information systems (GIS) applied in defense, first responder and other government fields. That’s the geointelligence side, and I’m privileged this month to bring you the first column under that topic.
I’m Art Kalinski, GPS World’s and Geospatial Solutions’ contributing editor for Geointelligence. A career U.S. Navy officer, I established the Navy’s first GIS in the mid-1980s. I pioneered the use of oblique imagery for public safety and participated in numerous disaster-response actions including GIS/imagery support of the National Guard during Hurricane Katrina. I’ve worked for several companies in the imagery and mapping field.
Next month we’ll focus on a defense hardware GNSS topic. Now here I go on mine: how geography and mapping can correct the misperceptions of history and current public knowledge, and how GIS can support can be used in many areas including government policy and planning.
One authoritative, properly documented map can expose and possibly correct widespread public misinformation about America, its culture and its role in history. For instance, most entering college students think America invented slavery and that the U.S. was a dominant center of slavery.
Slavery can be considered a stain on our country’s history, but I believe this nation’s role in stopping it should also be a source of pride.
I was shocked, although I probably should have known better, by numerous citizen-in-the-street interviews (Watters’ World, Jimmy Kimmel, etc.) showing remarkably detailed knowledge people have about popular culture such as “Dancing with the Stars” or singers and movie stars who will have absolutely no effect on the lives of those being interviewed. However, those same people seem oblivious to science, finance and politics that could have a significant impact on their lives. Some of this appalling lack of knowledge derives from a lack of familiarity with history and in particular with geography.
One study, by Professor Duke Pesta of the University of Wisconsin, left me shaking my head. He found in his 11-year study that “Most entering college students think America invented slavery and that the U.S. was a dominant center of slavery.” Of course, Moses, the victims of the Romans, Genghis Khan, Alexander the Great, Vikings, not to mention Hitler, Stalin, Pol Pot, etc. would differ. Even at its height, the U.S. had less than 4 percent of the world slave population.
Here is a graphic depiction showing the volume and geography of the slave trade, 1600-1900. This is from an article by Harvard Professor Henry Louis Gates, Jr., host of the PBS series “Finding Your Roots” and author of numerous papers about slavery and ancestry. The map and the data driving it originated with The Trans-Atlantic Slave Trade Database, and both are the products of an international research and collaboration endeavor.
The project team worked with at least sixteen different data sets compiled by scholars working since the 1960s to collect archival data on slave-trading voyages from unpublished sources and to code them into a machine-readable format. The team developed sophisticated search interfaces for three different kinds of data, as well as estimates of the size and direction of the trade. Its web site provides a range of ancillary material for educators, including lesson plans and maps, and provides an opportunity for researchers everywhere to continue to contribute their discoveries.
Refer again to the map. It is truly a powerful document.
My History
Lest you think that I’m a disconnected observer of slavery let me share a little family history. I learned about slavery first-hand at my grandmother’s and uncle’s knee. They were both slaves.
In the early twenties, my grandparents immigrated to the U.S. They worked hard, saved their money, had two boys born in Chicago and then moved back to Poland, buying a farm and sawmill with their life savings. In 1938, on his 18th birthday, my father chose to move back to the “New Country” so as not to lose his U.S. citizenship. That was a lucky move, since in 1939 when Hitler invaded Poland from the West, Stalin seized the opportunity and invaded Poland from the East. Stalin, like Putin today, wanted the very fertile farmland that was a lacking in Russia.
(If you read my review of the geopolitical book The Accidental Superpower by Peter Zeihan, although large, Russia lacks adequate prime farmland and always coveted the very fertile region which is now Ukraine.)
When Russian troops invaded, my grandfather was executed in his own front yard and my grandmother and uncle were given 15 minutes to pack their belongings and board cattle cars for Siberia. As part of Stalin’s massive land grab, 1.7 million Poles and Ukrainians were deported in sub-zero freezing weather to work as slave labor in concentration camps.
Map from http://kresy-siberia.org
The speed of the invasion and deportations was so fast and unexpected that it was very disorienting. With dead bodies everywhere and only 15 minutes to gather possessions, many residents were in shock and not thinking clearly. One example: A woman who packed opera gloves and glasses. My grandmother understood the geography she would face and had the good sense to pack warm clothing and a large down comforter, a decision that saved her and my uncle.
Of the 1.7 million deported to the gulags, 100,000 died on the unheated train trips alone. Countless others died in the slave camps of Siberia, with less than 500,000 ultimately surviving. When the Russians, Brits and Americans became allies in 1942, my uncle was able to join the British Army and ultimately fought at Monte Casino and the Italian Campaigns. This photo shows the surviving members of his 60-man unit — my uncle, center front row.
I wish I had been old enough to learn and understand all the details of their ordeal, but much of it wasn’t fit for young ears. I did gain a visceral appreciation of the horrors of war, and slavery in particular.
The U.S. Civil War
Northeast Alabama, Huntsville and Lake Guntersville in particular, is where my wife and I chose to retire. Perfect balance of weather, scenery, quality of life and, most important, the people. We’ve made many good friends here, and a few can still tie themselves to direct descendants of the Civil War. Many, including my wife, still feel pride in the bravery their family members exhibited, just as I feel pride for the World War II military service of my U.S. Navy dad and three uncles.
According to historians, the South almost won the war had it not been for geography and the superior industrial base of the North. Additionally, those of you that have been in combat know that loyalty and personal bravery are seen at the unit level, and both American sides fought fiercely and bravely. Nationalism, philosophy and major political decisions are made at pay grades well above the unit level and are not in the forefront of a soldier’s mind during battle.
Map from http://lincolnmullen.com
There are some that claim that the Civil War was about states’ rights and not slavery. Ask John Brown and other abolitionists. Let’s be honest — the elephant in the states’ rights room was slavery. It pitted brother against brother. Even Ulysses S. Grant and Robert E. Lee were both classmates at West Point. Although on different sides, it took both sides to have the war, the bloodiest in our history. However, what both Union and Confederate troops created was an undeniable truth of American history and American exceptionalism.
To the best of my knowledge, this is the only country in the history of the world that fought a war with itself to free its own slaves.
Other countries have been conquered and slaves freed; in some, slaves revolted and freed themselves while other countries freed their slaves after seeing what the U.S. went through. But no other example matches the U.S. Civil War.
One benefit of having served as a career naval officer is that it exposed me to many parts of the world — Europe, Middle East, Asia, Africa, Latin America, the Caribbean — and not just tourist destinations. The United States still isn’t perfect, but in all my travels around the world, one observation is dominant about life on this geoid.
Whether you or your ancestors came here across the Bering Land Bridge, on the Mayflower, in the hold of a slave ship, through Ellis Island or on a 747, chances are pretty good that your life here is much much better than it would have been had your ancestors stayed where they were.
So, “Johnny,” America didn’t invent slavery, it wasn’t even the major slavery player. But we sure did put a stake in the ground to stop it, and we’ve been freeing people around the world ever since. Instead of pointing to our slave history with shame, we should instead point to the 500,000 casualties that started the path toward freedom. Are life and attitudes in the U.S. perfect? Absolutely not, but look at what we stopped, and look at what we are perfecting.
The surveyor has been known throughout history for many things: part expert measurer, part historian, part lawyer and part geographer. These attributes have led the surveyor to become a trusted member of the mapping community, on both the public, and private sides.
Through the use of technology and associated mapping knowledge, the surveyor has provided the base layer for almost all physical ties of modern-day mapping commonly known as geolocation.
The term has become a common word in today’s lexicon and is defined as follows:
The physical location of an object in the world, which may be described by degrees of longitude and latitude or by a more identifiable place such as city or residence.
Modern GPS receivers have allowed the surveyor to establish positions of important land and governmental monuments throughout the world. However, as technology has moved forward and introduced faster and cheaper ways to utilize GPS measurements with many electronic devices, applications for its use has expanded greatly as well.
Recent uses of technology and the lower cost of entry into the geolocation world, however, is forcing governmental agencies to review uses of this data and potentially restrict its use due to privacy concerns. Let’s first review how we got here:
Maps: Windows on the world
Mapping has been part of civilization since the beginning of time. Early man marked out his discoveries and territorial limits on cave walls and flat rock surfaces. The invention of papyrus in the mid-2500 B.C. by the early Egyptians revolutionized how mapping data was created and retained. Keeping track of what lands had explored and being able to pass along this information provided the early incentive for map makers but crude depictions soon gave way to scientists and historians developing methods to accurately create the world around them.
Introduction of cartography
The art and science of mapmaking started as early as the Babylonian era, producing the first versions depicting a flat earth. The biggest revolutionary strides were by Greek philosophers Aristotle and Ptolemy several centuries later with the introduction to depicting the Earth as round and not flat per previous beliefs. With larger expeditions headed off into oceans and on to foreign lands to seek out new worlds, cartography became more important not in just recording history but accurately depicting the world around us for future exploration.
By the 15th century, hand-drawn maps were being slowly replaced by printing procedures using wooden blocks to ease duplication. It was also during this time that new versions of the Earth were being created to present it as truly spherical and depict the “New World” findings of Columbus and fellow explorers.
The next big enhancement to world mapping occurred in the mid-16th century when a cartographer named Gerardus Mercator of Belgium determined that our spherical Earth could be mapped by using a cylindrical projection to establish accurate latitude and longitude lines on a flat map. His projection method is still used today and is the basis of many more enhancements to world measurement systems made well into the 17th, 18th and 19th centuries in conjunction with extensive exploration and thorough record keeping.
Modern mapping and the geographical information system
The 20th century introduced the scientific world to several major inventions, with the electronic computer among the biggest ones. During the 1960s, Canada was leading the way with the development of a layer-based geographical information system (GIS), with the U.S. Census Bureau following closely behind.
This race to establish GIS dominance led to significant enhancements in mapmaking capability; more specifically, the ability to collect and display large amounts of data in a graphical form. By combining existing tax mapping with aerial photography, utility information and a state-plane coordinate system, local GIS databases began to appear but at a significant cost and effort to both the government agency and parties that wanted to use the information.
Harvard Laboratory Computer Graphics is credited with the creation of vector-based computer graphic in the mid-1970s that allowed the visualization of GIS data through electronic means. The late 1970s/early 1980s also introduced the personal and small computer systems and allowed many more opportunities to begin working with GIS databases.
Esri opens for business
We were also introduced to a little company that started in 1969 in California as a land-use consulting firm, which would end up dominating the GIS software world: Esri. Jack and Laura Dangermond founded the company to better organize geographic and development data for future planning. Little did they know that Esri would eventually become the GIS juggernaut it is today.
By the late 1990s, computer companies with large resources began to see the possibilities of large-scale databases of geographical information along with high-resolution aerial and satellite photography. Microsoft was the first one to offer an online service when it combined current and historical U.S. Geological Survey orthorectified photography to create Terraserver, with more than 2 terabytes of georeferenced data, in 1997.
This was closely followed a small group named Keyhole, which utilized the original Terraserver data as its framework. As this company expanded and the service grew, an upstart search engine firm called Google bought the company and turned the entire site into the early version of Google Earth. The rest is history.
Surveyor’s role in geolcoation
The late 1990s also brought significant enhancements to real-time kinematic (RTK) equipment for the surveyor and the ability to easily produce data within a variety of coordinate systems for use in GIS. (See my earlier column for additional information.) It is also through the survey world that an incredible network of existing static monuments and continuous operating reference stations (CORS) exist to allow the high-accuracy measurement of the precise location of any type of dataset.
Many of these monuments were installed in historical or remote places that were deemed “safe” from being destroyed by future improvements or developments. It is this marriage of high-accuracy equipment and extensive network of survey monuments — along with the education, training and working knowledge of measurement and coordinate systems — that geolocation of existing features has become a surveyor’s specialty.
Access to this information and monuments is paramount to our profession as we would be limited greatly by eliminating the ability to utilize and reference them.
Not all who wander are lost
Because of the technology and miniaturization of GPS-capable devices, location capable electronics has become a multi-billion-dollar industry. It is almost impossible to not have a device with you at all times that will know where you are and how to get where you want to go.
Everything from cars to phones and computers to fitness trackers and watches has a GPS receiver to assist and track your every move. But it’s not just the GPS receivers that have revolutionized our world today; a big part of the geolocation system explosion was created due to the computer and innovative programming paired with it. We all know the application names: Facebook, Twitter, Instagram, Foursquare, Google Maps and so on.
These applications work so well because they know where we are based upon geolocation. Where’s the nearest McDonald’s or Starbuck’s? Any number of apps will show you and help you find the quickest route to get there.
Geolocation has also enhanced how people drive with apps like Waze and Google Maps using phone and car location data along traffic routes to gauge traffic speed, flow and congestion. Technology has improved almost everyone’s ability to travel, find places more efficiently and help bring people together at any location. Theoretically, possessing a GPS-enable device should eliminate ever being truly lost.
Was George Orwell right? Is Skynet next?
Technology, along with bringing good uses for applications and devices into our everyday lives, also brings possible issues as well.
Privacy advocacy groups are not a new concept, but the exploding use of electronic devices with GPS and geolocation capability has brought new life to their arguments regarding intrusion into our private lives. People sharing every detail of their lives opens up opportunities for identity theft and robbery by allowing critical data to be shared with the internet and all who use it. But the geolocation issue became a big privacy target with the phenomenal success of a smartphone app in the summer of 2016.
The humble beginnings of Pokémon started in Japan in the late 1980s with an arcade game created for the Nintendo Game Boy handheld console. The object of the game was to collect pocket monsters or Pokémon in various areas played within the game console. It became the second best-selling character-based game system ever, with more than 280 million copies sold on various platforms. Over the years, the game turned into a worldwide sensation featuring comic books, trading cards and even a popular television cartoon. It was this base knowledge of the characters and the concept of the game that led to the exploding sensation of Pokémon GO during the summer months of 2016.
Photo: Pokemon Go
This was the first mainstream app that blended a popular game with geolocation capability and a real-world environment, all tied together in an exercise to “catch ’em all.” The latest smartphones with high-speed streaming data provided the perfect game console for this new achievement for gaming with geolocation being a critical yet key component. Part of the lure of the game was catching many of the Pokémon in public parks and recreational areas, as they were placed there by game designers to allow easy access for players to find and collect.
Many of these public places were also historical, so local officials along with private citizens began complaining of large masses of players descending upon these sites and not being respectful of their surroundings. Stories of littering, vandalism, loitering and harassment were published nationwide, yet the game continued to draw players in by the thousands. While its popularity has waned toward the end of 2016, the concept of geolocation-based games left an indelible mark on the public and lawmakers who represent them as something they don’t want to see repeated.
Enter big bad government
Here in Illinois, lawmakers introduced proposed legislation in November 2016 to curb the use of various public and private locations from within geolocation-based video games on smartphones and handheld devices. Listed below are excerpts from the proposed bill language:
Section 1. Short title. This Act may be cited as the Geolocation Information Protection Act.
Section 3. Purpose. The purpose of this Act is to preserve the personal privacy of Illinois citizens when it comes to their highly sensitive geolocation information and to allow Illinois citizens to maintain control over the collection and disclosure of that information by private entities. This Act is also intended to provide real property owners, managers, and custodians with an easily accessible procedure for removal of ecologically sensitive sites or locations, historically significant sites or locations, sites or locations on private property, or sites or locations otherwise deemed as dangerous by the real property owner, manager, or custodian from location-based video games.
“Ecologically sensitive site or location” means an area designated by federal, State, or local government for protection from development or damage due to the presence of endangered species or threatened species as defined in Section 2 of the Illinois Endangered Species Protection Act
“Geolocation information” means information concerning the location of a device that is generated by or derived from, in whole or in part, the operation of that device and that could be used to determine or infer information regarding the location of a person. (Bold added for emphasis by author.)
“Historically significant site or location” means a site or location that has been designated by federal, State, or local government for preservation as a landmark, or any other site or location that the federal, State, or local government may designate as historically significant.
“Location-based application” means a software application that collects, uses, or stores geolocation information. (Bold added for emphasis by author.)
Section 20. Collection, use, and disclosure of geolocation information from location-based applications.
(a) A private entity may not collect, use, or disclose geolocation information from a location-based application on a person’s device unless the private entity first:
(1) informs the person in writing that his or her geolocation information will be collected, used, and disclosed;
(2) informs the person in writing of the specific purpose for which his or her geolocation information will be collected, used, and disclosed; and
(3) receives the person’s informed, written consent (including through an electronic means using the Internet) in a form distinct and separate from any form setting forth other legal or financial obligations of the person before collecting, using, or disclosing his or her geolocation information.
A voice for the surveyor was spoken loud and clear when the Illinois Professional Land Surveyors Association (IPLSA) contacted the bill’s sponsor regarding the content. We expressed our deep concerns with the limits this legislation would place on our profession, on our efforts to serve the public and eliminate the use of thousands of historical monuments throughout the state. The various state and national surveying associations and societies will continue to press our legislators for reasonable legislation that allows the public protection they request, yet will allow the professional surveyor to complete their jobs and serve that same public.
The bottom line is that privacy issues will continue to be a concern for most while technology progresses forward. Our environment is on the cusp of autonomous automobiles, virtual assistants and robotic equipment completely replacing our workforce.
Yes, we have gained many new exciting technological advancements with computers and programming, but also have given up a lot of information in the meantime to make it work for us. It is virtually impossible to have one without the other, so we will need to make a choice.
I hope we choose to continue progressing forward, yet realize we still need to have a memory of the past. A surveyor’s craft is heavily woven around the past, so let’s work together to make sure the critical stitching stays in place.
It has been a good year for all global navigation satellite systems (GNSS), as the chief executives of each system testify here. Alternative positioning, navigation and timing (PNT) also thrives. In this roundup of the latest highlights from the past year and forecasts for the future, 2017 augurs very well indeed! Let’s look at the newest alternative-PNT offerings first, followed by forecasts from the chief executive officers (CEOs) of each of the conventional GNSS.
Alternative PNT grows and expands
Two new entrants to the positioning, navigation and timing (PNT) marketplace offer key capabilities to fill in the gaps left by GNSS. A new satellite timing and location (STL) service from low-Earth orbit satellites, provided by Satelles and Orolia, gives a strong signal capable of penetrating buildings.
Satellite Time and Location (STL) Service. Pursuant to a recent announcement of new PNT solutions independent of GPS/GNSS signals, provided via the Iridium constellation, GPS World talked with Jean-Yves Courtois, CEO of Orolia. Orolia has partnered with Satelles to bring new PNT products and services to the global market, with a focus on military, and defense, government and commercial customers worldwide.
Jean-Yves Courtois, CEO of Orolia.
“We are a manufacturer and integrator of timing equipment,” Courtois said. Orolia is the parent company of GPS/GNSS product and service providers Spectracom, McMurdo and Spectratime. “This new STL service is not fully commercialized yet, but it’s operational and it can be tested. Receivers are available and can be integrated into our equipment.
“The timing signal is very accurate and close enough to GPS for most timing applications, although the positioning accuracy is lower than what GPS users are used to. It is an augmentation for timing primarily, and secondarily for positioning.
“In terms of timing accuracy, it provides on the order of tenths of microseconds in accuracy, and this covers a lot of timing applications, very familiar to us and to our customers. This is an ideal timing backup or augmentation of GPS. As number 2 worldwide in high-precision timing, we know this market and its applications very well.”
Correlator beamforming. The Locata Corporation announced a patented correlator beamforming technology to stem multipath mitigation. The new technique’s performance under rigorous testing by the U.S. Air Force Institute of Technology will be detailed in the January 2017 issue. Look for it! Here are a series of snippets as a preview of that lengthy technical article appearing in Richard Langley’s Innovation column.
“Unlike conventional or traditional beamsteering technology, the new correlator beamforming approach combines RF signals received by any number of individual antenna elements into a single switched-RF signal. This time-multiplexed signal is then downconverted and digitized by a single RF front-end. The correlator beamforming design will should offer cost savings because the resulting data stream is processed using a single correlator channel per beam. This markedly reduces the complexity when compared to the traditional beamsteering methodology.
“The correlator beamforming technique performs antenna array signal processing to form beams as part of a receiver’s correlation process. The complete explanation of this technology can quickly get complex, even for the seasoned RF engineer. To describe this process more simply, we will assume noiseless signals and no multipath (except as noted), as well as equal noise figures for all front-end processing chains. To further simplify our explanation, modulation on the carrier and switching losses will be ignored.”
“To evaluate the performance of correlator beamforming as fairly as possible compared to traditional beamsteering and single-element processing, AFIT set up its data collection such that all three approaches could be implemented in a software receiver. Additionally, a seven-element Naval Air Systems Command GPS Antenna System 1 (GAS-1) antenna was used for this experiment. The antenna was mounted on a 51-inch (130-centimeter) diameter rolled-edge ground plane provided to the ANT Center by the MITRE Corporation.”
“The testing focused on demonstrating an easily modified GNSS receiver to potentially deliver a low-cost solution for mitigating multipath — specifically targeting short delay and carrier multipath. The results presented here show that the multipath rejection performance nearly equals that of a traditional beamsteering GNSS receiver. Applications that can significantly benefit from this technology include stationary GNSS monitoring installations such as those used in satellite-based and ground-based augmentation systems and GNSS receivers for autonomous vehicles and UAVs in high multipath areas such as urban canyons.”
GPS III ready, steady
Col. Steve Whitney, Director, U.S. Air Force GPS Directorate
“The [GPS III] program is working to solve several technical challenges as we progress to completion,” Col. Steve Whitney, director of the U.S. Air Force GPS Directorate, wrote in GPS World’s December issue. “SV-01 testing uncovered electro-magnetic interference between a payload component and a hosted payload. Testing also uncovered electron impact issues on the L-band antenna elements. In partnership with Lockheed Martin, the program developed corrective action and design mitigations for both of these issues and is implementing these steps within our production flow for all the SVs.”
“In the coming year, SV-02, the second GPS III satellite, will also be progressing towards completing production. Currently, all of the SV-02 sub-assemblies have been received by Lockheed Martin and are being integrated into the spacecraft. The next major step in the production flow for SV-02 will be to mate it with its propulsion core.
“Recently, we completed negotiations with Lockheed Martin to extend the production line with purchases of SV-09 and SV-10. These satellites will be technically equivalent to SV-01 through SV-08. This $395 million purchase of two satellites marks a significant affordability milestone for the procurement of GPS III satellites.
“Looking ahead, we are analyzing how to acquire satellites beyond SV-10. We are executing a phased strategy which starts first with determining the viability of a GPS III production design existing beyond the current contractor. We awarded an initial phase of contracts to the Boeing Company, Lockheed Martin Space Systems Company, and Northrop Grumman Aerospace Systems in May 2016 to provide a feasibility assessment of the readiness of their satellites designs. In this phase, the contractors will provide a GPS III production design, manufacturing plans and a navigation payload brassboard test report, along with manufacturing/production processes and facilities maturity.”
Galileo coming on strong
Director of the Galileo Programme Paul Verhoef of the European Commission wrote in that same issue of the magazine, “The production of the satellites continues to maintain a steady rhythm, with a production line stretching from suppliers across Europe to OHB and SSTL and then to ESA’s ESTEC Test Centre in the Netherlands for acceptance testing, based on a wide range of simulated space tests.”
Paul Verhoef, director of the Galileo Programme and Navigation-related Activities, European Space Agency.
“The acceptance of the next satellites to launch is scheduled for this year’s end,” continued Verhoef. “Along with the two more Ariane 5 launches to come — one in the second half of 2017 and another in 2018 — the current plan is to commission further launch services as well as additional satellites in order to have Galileo fully operational by 2020. For these launches, Galileo may be the first customer of the new Ariane-6 launch vehicle.
“2017 will see the upgrade of various elements of the Galileo Ground Segment to reinforce its robustness, including updated releases to the Galileo Control Segment overseeing the satellites and the Galileo Mission Segment, overseeing the navigation signals. A new release of elements of the Galileo Security Facility, for security monitoring of the system, as well as the secure Public Regulated Service, will be deployed at the two Galileo Security Monitoring Centres.
“The Galileo Ground Segment will gain a sixth tracking telemetry and control facility, for monitoring the satellite platforms in Papeete, Tahiti, and additional processing chains for increased redundancy will be deployed across the Uplink Stations in Kourou, Reunion and Noumea used to update the navigation message information. Similar redundant chains will be finalized for all 15 current Galileo Sensor Stations, which perform continuous collection of Galileo signals to identify the tiniest clock error or satellite drift.”
EGNOS. “Along with the progress of Galileo, contracts are planned to cater for the further development of the ESA-designed European Geostationary Navigation Overlay Service, Europe’s first navigation system. EGNOS was certified for safety-of-life aviation use in 2011, and is managed by the European Commission through a contract with operator the European Satellite Services Provider, based in France. ESA will support the technical evolution of EGNOS version 3, intended as multi-constellation in nature, again through the Horizon 2020 framework.”
GLONASS looks forward to a new signal: CDMA!
Sergey Karutin, GLONASS Chief Designer, wrote “On the threshold of the first GLONASS-K2 launch, new GLONASS reference documents were published in October 2016, describing the family of code-division multiple-access (CDMA) radionavigation signals. The draft GLONASS Open Service Performance Standard has been developed. The GLONASS User Information Support System continues to evolve.”
From left: Sergey Karutin, GLONASS designer general; Nicolay Testoedov, director general, SC Information Satellite Systems; and Andrey Tulin, director general, SC Russian Space Systems.
“The system transmitting CDMA navigation signals is referred to in four interrelated interface control documents containing general information on signals and the detailed description of signal structures and digital message data. The new signals make it possible to include 63 satellites in the constellation, not only in circular medium-Earth orbit but also on geostationary and high-Earth orbits.
“The transition to the flexible string-type structure of the message data produces 2-second periodicity of integrity information delivery to users. The increased number of digits occupied by the ephemeris and clock parameters contributes to a better orbit and clock broadcast accuracy. The ephemeris broadcast precision improves from 0.4 to 0.001 meters. Time-stamp length in CDMA signal has increased to 30 bits, compared to 12 bits of frequency-division multiple-access signals.”
BeiDou approaches full regional services
Li Wang
“In 2017, three to four launches of BeiDou satellites will occur,” wrote Li Wang, Director of the International Cooperation Center in China’s Satellite Navigation Office. “BDS will provide basic services to the countries along the Belt and Road region by 2018, and possess global service capability by 2020.”
“BDS will keep improving its nationwide reference station network and steadily enhance its service performance. The dense reference stations for the nationwide frame network will be constructed by 2018, providing meter and decimeter level real-time location services for users in China, even centimeter level service in some areas.
“BDS will carry out the design, validation and construction of SBAS in accordance with international civil aviation standards. The first GEO satellite of BDSBAS will be launched in around 2018. The satellite-based augmentation services covering China and surrounding regions will be provided from 2020, to provide CAT-I services to civil aviation users.
“China will promote construction of a national comprehensive positioning, navigation and timing (PNT) system based on BDS, and strive to establish such a national PNT system with a united benchmark, no-gap coverage, security and effectiveness by 2030, as well as to upgrade capabilities to provide time and space information.”
Two important new signals — or rather, one signal and one group of signals — became available for military users worldwide last week. Satelles made an exciting announcement of what amounts to a new dimension in satnav: a whole new constellation in low-Earth orbit, bringing global coverage and most critically, a signal strength hitherto unknown to GNSS users. The satellite time and location (STL) has primary application in the timing realm, which is vital in many applications.
Higher in the sky, Europe’s GNSS satellites constituting the Galileo system officially began offering their services, and the multiple frequencies available here mean robustness, greater availability in obstructed environments, and — some say, though this is controversial — greater positioning accuracy, largely through more precise timing onboard.
Meanwhile, GPS World seeks a new defense editor for this column, and adopting the concept of “promoting from within,” now turns to its readership for interested parties to volunteer.
A New SatNav That’s Not GNSS
A strategic alliance announced on Dec. 15 between companies Orolia and Satelles includes will provide positioning, navigation and timing (PNT) solutions provided by the Iridium satellite constellation, independent of GPS/GNSS signals. The companies intend to provide PNT solutions to military, defense, government and commercial customers worldwide. Their new satellite timing and location (STL) service can supply much-needed robustness to GPS-dependent operations.
Orolia, the parent of GNSS-active companies Spectracomm, McMurdo, and Spectratime, has extensive experience in the defense realm. The company says it is #1 worldwide in the manufacture of military beacons outside the U.S. with a 60% market share, and #2 within the U.S., and that it is the first-ranked provider of Medium-altitude Earth Orbit Search and Rescue system (MEOSAR) worldwide. In partnership with Satelles, it will provide the STL service independent from traditional GPS and other GNSS satellite signals. STL is reported to be less susceptible to vulnerabilities such as spoofing, interference and jamming that are associated with GPS/GNSS — and the stronger signal penetrates buildings where GPS/GNSS cannot reach.
Iridium satellite, courtesy Iridium.
Based on the low-Earth orbit (LEO) Iridium satellite constellation, STL signals are up to 1,000 times stronger than GPS/GNSS; this signal strength, due in part to the constellation’s closer proximity to users, helps to prevent jamming and enables signal reach into buildings and other difficult locations. STL’s additional cryptographic security also enhances performance, productivity and security.
Projected key applications and use cases include energy/utility grids, enterprise data networks including financial systems, maritime/aviation navigation, fleet/asset tracking management, search and rescue and data center management.
“The timing signal is very accurate and close enough to GPS for most timing applications, although the positioning accuracy is lower than what GPS users are used to,” said Orolia CTO Jean-Yves Courtois. “It is an augmentation for timing primarily, and secondarily for positioning.”
“In terms of timing accuracy, it provides on the order of tenths of microseconds in accuracy, and this covers a lot of timing applications, very familiar to us and to our customers. This is an ideal timing backup or augmentation of GPS. As number 2 worldwide in high-precision timing, we know this market and its applications very well.”
“In positioning it’s closer to fifty meters or more. Much better for fixed objects than for mobile objects. The more mobile, the faster the vehicle, then the lower the positioning accuracy. It’s not directly usable for GPS applications that require a few meters accuracy, but it can be associated with inertial navigation for much better results.”
“The signal is encrypted, so you have to subscribe to a service to receive a key, allowing access to the signal. Applications are developing based on equipment that will be STL-enabled. For the user it will be transparent. The user will have a different antenna.”
“We are also active in tracking and emergency location devices, where this is also of interest. It has some authentication capability, to guarantee that the person who accesses the signal is in the location that he pretends to be.”
Galileo, live at last!
Also on Dec. 15, the European Commission issued the Galileo Initial Services Declaration. The Declaration of Initial Services means that the Galileo satellites and ground infrastructure are now operationally ready. These signals will be highly accurate but not available all the time, since the constellation is not yet complete and users cannot always count on four satellites being visible at one time at all points on the Earth.
Galileo has a significant role to play in military operations. It adds multiple frequencies to the GNSS palette, important for resistance to jamming. It adds satellites, and will add more in the new future, very important for signal availability. And its Public Regulated Service (PRS) is specifically designed with special features for security, defense and military operations.
I attended a GNSS Symposium recently in Australia where an academic expert repeated the oft-made assertion that Galileo is the only GNSS that is civil-designed and civil-controlled. At which point an industry expert leaned over, grabbed the microphone and growled “Yeah, right.”
No matter how you look at it, Galileo add important benefits to GPS for the suitably equipped warfighter.
This Newsletter Enters a New Era
Beginning in January 2017, this Defense PNT newsletter will combine with our GeoIntelligence Insider e-newsletter to offer broad coverage of both hardware and software matters, driven by GPS/GNSS, and enhancing the capabilities of security, defense, military and other government forces. Readers of both newsletters will receive the new combined edition as a matter of course.
Many readers will know of the recent passing of Don Jewell, the longtime editor of Defense PNT. We must soldier on, and GPS World hereby extends an invitation to readers of this newsletter — many of whom, we know, are military experts in your own right — who may wish to volunteer to fill Don’s position. Please write to [email protected] to request details, and please provide a brief outline of your background and experience.
A number of organizations are focusing on how inertial can help GNSS receivers to provide more stable, reliable position outputs when signals are hard to receive. Papers presented in September at the ION GNSS+ 2016 conference in Portland, Oregon, demonstrate that there is indeed a lot of focused effort in this area.
The conference showcased several integrated inertial GNSS solutions from a range of companies. For example, NovAtel is developing a novel way to make better use of lower precision MEMS inertial for certain land applications. Qualcomm is moving forward with a low-cost visual inertial to advance autonomous vehicle developments. And researchers in Germany from a university spin-off company are studying a multi-sensor solution.
Inertial integration aiding
Many people have heard about the NovAtel SPAN inertial/GNSS system. SPAN inertial-integration-aiding software has now been available integrated on NovAtel GNSS engines for a number of years. Combined with various external inertial packages providing real-time inertial aiding data, this system enables positioning outputs over a wider range of more difficult signal environments where GNSS alone might be too stressed to perform well.
According to the website, NovAtel currently offers SPAN with MEMS inertial products including various models from Honeywell, Litef, Analog Devices and Sensonor, along with a number of fiber-optic and high-precision tactical grade inertial measurement units (IMUs).
Recent SPAN development efforts have been focused on improving the performance of combined GNSS/SPAN/MEMS IMUs. The premise of the work is that in land-vehicle applications, a “land profile” can be applied that constrains velocity based on a range of acceptable vehicle dynamics. This includes applying limits to the cross track and vertical velocities of the vehicle.
In testing this land model, with equipment mounted in the NovAtel test van, three types on IMU were run through three different test scenarios. The IMUs were:
Epson G320 — Low power, small size MEMS IMU
Litef μIMU-IC — Larger tactical-grade performance IMU still based on MEMS sensors
Litef ISA-100C — Near-navigation-grade IMU using fiber optic gyros (FOG).
The three test scenarios involved environments with clear sky, partially obstructed sky view (downtown urban canyon) and a parking garage with no view of the sky and no satellite signal reception.
The Epson MEMS IMU appeared to be at a disadvantage from the beginning, given the higher performance units to which it was being compared. But NovAtel’s objective was to demonstrate that even this lower end device, when combined with GNSS, SPAN and the land profile, enables pretty good positioning results.
Test set-up.
Impact of SPAN land profile in GNSS denied testing.
The tests indicated that positioning with integrated higher performance units did not benefit to the same extent as when coupled with the low-end MEMS units in land-profile mode. Acceptable positioning was indeed possible with the Epson MEMS and when the constraints of land profile were able to limit position excursions when GNSS was lost, as in the parkade tests at Calgary airport shown in the figure above.
Ryan Dixon and Michael Bobye from NovAtel Inc. wrote this ION GNSS+ paper, “Performance Differentiation in a Tightly Coupled GNSS/INS Solution.” Ryan Dixon is the chief engineer of the NovAtel Synchronized Position Attitude Navigation (SPAN) GNSS/INS products, and Mike Bobye is a principal geomatics engineer at NovAtel Inc.
Visual inertial odometry
Qualcomm also presented some interesting results for the integration of visual inertial odometry (VIO) with GNSS. VIO measurements are constructed from a stream of camera frames combined with inertial measurements and can provide high-accuracy relative positioning. In experiments in a not-too-severe urban-canyon environment, this approach has been seen to reduce 95 percent horizontal error by two-thirds compared to GPS alone.
For applications such as autonomous vehicles and advanced driver assistance systems (ADAS), 50-meter errors, which can be typical for stand-alone GPS in urban canyons, just won’t cut the mustard. So Qualcomm has been looking for another source of aiding that would help reduce errors significantly.
The test set-up used a Sony Xperia Z3 phone as the source for the camera data and separate VIO processing, along with a single-frequency CSR SiRFstarIV GPS module on a custom hardware board for raw pseudorange and Doppler range-rate measurements. A high-precision NovAtel OEM6 GNSS/IMU SPAN-CPT module was used as ground-truth for position measurements.
Two scenarios were used to evaluate the proposed approach. The first scenario is an 870-meter drive in downtown Somerville, New Jersey, with a duration of 261 epochs. This represents a mild urban-canyon environment with loss of signal errors of a few tens of meters.
(Left) Part of the trajectory for the drive testing; (right) walkthrough building with no GPS coverage.
Results from the drive testing include several large GPS errors that the GPS+VIO solution is able to significantly reduce, while the walkthrough building tests appear to demonstrate a continuous GPS+VIO position solution.
“Robust Positioning from Visual-Inertial and GPS Measurements” was written by Urs Niesen, Venkatesan N. Ekambaram, Jubin Jose, Lionel Garin, and Xinzhou Wu, all of Qualcomm Research.
Multiple sensors
Finally, researchers at the Technical University of Munich (TUM) in Germany have focused on bringing outputs from as many sensors as economically feasible into an integrated GNSS solution. A precise model for multipath is included that applies amplitude, code delay, phase shift and Doppler shift for each reflected signal. The magnetometer measurements provide rough attitude information, which enables robust GNSS attitude ambiguity fixing.
The ANavS module integrates a multi-constellation u-blox GNSS receiver with a Sensonor 3D accelerometer/gyroscope/magnetometer, a Bosch barometer/thermometer and a built-in dual-band Taoglas GPS/GLONASS antenna. Real-time kinematic (RTK) positioning was tested by TUM students using the measurements from the multi-sensor module and a virtual reference station (VRS). A second multi-sensor module placed on the rear of the vehicle enabled attitude determination.
“Reliable RTK Positioning with Tight Coupling of 6 Low-Cost Sensors” was authored by Patrick Henkel, Technische Universität München, and Houcem Hentati, Advanced Navigation Solutions, Munich, Germany.
All of these options are providing GNSS with the support it needs in tight signal situations.
Q: What significant new developments in positioning, navigation or timing can we anticipate in 2017?
Dan Conway, Executive VP, Guidance & Stabilization, KVH Industries
A: With increasing focus on robust and resilient positioning, navigation and timing (PNT), the industry must respond with improved access to accurate and trusted position and timing, particularly for the warfighter. For military vehicles, this translates to a requirement for improved navigation systems that will provide commanders and onboard vehicle electronic systems with resilient PNT in contested environments. Secure and more robust navigation systems must now, more than ever, assure position and timing regardless of access to satellites.
Jeff Martin, VP of Business Development & Sales, Spirent Federal
A: Global navigation satellite systems have continually evolved, and 2017 should be no exception. With the scheduled launch of GPS III satellites, the world will see two new signals: M-code from a directional antenna and L1C (new civil signal). The European Galileo system may become operational. Russia is not expected to launch the new GLONASS K-2 satellites in 2017, but it’s not far off. Developers, integrators and users will have lots of options in 2017!
A: With approximately 65 percent of mass-market receiver chipsets already capable of multi-constellation tracking — and with this figure set to rise significantly in the near future — the demand for cost-effective but highly capable consumer goods with GNSS capabilities is clearly growing at an exponential rate. The forthcoming civilian signals offer huge opportunity to many sectors, but also present a challenge in the test and validation of new products, which will require highly capable and flexible simulation equipment.
A: Next year will bring huge strides in autonomous navigation. Multi-band high-precision GNSS will be a key enabler for robotics applications. Customers are demanding navigation solutions that are accurate, fast, robust and affordable. Multi-band enables convergence times measured in seconds, not minutes. Rapid time to first fix and reacquiring fix quickly after passing under obstructions will be essential for autonomous driving applications. Low-cost L1/L2 RTK GNSS will help bring these autonomous robotic applications to life.
I write at an especially exciting moment for the Galileo satellite navigation system, as two flagship European programmes combine for the very first time.
Mid-November will see the very first Galileo launch using an Ariane 5 launcher from Europe’s Spaceport in French Guiana, in place of the Soyuz that has served the constellation up until now. Four instead of two Galileo satellites will be launched at a time: The number of satellites girding the globe will rise at a single stroke from 14 to 18.
Meanwhile, the European Union is set to declare Galileo operational for initial services at the end of this year, bringing the system to the point where it can finally start serving users.
Paul Verhoef, director of the Galileo Programme and Navigation-related Activities, European Space Agency.
When Galileo Meets Ariane
November’s launch has been years in the making, employing a specially customized variant of Europe’s heavy-lift workhorse rocket called the Ariane 5 ES (Evolution Storable) Galileo. It has more powerful lower stages and a reignitable upper stage, first used in 2008 to supply the low-Earth orbiting International Space Station.
This new launcher design, adapted beginning in 2012 for Galileo, will carry a lower mass payload — four fully-fuelled 738-kg Galileo satellites plus their supporting dispenser — but must haul it to the much higher altitude of medium-Earth orbit, 23,522 km.
This precisely targeted orbit actually lies 300 km above the Galileo constellation’s final working altitude, leaving Ariane’s upper stage in a stable graveyard orbit, while the quartet of satellites maneuver themselves down to their final height.
Satellites. The satellites continue unchanged from those preceding them: Galileo full operational-capability (FOC) satellites with platforms from OHB in Germany and navigation payloads from Surrey Satellite Technology Ltd in the UK.
All 14 FOC satellites follow the first four in-orbit validation (IOV) satellites launched in 2011 and 2012; these four validated overall Galileo system design with the first wholly European navigation fix in March 2013.
Carrier. The four-satellite dispenser, the interface between the satellites and its launcher, is a wholly new design by Airbus Defence and Space. Its first role is to hold the satellites safely in position during their orbital flight and then to gently release them in separate directions. Its structure has been specially tuned to prevent harmful oscillations being triggered by the vibration and noise of launch. Its design was validated using complex finite-element modeling software, followed by practical testing of the dispenser together with dummy satellites.
Launcher. Ariane’s interstage Vehicle Equipment Bay, hosting the rocket’s avionic brain, underwent a redesign to reduce mass. Engineers also had to take into account this Ariane ES version’s flight time, much longer than any of its predecessors, more than four hours in all.
This involved a reworking of the launcher’s electronics and thermal subsystems, to ensure it maintains an optimal operational environment throughout a ballistic coast phase of more than three hours, between two firings of its EPS storable propellant upper stage. Two further Ariane 5 SE Galileo flights are planned to follow, one each for the remaining orbital planes.
Members of the joint Galileo Launch and Early Operations Phase (LEOP) team at work in CNES Toulouse. A joint team from ESA and France’s CNES space agency oversee Galileo LEOPs – the initial switching on and checking and configuration of satellite systems. LEOP is run from either ESOC or CNES Toulouse, on an alternating basis. (Photo: ESA)
Ground Control. This launch will mark the first time that ESA carries out launch and early operations (LEOP) for four satellites simultaneously. Usually, simply shepherding a spacecraft through the first critical days in orbit is a demanding enough task. A combined team from ESA and France’s CNES space agency based in Toulouse will make contact, establish control, and then see the four satellites through their initial critical activities. Within the combined team, each position is paired with a counterpart from the other agency to provide three mixed shifts around the clock for these first crucial days. This same team has conducted all Galileo early operations to date alternately from Toulouse or ESA’s ESOC control center in Germany.
The work starts with an initial check of on-board health and attitude, progressing to ensure each satellite’s pair of 1 x 5-meter solar wings are deployed and tracking the Sun, and then to point their antennas back towards Earth. Next comes a series of thruster firings to set the satellites onto a drift course into their final orbit, at which point they can be handed over to the Galileo Control Centre in Oberpfaffenhofen, Germany, for routine operations, and to ESA’s Redu Centre in Belgium to commence a few months of detailed payload testing.
Galileo at Your Service
Around the same time as this key launch, GSAT-210 and GSAT-211, the two previous satellites launched in May of this year, will have completed their in-orbit testing, allowing them to be formally certified as operational members of the constellation. The four new satellites should follow them into operational status by mid-2017. However, the Galileo system will reach initial operational status without these latest six satellites. The European Commission on behalf of the European Union expects to declare the system operational and ready to offer initial services before the end of this year.
This will mark a major milestone in the programme, awaited by many citizens in Europe and around the globe. Everyone with a Galileo-enabled receiver will be able to benefit from improved positioning, supplementing the already operational GPS constellation. ESA and the European GNSS Agency (GSA) have been working with European manufacturers of mass-market satnav chips and receivers to ensure that their products are Galileo-ready, offering detailed laboratory testing to close the loop between Galileo and industry.
Transition. In parallel to the declaration of initial services, there will also be an institutional change, as the GSA takes up its role overseeing the exploitation of Galileo. At the start of 2017, the formal handover of Galileo infrastructure will be initiated, targeted to conclude by the middle of the year. This mission includes not only the Galileo satellites in space but also the far-flung ground stations located on every continent, essential to the continued high-performance operations of the Galileo system. It also includes the two European Galileo control centers, with the signals overseen from Fucino in Italy and the platforms monitored from Oberpfaffenhofen, plus the communication infrastructure connecting them all together.
In the history of ESA, a research and development agency, this kind of handover to an operational body is not unprecedented; the agency handed Europe’s Meteosat weather satellites over to the newly created Eumetsat organisation, and pioneering telecommunication satellites came under the control of Eutelsat and Inmarsat. However, the Galileo ground segment will hold a special place in ESA history as one of the most complicated developments it has ever undertaken, serving to maintain the signals from the satellites to a nanosecond-scale of performance.
ESA will maintain its role of system design authority and system procurement agent, continuing to support system exploitation as it prepares for the follow-on Galileo Second Generation (G2G) design, supported through the EU’s Horizon 2020 programme. For example, the current contract of Galileo’s ground support operator will end next year, so ESA is supporting the GSA in initiating the contractual process to select a replacement operator. This contract covers all the interaction between the ground segment elements which are vital to the system as a whole. Maintaining continuity of service with transition to the new operator will certainly present a big challenge to the entire team, but one we are confident of meeting.
Upgrade. In parallel, 2017 will see the upgrade of various elements of the Galileo Ground Segment to reinforce its robustness, including updated releases to the Galileo Control Segment overseeing the satellites and the Galileo Mission Segment, overseeing the navigation signals. A new release of elements of the Galileo Security Facility, for security monitoring of the system, as well as the secure Public Regulated Service, will be deployed at the two Galileo Security Monitoring Centres.
The Galileo Ground Segment will gain a sixth tracking telemetry and control facility, for monitoring the satellite platforms in Papeete, Tahiti, and additional processing chains for increased redundancy will be deployed across the Uplink Stations in Kourou, Reunion and Noumea used to update the navigation message information. Similar redundant chains will be finalized for all 15 current Galileo Sensor Stations, which perform continuous collection of Galileo signals to identify the tiniest clock error or satellite drift.
New Satellites. The production of the satellites themselves continues to maintain a steady rhythm, with a production line stretching from suppliers across Europe to OHB and SSTL and then to ESA’s ESTEC Test Centre in the Netherlands for acceptance testing, based on a wide range of simulated space tests. The acceptance of the next satellites to launch is scheduled for this year’s end. Along with the two more Ariane 5 launches to come — one in the second half of 2017 and another in 2018 — the current plan is to commission further launch services as well as additional satellites in order to have Galileo fully operational by 2020. For these launches, Galileo may be the first customer of the new Ariane-6 launch vehicle.
EGNOS. Along with the progress of Galileo, contracts are planned to cater for the further development of the ESA-designed European Geostationary Navigation Overlay Service, Europe’s first navigation system. EGNOS was certified for safety-of-life aviation use in 2011, and is managed by the European Commission through a contract with operator the European Satellite Services Provider, based in France. ESA will support the technical evolution of EGNOS version 3, intended as multi-constellation in nature, again through the Horizon 2020 framework.
Finally, ESA is also addressing the challenges of satellite navigation beyond Galileo through the creation of the Navigation Innovation and Support Programme (NAVISP), which will be proposed to Europe’s space ministers for approval in December. Applying ESA’s expertise from Galileo and EGNOS, the optional NAVISP will undertake research work in support of ESA Member States’ national objectives and industrial competitiveness in the upstream and downstream navigation sector, including the fusion of satellite navigation with various disruptive technologies and complementary positioning techniques.
From left: Sergey Karutin, GLONASS designer general; Nicolay Testoedov, director general, SC Information Satellite Systems; and Andrey Tulin, director general, SC Russian Space Systems.
In October 2017 we will celebrate the 35th anniversary of the first GLONASS satellite launch. Since 1982, the capabilities provided by GLONASS satellites have multiplied and the system’s ground infrastructure has expanded beyond the Russian Federation.
Growing demand for satellite navigation services and increasing user requirements call for continuing modernization, which is only possible if advanced, technically complex solutions are employed, thorough efforts on design and in-orbit validation are made, and continuing dialogue with users is maintained to promptly react to their needs.
The stable operation of the third generation GLONASS-M satellites, the core of the today’s constellation, means more satellites are working beyond their design lifetime. In 2016, two single-satellite launches occurred, in February and May. Seven more satellites of this type remain in ground storage.
The reliability of on-orbit satellites forces us to develop new ground storage technologies since some satellites were manufactured more than three years ago, while the need for their launch may not arise until 2018. Therefore in the next two years the constellation will be sustained with this type of satellite.
The performance of the on-board atomic frequency standards (AFS) carried by the latest GLONASS-M satellites is considerably better than that of those carried by the first GLONASS-M satellites (see Figure 1). Their relative one-day stability has improved from 10-13 to 2.4× 10-14, contributing to smaller signal-in-space range errors (SISREs).
FIGURE 1. Estimation of the Allan Variation versus GLONASS System Timescale.
In February 2016, flight testing of the fourth generation GLONASS-K satellite was completed. It carries not only a cesium atomic-beam tube but a rubidium AFS for the first time in GLONASS history. The relative daily stability of this rubidium AFS is 4×10-14. As a result the SISRE for this satellite is about 1 meter.
We are also proud of the success of the passive hydrogen maser (PHM), which we have been building for almost 7 years (Figure 2). Multiyear ground tests displayed its excellent reliability and one-day stability of 5×10-15. It is expected to contribute to 0.3-meter SISRE. The PHM for flight tests measures 360×180×630 millimeters and weighs 25 kilos. Its power consumption is 54 watts. The PHM will be validated onboard the GLONASS-K2 satellite set for launch in 2018.
FIGURE 2. Passive hydrogen maser.
Passive hydrogen maser plot.
User Needs. On the threshold of the first GLONASS-K2 launch, new GLONASS reference documents were published in October 2016, describing the family of code-division multiple-access (CDMA) radionavigation signals. The draft GLONASS Open Service Performance Standard has been developed. The GLONASS User Information Support System continues to evolve.
The system transmitting CDMA navigation signals is referred to in four interrelated interface control documents containing general information on signals and the detailed description of signal structures and digital message data. The new signals make it possible to include 63 satellites in the constellation, not only in circular medium-Earth orbit but also on geostationary and high-Earth orbits.
The transition to the flexible string-type structure of the message data produces 2-second periodicity of integrity information delivery to users. The increased number of digits occupied by the ephemeris and clock parameters contributes to a better orbit and clock broadcast accuracy. The ephemeris broadcast precision improves from 0.4 to 0.001 meters. Time-stamp length in CDMA signal has increased to 30 bits, compared to 12 bits of frequency-division multiple-access signals.
The GLONASS Open Service Performance Standard, being drafted according to recommendations of the International Committee on Global Satellite Navigation Systems (ICG), is harmonized with the Performance Standard Template elaborated by the Working Group on Systems, Signals and Services of ICG with the active involvement of the Russian Federation.
As a result, it is also harmonized with the GPS, Galileo and BeiDou performance documents — in addition to international parameters like the horizontal and vertical availability, user positioning error (average and worst over Earth’s surface) and UTC broadcast error. The Draft Standard also includes:
PDOP availability (PDOP availability for the worst point on the Earth’s Surface, global average);
User Equivalent Range Error for the worst point of a satellite visibility cone (95%);
UTC(SU)-GLONASS Time offset broadcast error (global average 95%);
21 healthy satellites availability;
Per-slot availability;
24 healthy satellites availability;
Continuity (probability that a healthy satellite becomes unhealthy without notification 48 hours in advance);
Major failure probability (SIS URE of >75 meters).
GLONASS User Information Support infrastructure development is a complex program that covers establishing User Information Centers to raise awareness of all categories of users of the capabilities GLONASS provides and its guaranteed performance through www.glonass-iac.ru in Russian, English and Chinese languages.
The network of GLONASS-based navigation and information service providers is being developed. Services include satellite navigation activities, from emergency response to control of autonomous unmanned vehicles.
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