In consulting my notebooks for the spring of 2014, I find many remarkable cases that engaged the attention of my intimate friend Mr. Sherlock Holmes. Among them stand out the tragedy of the ancient British barrow, the disappearance of Pemblestoke the magician, and the curious facts associated with the giant rat of Sumatra, a tale for which the world is still not prepared. Perhaps none of these so well illustrate, however, the advanced technical insights and consultative powers of the great detective as did the intrigue into which we were drawn by the brilliant young American scientist, Geo. P. Hess.
“Watson, we have a new client,” Holmes announced over breakfast, “a friend, actually, upon whom I have depended for many years. He has always proved reliable, helping me navigate the highways and by-ways all across the land.”
“His name?” I inquired.
“The Right Honorable George Parkinson Hess from California, Colorado, Pennsylvania, Florida, and doubtless many other parts of the American nation. I have watched G.P. Hess grow these last 36 years into a prodigiously successful entrepreneur, known the world round for his ubiquity, openhanded generosity to all, and, equally, his devotion to his own country. Now it seems he needs my advice, and I cannot refuse him.“
“I wonder that an American should be able to find his way here this morning,” I replied. “There’s a beastly fog about, and London streets are no friendly environment under the best of conditions.”
“Have no fear, Watson,” Holmes chuckled. “I have never known G. P. Hess to be late for any function. Since a lad he was always on time, right to the second. You can set your watch by him, and as far as I know he has never been lost. He has an uncanny sense of direction and is indeed a fount of knowledge concerning maps and directions. I believe I hear his ring at the bell even now.”
Mrs. Hudson ushered in our American visitor, and Holmes introduced us. “It is always good to see you, G.P. How are you — in good health, I presume?”
“Indeed, Mr. Holmes, things are neither as well they may seem on the surface, nor as well as they could be. I am troubled of late, severely troubled by potential gaps in my future. Not to mention the seismic activity lately in Los Angeles. In the last 18 months, the magnitude of the tremors has grown from 3.1 to 5.1 on the Richter scale. I just can’t understand why they thought to have our major acquisition headquarters in a place that is constantly threatened by tremors, outright quakes, wild fires, floods, landslides, and tsunamis. Not to mention the traffic. It would have been much better to co-locate acquisition with the main headquarters in Colorado. All they have to worry about there are blizzards, high winds, and an occasional wildfire.
“While I could not agree with you more, G.P., I fail to see what I can do, try as I might, about Mother Nature.”
Fire in Florida
“Right you are, Mr. Holmes. I’ll get to the heart of the matter. I am deeply concerned about several of our business ventures: expansion and modernization efforts, if you will. You may have heard about a small but rather serious fire at the U.S. Air Force’s Cape Canaveral radar tracking facility and the subsequent launch delays. That small fire at a single tracking facility has already delayed a National Reconnaissance Office (NRO) launch, and a resupply mission to the International Space Station, currently manned by U.S. and Russian crews who, whether or not they are still speaking to one another, really need the replenishments. Now we aren’t allowed use Russian engine cores for space launch any more. A blessing, actually, as the Russians have put more malfunctioning GLONASS satellites into salt water lately than into the vacuum of space, when they aren’t simply blasting them to kingdom come.
“With all the troubles besetting Cape Canaveral, Elon Musk is burning figure eights in his Tesla, and SpaceX is a very happy company — in the right place at the right time, what? Able to launch its Falcons and Falcon Heavies from Vandenberg as well as Canaveral.
“Imagine, one little fire has caused the cancellation of several space launches, and those still on the manifest are moving to the right daily. We had hoped to put into orbit four new IIF models this year, but that looks next to impossible now. Plus it appears the GPS III payload has hit a snag. It is delayed six to nine months.”
GPS III Delay
“A delay in GPS III had not been looked for, had it?” queried Holmes.
“No sir, it had not. Everything was proceeding smoothly, but now the satellite payload is in question. Subcontractor Exelis has provided every GPS payload since 1978 and all have worked marvelously well, some of them for more than 23 years. But now — there is a problem. Some say it is signal crosstalk, some say it is with the new rubidium clocks. One thing for sure, it is demoralizing. I am given to understand the powers that be in Colorado Springs and Los Angeles are calmly but firmly looking for some competition or even an alternate payload provider.
OCX Delay
“And then there is the GPS ground segment. It has moved one month to the right for every month it has been in existence, it has gone over budget, and now is on its third program manager in three years. Whatever happened to the days when a capable leader conducted a program from beginning to end, knew it intimately from top to bottom, from soup to nuts? What is this world coming to? Where are our leaders?
“And don’t get me started on the effects of ‘seques-castration’!” fumed the young man.
“And the Chinese!” he continued, gathering steam. “Just who do they think they are? Do you know they called their regional system a PNT gold standard? Gold standard! Don’t make me laugh!”
“Now G.P., don’t despair,” soothed Holmes. “There are still excellent leaders out there, you just have to look a bit harder nowadays. In the space arena, Elon Musk, General William Shelton, Wild Bill Cooley, Frank Kendall, and Keoki Jackson are just five of many that come immediately to mind. Of course I would not want to play poker with any of them, but I digress.”
Solutions Appear
“I have been reading and thinking about the alternative payload issue,” the detective continued, “and I have other sources of information as well. Dr. Watson calls them my Baker Street Irregulars, and they are both resourceful and quite knowledgeable. These sources tell me there is another Colorado company, with excellent leadership, that is really on the ball, can move mountains (or huge boulders, anyway), and mark my words, they have top-notch crews, expertise, and even some past performance where an alternative GPS payload is concerned. They might be worth watching.
“As far as OCX goes, frankly I am hearing there are indeed backups and alternatives. My sources have confirmed the existence of a bracket of applicable technologies belonging to a small residual company, run by an Irish clan, believe it or not, with considerable past performance and expertise. Once officially launched to work on the real-time issues, they should be able to help the ground-segment team get back on the fast track.
“As for as the Chinese and their claims, all I can say is no one believes their gold standard rhetoric, although it obviously has a purpose.”
“Mr. Holmes, I hope you are right,” the American replied with an assuaged look. “I knew that if I talked with you I would feel better about these perplexing issues.
“I must resume my journey to Rotterdam, where I will hear a lot more about the Galileo program meeting its launch dates — or not — and the GLONASS outage. As rough a shape as we are in, we’re still far better off than the rest! In the meantime, I’ll pop over to Greenwich to synch up and universally coordinate with those folks before I move on to the Continent.”
G.P. Hess carefully scrutinized his pocket watch. “Now Mr. Holmes, Dr. Watson, I must depart. As you know I have a reputation to maintain: always precisely on time, never lost, and as far as I know, I have never blacked out. Cheerio!”
“What a remarkable fellow, Holmes!” I said after our client had left. “He is certainly full of energy.”
“Yes,” my friend replied, “energetic and very successful. If you had observed him more closely, Watson, you would have noticed his pocket watch. Ah, you did not remark upon it? Standard-issue, atomic-reference version, crafted of solid gold. You might say, and rightly so, that where time is concerned, G.P. Hess is the undisputed holder of the Gold Standard.”
So ends our brief visit with Holmes and the illustrious Watson. Stay tuned for further adventures, and until next time, Happy Navigating! G.P. Hess and I hope to see you all next week in Rotterdam, the Netherlands, at the European Navigation Conference, ENC-GNSS 2014. Drop by and say Hello!
If you can’t drop by and say hello in Rotterdam, the Netherlands, then please join me at the 30th Space Symposium, which is slated for May 19-22, 2014, at The Broadmoor Hotel in Colorado Springs. The Space Symposium is considered by many of us in the Space business to be the premier gathering of space professionals in the world.
In June, I will be attending the 39th NIST Time and Frequency Seminar. It has a great lineup of speakers this year to include: Judah Levine who is the NIST civilian time leader, David Allan who is the original creator of the famous Allan variance, and Neil Ashby, an expert in relativistic timing effects. The seminar takes place in Boulder, Colorado, June 3-6, 2014.
What Is Don Reading?
I had very little time for reading this month, or so I thought — then I had a brief but enlightening correspondence and conversation with local author George E. Nolly, who also lives in Colorado. George sent all four of his wonderful books direct to the Kindle app on my iPad. I had told George I was so swamped I would save his books to read on the airplane on my way to Rotterdam and report on them after the European Navigation Conference.
Then I read just one chapter of the first book and I was hooked. There was nothing for it but to devour all four volumes of the escapades of young Vietnam era USAF pilot, Hamilton “Hamfist” Hancock. Hamfist Out: The Chill Is Gone; Hamfist Over Hanoi: Wolfpack on the Prowl; Hamfist Down! Evasion, Survival and Combat in the Jungle; Hamfist Over The Trail: The Air Combat Adventures of Hamilton “Hamfist” Hancock
It will be like going back in time for many readers of a similar age. George Nolly writes with such an easy-going grace and fluidity that reading of these often stressful and life-threatening times, while sitting in my lounge chair, was, for me anyway, indeed a pleasure.
Certainly I can remember undergoing many of the same flying and ground ordeals, and Nolly tells his tales with such honesty and clarity that it brought back vivid memories. In fact I have never read such accurate descriptions of what it was like to fly the old T-29 with radial engines and all that entails. George actually brought back the unforgettable sound and smell of those two Pratt & Whitney R-2800 radial, air-cooled engines. They are from a long-forgotten era of aviation, but those of us who heard them will never forget them.
T-29A Aircraft, Vietnam era, restored. Courtesy of CONVAIR T29A.
George also makes wonderful plugs for GPS, possibly without knowing it, when he describes using LORAN maps under red lights in a cramped cockpit. This, along with all the time he spent just trying to figure out where he was or where the target was located, just screams for a GPS solution. In truth, in the Vietnam era we airmen spent a great deal of time trying to figure out exactly where we were, where our target was, and where the enemy was located, especially if he was shooting at us. Today all those tasks are made infinitely simpler with the use of GPS and modern electronics. However, this also highlights the amazing feats of airmanship accomplished in the Vietnam era, all while being constantly targeted by the enemy, all the more incredible.
Radial engine.
Just between us veteran airmen, the author relates the tales with such clarity and detail I suspect many of them are autobiographical. George E. Nolly, after graduating from the U.S. Air Force Academy here in Colorado Springs, served as a pilot in the United States Air Force, flying 315 combat missions on two successive tours of duty in Vietnam, winning three Distinguished Flying Crosses and 24 Air Medals, flying O-2A and F-4 aircraft, so he knows whereof he writes.
Even if you are a few generations younger than George Nolly and me, and don’t undergo a nostalgic experience as you read, you will certainly enjoy these fabulous books. Be sure to read them in order, as they are actually one running story that brings to life the trials, tribulations, and joys of Hamilton “Hamfist” Hancock for all of us and vividly recreates the way things were back in the 1960s and ’70s in the United States, the USAF, and what it was like flying in combat in Southeast Asia. I highly recommend these tales. I hope there are more to come.
Upcoming Conferences
If you can’t drop by and say hello in Rotterdam, the Netherlands, then please join me at the 30th National Space Symposium, which is slated for May 19-22, 2014, at The Broadmoor Hotel in Colorado Springs. The National Space Symposium is considered by many of us in the Space business to be the premier gathering of space professionals in the world.
In June I will be attending the 39th NIST Time and Frequency Seminar. It has a great lineup of speakers this year to include: Judah Levine who is the NIST civilian time leader, David Allan who is the original creator of the famous Allan variance, and Neil Ashby, an expert in relativistic timing effects. The seminar takes place in Boulder, Colorado, June 3-6, 2014.
“From the reports on GLONASS problems, we have an explanation that may be used in our technical support replies:
“Our analysis reveals the GLONASS integration algorithms skipped an interval of around 1.5 minutes at the control centre software.
“At 21:00 UTC April 1, all GLONASS satellites received an orbit state (ephemeris) which was clearly several minutes ahead of the current orbit shape without actually changing the applicable reference time stamp. In other words, future orbit-position, velocity and accelerations were assigned to a current reference timestamp.
“This led to incorrect orbit positions for all GLONASS satellites and subsequent problems with receiver using GLONASS measurements.
“In our receivers, RAIM rejected the solutions because of the large GLONASS errors, and could only work with GPS only and the recently revised RAIM settings for a Base (SRL,ON,-6,-4,-4).
“The issue is now rectified, and the GLONASS constellation is back to normal.”
Broadcom Corporation has announced the industry’s first 5G Wi-Fi (802.11ac) system-on-chip (SoC) to deliver pinpoint indoor positioning technology. The BCM43462 SoC, featuring Broadcom’s new AccuLocate technology, provides sub-meter accuracy on physical locations enabling retailers and public venue operators to deliver more personalized experiences to consumers.
Analysts predict the indoor location market to reach $4 billion in 2018, fueled by increasing demand for location-based services in public venues such as shopping malls, department stores, airports and stadiums. By leveraging location-based services, retailers and venue operators can offer discounts, promotions and personalized services to consumers based on exact locations while enterprise network IT staff can use the technology to track and manage assets, Broadcom said.
Broadcom’s latest 5G Wi-Fi SoC with on-chip AccuLocate technology operates using fine timing measurement (FTM) technology, resulting in highly accurate positioning regardless of environmental factors, Broadcom said. Previous versions of indoor positioning relied on received signal strength indicator (RSSI) technology, where signal strength and performance can vary depending on environmental factors such as crowd density or temperature.
“Broadcom’s latest 5G Wi-Fi innovation with integrated AccuLocate technology delivers highly accurate sub-meter pinpoint technology that rivals the capabilities of outdoor location based technology,” said Ed Redmond, Broadcom vice president and general manager, Compute and Connectivity. “In addition to providing a more customized user experience, this technology has the added benefit of allowing venue operators to monetize their investment in existing Wi-Fi infrastructure.”
“Location-based technology installations will break the 25,000 mark in 2014, while mobile devices capable of supporting indoor location will reach hundreds of millions within two years,” said Patrick Connolly, ABI Research senior analyst. “Rising demand for these services by the world’s leading venue operators and retailers is generating an immense opportunity for leading component suppliers, such as Broadcom, who are early to market with innovative solutions.”
About 5G Wi-Fi
Increased reliance on wireless networks, the explosion of video consumption and growing number of wireless devices are all putting tremendous stress on legacy 802.11a/b/g/n networks. With new innovations that allow for more reliable coverage, 5G Wi-Fi technology addresses these challenges, allowing mobile device users to stream digital content between devices faster, and simultaneously connect more wireless devices to home and enterprise networks, while conserving battery power.
Key Features of the Broadcom BCM43462 SoC
Dual-band (2.4 GHz and 5 GHz) complete 5G WiFi (11ac) SoC with integrated MAC, PHY and radio
Three-stream spatial multiplexing up to 1.3 Gbps
State-of-the-art security provided by industry standardized system support
Embedded hardware acceleration enables increased system performance
Full IEEE 802.11a/b/g/n legacy compatibility with enhanced performance
Support for FASTPATH® UAP, Broadcom’s enterprise class access point software
Availability
Broadcom’s BCM43462 SoC with integrated AccuLocate technology is now sampling. AccuLocate technology is also available on Broadcom’s BCM43520 5G Wi-Fi 2X2 SoC, BCM43460 5G Wi-Fi 3X3 SoC and BCM4354 5G Wi-Fi 2×2 MIMO Combo Chip.
Topcon Positioning Group announces a new data controller — the FC-500 — with numerous features and benefits, including a large 4.3-inch touchscreen display and 5MP camera with built-in LED flash.
The FC-500 is designed for the professional operating Topcon MAGNET Field, Site and Layout software and Topcon’s Pocket 3D.
Ray Kerwin, director of global surveying products, said, “The FC-500 works with all Topcon GPS/GNSS receivers and total stations, and meets or exceeds all field application requirements. Additionally, the FC-500 works with the new Topcon LN-100 instrument dedicated to BIM and one-person construction layout, simplifying workflow with the seamless integration with our MAGNET suite of software solutions.”
Kerwin said, “With a sunlight readable screen, the controller is easy to use even in bright sunlight. It is the ideal job site controller in any condition (waterproof up to one meter, IP68 rating) and the large camera format with built-in LED flash and built-in 8GB flash storage allows the storing of hundreds of job site photos.”
The standard model has both Bluetooth and Wi-Fi connectivity, while the FC-500 GEO has Bluetooth, WiFi and GPS. A third model comes with the addition of a 3.5G cellular modem that allows access to the MAGNET Enterprise Solutions suite, “making the FC-500 the perfect field instrument for sending and receiving data files to the MAGNET cloud,” Kerwin said.
For the GIS professional using MAGNET Field software, the FC-500 has a geotagging feature that allows imprinting file information, including GPS location, directly on photos.
Yesterday we posted news of an 11-hour downtime for the full GLONASS constellation, due to an upload of bad ephemerides. Coincidentally, during that 11-hour period, the mass-market chip company Broadcom was conducting multi-constellation receiver tests in Asia. Frank van Diggelen, Broadcom’s chief GNSS scientist and vice president says, “We have definitive data to show how a multi-constellation receiver survives such an outage.”
Here are the pictures, and the story they tell.
Test data coincident with the GLONASS ephemeris disruption of April 1 and 2 showing conclusively how a GPS/GLONASS/QZSS/BEIDOU receiver survives the complete disruption of one of the constellations.
On April 2 at 1:00 a.m. Moscow time, bad ephemeris was uploaded to all satellites (see chart at the bottom of this story).
There are two receivers shown here, from two different manufacturers, both in smartphones. The yellow dots are for a GPS/GLONASS receiver; the blue dots are from the Broadcom 47531 receiver which tracks GPS/GLONASS/QZSS/BeiDou signals simultaneously. The 47531 receiver includes logic to use redundant measurements to check the validity of all measurements. It successfully identified and removed the bad GLONASS ephemeris 100 percent of the time, as can be seen by the continuity and accuracy of the positions.
Here is the satellite outage chart from yesterday’s story. All GLONASS satellites were restored to healthy state after the 11-hour interruption.
Current plot from the Roscosmos GLONASS Information-Analytical Centre. Things are almost back to normal this morning.
By Mirko Stanisak, Mark Bitter, and Thomas Feuerle
INNOVATION INSIGHTS by Richard Langley
GPS = SAFER FLIGHT. While reviewing material for an article celebrating the 25th anniversary of the launch in February 1989 of the first Block II or operational GPS satellite, I was yet again annoyed by many articles on the Web stating that GPS only became available for civil use after the launch of this satellite. Some sources get closer to the truth when they say that GPS was opened for civil use in 1983, following the shoot-down of the Korean Airlines Flight 007. In fact, GPS was designed to serve the needs of both the military and civil communities from the outset. A government memo from April 1973 clearly states: “Civil user needs should be considered in the design of the spaceborne equipment.”
One of the first demonstrations of the use of GPS for aircraft navigation occurred in July 1983, when a Sabreliner business jet was flown in stages from Cedar Rapids, Iowa, to the Paris Air Show, flying only when a sufficient number of the experimental or Block I satellites were in view. The first standalone GPS receivers certified for aviation use (with Receiver Autonomous Integrity Monitoring or RAIM) became available by the mid-1990s. But already the Federal Aviation Administration had been looking into the development of a system to provide higher accuracies and better integrity than that afforded by standalone receivers. In 1994, the FAA announced the development of the Wide Area Augmentation System, its brand of a system generically known as satellite-based augmentation. Geostationary satellites transmit corrections and integrity information to GPS receivers, permitting GPS use for en route navigation all the way down to traditional Category I approach and landing. CAT I approaches can be flown down to a decision height of 61 meters (200 feet). WAAS was declared operational on July 10, 2003, but enhancements to the system continue. Japan, Europe, and India also have operational SBAS based on GPS.
Ground-based GPS augmentation was first developed for maritime applications with the U.S. Coast Guard’s low-frequency system coming on line in the mid-1990s. Also in the mid-1990s, the FAA began the development of the Local Area Augmentation System, generically known as a ground-based augmentation system (GBAS), to provide aircraft with approach and landing capabilities from CAT I down through CAT II (30-meter or 100-foot decision height) and CAT III (no decision height but certain visual range minima) using a VHF datalink. Initial CAT I systems are being operated at Bremen, Germany, and at Newark Liberty International Airport and Houston George Bush Intercontinental Airport.
While a GPS-based GBAS will definitely offer improved navigation services for aircraft, might these services be even better if the systems were to use satellites from other constellations besides GPS? In this month’s column, we look at a straw-man concept for modifying the GBAS protocols to accommodate multiple constellations and the results of preliminary tests using GPS, GLONASS, and Galileo simultaneously.
“Innovation” is a regular feature that discusses advances in GPS technology and its applications as well as the fundamentals of GPS positioning. The column is coordinated by Richard Langley of the Department of Geodesy and Geomatics Engineering, University of New Brunswick. He welcomes comments and topic ideas. Write to him at lang @ unb.ca.
Ever since the declaration of Full Operational Capability (FOC) of the U.S. Global Positioning System in April 1995, GPS has dominated satellite navigation, especially in aviation applications. By contrast, the Russian GLONASS system cannot be used in western aviation because no approval guidelines exist for GLONASS equipment. Thus GPS has been the de-facto standard in aviation for years.
However, within the last few years, major changes have evolved in the field of GNSS, providing a wide variety of useable satellite navigation systems. The European Union launched its Galileo project, which will provide global multi-frequency services in the near future. China is upgrading its BeiDou system (formerly called Compass) to provide global coverage with more medium-Earth-orbit (MEO) satellites. The operators of GPS and GLONASS have started modernization programs that will enable multi-frequency operations in the future, too. Therefore, a large number of usable satellites and signals from multiple systems will soon be available.
In aviation, almost all phases of flight can be assisted by satellite navigation systems nowadays. The most challenging phase of flight with respect to accuracy, continuity, availability, and integrity is the approach and landing phase. The Ground Based Augmentation System (see FIGURE 1; courtesy of the European Organization for Civil Aviation Equipment) allows precision approaches to be performed using satellite navigation. It uses a VHF data link to broadcast differential GNSS corrections, integrity information, and approach definitions to approaching aircraft. These aircraft combine the differential corrections with their own GNSS measurements, calculate a GBAS-corrected position solution, and determine path deviations based on the selected approach.
FIGURE 1. GBAS principle. (Source: EUROCAE WG 28, ED-114)
From a technical perspective, GBAS can use either GPS or GLONASS for differential corrections. For this, the International Civil Aviation Organization (ICAO) Standards and Recommended Practices (SARPs) include GPS and GLONASS side by side. On the other hand, some standardization documents (for example, those from RTCA) are limited to GPS only, effectively excluding GLONASS from being used in the western world. Nevertheless, Russian GBAS systems provide differential corrections for GPS and GLONASS, and are expected to be certified in Russia in the near future. Additional GNSS such as Galileo or BeiDou are not yet included within these documents, as these systems are not approved for aviation use themselves. This article will focus on how a multi-constellation GBAS with GPS, GLONASS, and Galileo could work.
GBAS installations can provide multiple services for different kinds of operation, based on GNSS L1 corrections only. On the one hand, the differentially corrected positioning service (DCPS) is intended to be a generic service for high accuracy positioning. On the other hand, two different GBAS approach services have been defined. GBAS Approach Service Type C (GAST-C) allows Category I (CAT I) procedures and is already in operation. GAST-D is still under development and will enable precision approaches and landings down to CAT II/III minima once certified. To mitigate all possible hazards, GAST-D will require some additional broadcast messages.
VHF Data Broadcast
The VHF Data Broadcast (VDB) is used to communicate binary GBAS messages to approaching aircraft. It operates in the VHF band (108.025 – 117.975 MHz) and uses time-division multiple access (TDMA) to allow the operation of multiple GBAS ground stations on a single frequency. As shown in FIGURE 2, VDB uses UTC time to have a common time frame. Two frames are transmitted each second, lasting 0.5 seconds each. Within each frame, eight slots with durations of 62.5 milliseconds can be used for transmission. Binary application data is encoded using a differentially encoded eight-phase-shift-keying modulation (D8PSK) and a symbol rate of 10,500 symbols per second. With three bits transmitted per symbol, up to 31,500 bits per second can be transmitted. Each slot can contain up to 222 bytes of binary application data. Usually, only a subset of slots is allocated to a particular ground facility. This way, multiple GBAS ground facilities can share a common VDB frequency.
Within each slot, multiple VDB messages can be transmitted as application data. The coding of information in VDB messages is defined in the RTCA’s GNSS-Based Precision Approach Local Area Augmentation System (LAAS) Signal-in-Space Interface Control Document (ICD) and depends on the VDB message type. (LAAS is the U.S. GBAS.) Currently, message types (MT) 1, 2, 3, 4 and 11 are defined. Figure 2 is derived from this document.
Message Type 1 – MT1. Within VDB Message Type 1, differential corrections based on 100-second smoothing are transmitted. These corrections are required by all GBAS approach services (GAST-C and GAST-D). Aside from the differential corrections, additional information for the first broadcast satellite is transmitted. This includes an ephemeris cyclic redundancy check (CRC), mitigating the effects of wrongly received GNSS navigation data, and the Issue of Data (IOD) flag, indicating the time of applicability for the ephemeris data to be used. To transmit this information for all satellites, the satellite for which differential corrections are transmitted first has to be alternated continuously.
Each MT1 message can contain up to 18 pseudorange- and range-rate corrections for individual satellites. Nevertheless, it is possible to link two consecutive MT1 messages using the Additional Message Flag (AMF). The value of this parameter indicates whether this is a single message (0), or the first (1) or second (3) part of a linked MT1 message. Up to 36 differential corrections can be transmitted using two consecutive VDB time slots with 18 corrections each.
All MT1 measurement blocks must be transmitted at least once per frame. The maximum transmission rate is once per slot for all measurement blocks.
Message Type 2 – MT2. VDB Message Type 2 contains station and integrity parameters such as the coordinates of the reference point to which all differential corrections refer. MT2 messages can include (next to a “core” MT2 message) multiple Additional Data Blocks (ADBs) to transmit information required for different GBAS services. At the moment, the Additional Data Blocks 1, 3, and 4 are defined.
ADB1 contains the maximum distance to the reference point at which the corrections may be used (Dmax) as well as parameters to calculate the remaining risk of incorrect GNSS ephemeris data (Kmd,e). Within ADB3, additional information required for GAST-D is transmitted. ADB4 implements the VDB authentication feature. If this ADB is broadcast by a ground facility, MT2 messages must be transmitted first and contain additional indications about which VDB slots are allocated to the ground facility.
MT2 messages must be transmitted at least each 20th frame, but may be repeated up to once per frame.
Message Type 3 – MT3. The VDB Message Type 3 is a fill message, which is only used in conjunction with the GBAS authentication feature (MT2, ADB4). Among other things, this feature requires a minimum slot occupancy of at least 95 percent. Thus, MT3 messages are broadcast only by ground facilities that support the authentication feature and are completely ignored by airborne GBAS receivers.
Message Type 4 – MT4. With VDB Message Type 4, approach information can be broadcast to approaching aircraft. A pilot can select a specific approach by simply tuning to a given channel number.
Currently, GBAS only uses Instrument Landing System look-alike straight-in approaches called Final Approach Segments (FAS). Each FAS represents one approach. This way, a single GBAS ground facility can provide multiple approaches for all runways of an airport. All approaches must be broadcast at least once per 20 consecutive frames.
Message Type 11 – MT11. The VDB Message Type 11 provides differential corrections in a way very similar to MT1 messages. The main difference is that MT11 corrections are based on 30-second smoothing, which is required for GAST-D service. As for MT1, all MT11 measurement blocks must be transmitted at least once per frame.
Enhancements for GBAS with Galileo
At the moment, the GBAS standardization documents include information on GPS, GLONASS, and SBAS ranging sources. No information on Galileo or other constellations has been added yet. Thus, to include Galileo for GBAS, some Galileo-specific experimental additions to the standards are necessary. These proposed modifications have been made in such a way as to keep as close to the other system standards as possible to preserve consistency. This way, hardly any new functionality is added, but additional satellites can be used. The additional Galileo signals (E5a, E5b, E6) are not used at the moment; however, they might be highly beneficial for multi-frequency applications in the future.
All modifications presented here are purely experimental and will most probably not be exactly the same as those in future standards documents. Nevertheless, they provide a way to test Galileo together with GPS and GLONASS for GBAS on an experimental basis.
Ranging Source ID. The Ranging Source ID uniquely addresses a single satellite. It is used in MT1 and MT11 to transmit the differential corrections and other information for each ranging source. In ICAO Annex 10, Standards and Recommended Practices, the Ranging Source ID is defined for GPS, GLONASS, and SBAS only. To provide Galileo corrections as well, an experimental mapping for Galileo satellites was added; see TABLE 1.
TABLE 1. GBAS Ranging Source IDs.
In this way, up to 36 Galileo satellites can be addressed.
Navigation Data. Galileo provides two different sets of navigation data. The I/NAV data corresponds to the Safety-of-Life (SoL) service and is broadcast on E1 and E5b. The F/NAV data corresponds to the Open Service (OS) and is broadcast on E5a. In order to remain as close as possible to the legacy navigation systems, we selected the I/NAV navigation data for use, as it is broadcast on the E1 frequency and can thus be received with an L1-only GNSS receiver.
The navigation data is primarily used in VDB MT1. For the first transmitted correction in this message, the ephemeris set that shall be used in the aircraft is identified via the Issue of Data (IOD) field. To be consistent with the GPS ephemeris, we used Galileo’s IODnav parameter.
Together with the identification of the navigation data, a CRC parameter is transmitted in MT1 for the first satellite within the differential corrections. This parameter ensures that the receiver as well as the ground facility use identical navigation data for all calculations. The CRC algorithm uses the raw navigation data to generate a distinct CRC value.
For GPS and GLONASS, two ephemeris masks are defined. These masks ensure that only information relevant for GBAS processing are covered by the CRC. For Galileo, a similar mask had to be designed.
Additional Data Blocks in MT2. Within VDB MT2, station parameters and integrity information are transmitted. Some parameters for the over-bounding of possible ephemeris errors are specific to each satellite navigation system.
To extend MT2 to Galileo, parameters for the DCPS, GAST-C, and GAST-D must be added for Galileo. For downward compatibility, these parameters cannot be included in the existing Additional Data Blocks beside the existing parameters. Thus, a new Additional Data Block (ADB5) was defined on an experimental basis. This Additional Data Block is dedicated to Galileo and is structured as shown in TABLE 2. The coding of all values corresponds to the coding of the parameters for the existing systems.
TABLE 2. Additional Data Block 5 in Message Type 2 for Galileo parameters.
Optimized VDB Transmission Scheme
Having available a large number of ranging sources for differential corrections, the VHF VDB is a bottleneck for the transmission of this data. To demonstrate this, we first consider the number of visible satellites that there will be in the future. This leads to construction rules for an optimal VDB transmission scheme, which allows transmitting the maximum number of differential corrections.
Number of Satellites Available. To demonstrate the number of differential corrections enabled by the different systems in the future, we computed the number of visible satellites over a day for a stationary GNSS receiver in Braunschweig, Germany. Even though only four Galileo satellites were in orbit at that time, up to 26 different satellites (GPS, GLONASS, and Galileo) were in view simultaneously. Keeping in mind the preliminary Galileo constellation, it is obvious that more than 30 satellites will be available simultaneously in the future — considering only GPS, GLONASS, and Galileo. Adding BeiDou satellites for GBAS would further boost these numbers.
The broadcast of such a large number of differential corrections is limited by the capacity of the VDB and thus by the number of slots assigned to a GBAS ground facility. The number of assigned slots for a facility should be limited as far as possible to be able to use the same frequency for other GBAS ground facilities. Thus, the available capacity must be used as effectively as possible.
Number of Bytes Required. Each VDB message is framed by a message block header (6 bytes) and the message block CRC (4 bytes).
The length of each message depends on the message type and the amount of information to be transmitted. The resulting length for a message of each type is given in TABLE 3.
TABLE 3. Size of different VDB message types (including message block header and CRC). Variable length message types are dependent on the number of corrections, N.
VDB Constraints. A GBAS ground facility must transmit the VDB data following some constraints. These are:
MT2 messages (including all Additional Data Blocks required) must be transmitted at least each 20th frame (that is, every 10 seconds).
If authentication is required, each MT2 message must be transmitted in the first slot assigned to the GBAS ground facility.
All differential corrections (both MT1 and MT11) must be transmitted at least once in each frame. However, it is possible to split the differential corrections into two adjacent slots using the Additional Message Flags in MT1 and MT11 messages.
Within each MT1 message, the ephemeris decorrelation parameter (Peph), the Issue of Data (IOD), and the ephemeris CRC is transmitted for the first satellite in the message. Thus, the first satellite must be alternated in order to broadcast the ephemeris information for all satellites.
Approach definitions are transmitted in MT4 messages. All MT4 messages must be transmitted within at least each 20th slot.
Based on these constraints, a VDB encoding scheme has been developed, which allows us to fulfill all the requirements listed above while optimizing the number of differential corrections that can be transmitted. Even though it is optimized for GAST-D-like services (including authentication parameters, MT11 messages, and experimental Galileo extensions), it can be used for legacy GAST-C systems, too.
Rules for Optimal VDB Transmission. To fulfill the requirement for the MT2 message to be transmitted first, a complete MT2 message must be transmitted each 20th frame at the beginning of the first slot assigned. If no MT2 message has to be transmitted, an MT4 message is transmitted instead. Thus, all messages are arranged in proper order by three simple rules:
MT2 (each 20th frame) or MT4 (otherwise)
MT11 (all corrections; can be split into two messages)
MT1 (all corrections; can be split into two messages).
Additionally, two more rules must be fulfilled. On the one hand, if supporting the authentication feature, each slot in which the ground facility may transmit VDB data must be filled to at least 95 percent. For this, MT3 null messages may be used to ensure that each slot is filled sufficiently. On the other hand, an additional rule for MT1 messages is necessary if more than three slots are assigned to the GBAS ground facility. In this case, to maximize the number of differential corrections the MT1 messages may be transmitted in the last two assigned slots only. This rule is necessary because the Additional Message Flag is limited to two slots for differential corrections.
Using this transmission scheme, the number of differential corrections is maximized while fulfilling the minimum requirements on the VDB data. Even in case of the maximum number of differential corrections, MT4 approach definitions can still be broadcast. However, in this case, the number of transmittable FAS segments is limited to 19. If more approaches (or different approach types such as Terminal Area Paths (TAPs)) have to be transmitted, the VDB generation scheme must be adapted.
Number of Transmittable Corrections. Using the optimized transmission scheme explained earlier, the number of transmittable corrections can be calculated easily for different numbers of assigned slots for GAST-C as well as for GAST-D services (see TABLE 4).
TABLE 4. Number of differential corrections that can be broadcast.
The exact distribution of VDB messages for the maximum number of differential corrections (18) is shown in FIGURE 3 for an MT1/MT11 configuration and two assigned slots.
FIGURE 3. VDB messages for two slots and 18 satellites (MT1 and MT11).
Experimental Realization of Multi-Constellation GBAS
The experimental GBAS multi-constellation extensions described earlier have been implemented in software for further testing. As these enhancements are purely experimental and might change in the future, we have ensured that these definitions can be changed easily.
Navigation Software. The Institute of Flight Guidance at Technische Universität Braunschweig has been developing an experimental navigation framework for many years. This software, called TriPos, can handle and combine different navigation technologies. TriPos can be used for simulations, post-processing of recorded data, and even for live (online) processing. It is written in C++ and supports various platforms.
The navigation framework can be extended easily. Originally, only GPS was supported within the software, but support for GLONASS and Galileo as well as augmentation systems like SBAS and GBAS were added over the past few years. Additionally, the software handles GNSS data of multiple frequencies internally and can thus be used for multi-constellation and multi-frequency applications. TriPos includes decoders for the binary protocols of most GNSS receivers currently available.
For GBAS research, two components can be simulated using the software. On the one hand, the Ground Facility simulation calculates the differential corrections and provides simulated VDB data. On the other hand, the GBAS receiver simulation emulates the behavior of an airborne GBAS receiver and uses VDB data and GNSS measurements to calculate a GBAS solution. Both simulations can use either recorded data in post-processing or live data for online-processing. This allows complete simulation of GBAS.
Multi-Constellation GBAS Ground Facility Simulation. The GBAS ground facility simulation uses raw binary data from multiple stationary GNSS receivers to calculate binary VDB data. The simulation can be freely configured to process either live or pre-recorded GNSS data. Even though it features all algorithms required by the standards, it does not contain additional monitor algorithms at the moment.
Nevertheless, it can provide a valid VDB signal-in-space (SIS), which can be used by GBAS receivers and simulation tools (such as Eurocontrol’s PEGASUS tool). The ground facility simulation supports legacy GBAS CAT-I (GAST-C) as well as GAST-D (including all additional VDB information required) using GPS and GLONASS. Support for Galileo has been added according to the experimental definitions described earlier. In addition to FAS data blocks, the ground facility simulation is also capable of providing curved approaches using TAP data blocks.
Multi-Constellation Airborne GBAS Receiver Simulation. The GBAS receiver simulation has been used for various GBAS-related projects. It supports GAST-C as well as GAST-D and can be configured flexibly to use GPS, GLONASS, and/or Galileo (using the experimental enhancements as described earlier). For GAST-D, all airborne monitoring algorithms required are present. Thus, the aircraft-specific parameters (for example for the airborne geometry screening) can be configured together with the other parameters.
Flight Trials
The practicability of the multi-constellation GBAS approach has been tested in flight trials. To ensure that all four Galileo satellites were in view and capable of providing valid data during our trials, an orbit prediction tool and the Notice Advisory to Galileo Users (NAGU) service of the European GNSS Service Center (GSC) were used prior to the flight.
The data processing configuration is shown in FIGURE 4 and includes the GBAS simulation components explained earlier. All processing is done in real time while recording all data for later post processing.
FIGURE 4. Schematic data processing for the flight experiments (ground components in orange, airborne components in blue).
Ground Processing. On the ground, two Septentrio AsteRx3 GNSS receivers connected to two roof-top antennas were used. The GNSS receivers were connected to the GBAS ground facility simulation via a network and provided binary GPS, GLONASS, and Galileo raw measurements with an update rate of 2 Hz as well as navigation data. Using this data, the ground facility simulation generated binary VDB data. The GBAS ground facility simulation was configured to generate multi-constellation GAST-D VDB data for a three-slot configuration. All required messages (MT1, MT2 including all required ADBs, MT3, MT4 and MT11) were generated and sent to the telemetry facility via the network.
Telemetry. Official VHF data broadcasts operate in a frequency band between 108 and 118 MHz, which is reserved for authorized aviation applications. However, for our experimental system, an alternative data link was used. The Institute of Flight Guidance operates a full-duplex telemetry system to share data between ground and aircraft. Even though the operating frequencies are different, the telemetry system allows the generated binary VDB data to be transmitted to research aircraft. The airborne telemetry receiver outputs data as if it were a VDB receiver to allow us to switch between a real VDB receiver and the telemetry receiver easily.
Research Aircraft. The Institute of Flight Guidance operates the research aircraft of the Technische Universität Braunschweig. The Dornier Do 128-6 with the call sign D-IBUF (see FIGURE 5) is a twin-engine turboprop aircraft without a pressurized cabin and has been used multiple times for GBAS-related research over the years.
FIGURE 5. Research aircraft D-IBUF (Dornier Do 128-6).
The research aircraft allows us to flexibly integrate experimental equipment for specific flight trials. For the multi-constellation GBAS flights, a JAVAD Delta GNSS receiver (capable of multiple constellations and frequencies), a telemetry receiver, and an experimental cockpit display were installed temporarily.
Airborne Processing. The online GBAS receiver simulator uses GNSS data from the JAVAD Delta GNSS receiver together with the VDB data received via telemetry. The receiver was configured to output raw GPS, GLONASS, and Galileo measurements with an update rate of 10 Hz. The simulator was configured to use this data to calculate a multi-constellation GAST-D solution. Based on the selected approach definition, the resulting information (deviations, distance to threshold, and so on) was displayed in the cockpit using an experimental cockpit display.
Results. The flight test was conducted in the evening of November 6, 2013 (16:52 – 17:58 UTC), at Research Airport Braunschweig (EDVE). We performed five approaches with a 10 nautical mile final segment. The flight path as calculated by the GBAS receiver subsystem is shown in FIGURE 6.
FIGURE 7 shows the number of satellites used for the GBAS receiver simulation, and distinguishes between the different satellite navigation systems used. Up to 22 satellites have been used simultaneously for GBAS processing, including up to 10 GPS satellites, eight GLONASS satellites, and four Galileo satellites.
FIGURE 7. Number of satellites used by the multi-constellation GBAS receiver simulation.
Even though no certified GBAS equipment was used for the flight trials, FIGURE 8 shows the resulting vertical and lateral protection levels (VPL and LPL) of the online multi-constellation GBAS receiver simulation. Both values fluctuate due to the differences between 100- and 30-second smoothing position solutions, which have to be added to the protection levels for GAST-D. Nevertheless, both sets of values remain clearly below the corresponding Alert Limits (FAS Lateral Alarm Limit (FASLAL): 40 meters, FAS Vertical Alarm Limit (FASVAL): 10 meters). A valid GAST-D service was achieved continuously.
FIGURE 8. Vertical and lateral protection levels (VPL and LPL).
FIGURE 9 shows a vertical integrity diagram, commonly known as a Stanford plot, for the integrity of the multi-constellation GBAS simulation. This plot shows the Vertical Protection Level (VPL) as determined by the GBAS receiver simulation against the actual Vertical Position Error (VPE). The Vertical Position Error is a direct measure for the Vertical Navigation System Error (V-NSE). This has been determined using a precise point positioning reference trajectory. Both values are normalized by the current VAL as these values change during the approaches. During the flight, the GBAS online processing ran at a rate of 10 Hz, resulting in 43,670 GAST-D epochs and an availability of 100 percent.
FIGURE 9. Normalized vertical Stanford plot of flight trials (GAST-D using GPS, GLONASS, and Galileo). Color scale indicates number of occurrences.
Of course, these results must not be misinterpreted as a multi-constellation GBAS performance assessment. The ground facility simulation was highly experimental and lacked any kind of long-term analysis. Even the GNSS antennas used do not meet formal requirements. However, aside from a quantitative judgment, these results show the practicability of this multi-constellation GBAS approach on an experimental basis.
Conclusion and Outlook
In this article, experimental extensions to GBAS have been developed to support GPS, GLONASS, and Galileo simultaneously. Based on these extensions, an optimized VDB transmission scheme has been created. In this way, the number of transmittable differential corrections could be maximized. Using flight trials, the multi-constellation GBAS concept has successfully been verified. The experimental airborne GBAS subsystem was able to calculate a valid GBAS solution including GPS, GLONASS, and Galileo satellites continuously.
It has been shown that multi-constellation GBAS is possible from a purely technical perspective. On the other hand, neither operational nor approval aspects for satellite navigation systems other than GPS have been addressed yet. Additionally, further testing would be necessary to ensure the compatibility with legacy GPS-only GBAS equipment. However, in theory, all modifications for Galileo are backward compatible. Nevertheless, it has to be assured that certified GBAS multi-mode receivers only use the GPS part of the VDB data and are not disturbed by additional VDB messages or additional ranging sources, for example. The required tests are planned for the future.
The operational benefit of multi-constellation GBAS systems cannot be foreseen yet. A certification for this will take several years and could only be addressed by the GBAS community after the completion of the GAST-D certification. Most probably, the use of GNSS signals on multiple frequencies could provide a highly improved GBAS service and will allow much more operational benefit. Many of the satellite navigation systems have already introduced additional frequencies, including signals in the protected L5 aviation band. The use of multiple frequencies for satellite navigation in aviation can remove most ionospheric errors effectively and mitigate a major source of uncertainty. Thus, multi-constellation GBAS can just be seen as a preliminary step on the way towards multi-frequency GBAS. The concepts and infrastructure described in this article will serve as a basis for more research in this area.
Acknowledgments
Most of our work on multi-constellation GBAS was done within the research project “Bürgernahes Flugzeug,” which was established in 2009 and is partly funded by the German federal state of Lower Saxony. This is gratefully acknowledged by the authors. Additionally, the authors would like to thank all colleagues involved for constructive discussions and their support. This article is based on the paper “Mulitple Satellite Navigation for the Ground Based Augmentation System” presented at ITM 2014, The Institute of Navigation 2014 International Technical Meeting, held in San Diego, California, January 27-29, 2014.
MIRKO STANISAK is a research assistant at the Institute of Flight Guidance (IFF) at the Technische Universität (TU) Braunschweig in Germany. He received his diploma in mechanical engineering (Dipl.-Ing.) in 2009 from TU Braunschweig.
MARK BITTER holds a Dipl.-Ing. in mechanical engineering from TU Braunschweig and has been employed as a research engineer at TU Braunschweig IFF since 2003.
THOMAS FEUERLE received his Dipl.-Ing. in mechanical engineering in 1997 from TU Braunschweig. He joined the TU Braunschweig IFF in May 1997. Since 2005, he has been the leader of the Air Traffic Management Team at the IFF. In April 2010, he completed his Ph.D. dissertation at TU Braunschweig.
FURTHER READING
• Authors’ Conference Paper
“Multiple Satellite Navigation Systems for the Ground Based Augmentation System,” by M. Stanisak, M. Bitter, and T. Feuerle in Proceedings of ITM 2014, the 2014 International Technical Meeting of The Institute of Navigation, San Diego, California, January 27–29, 2014, pp. 254–264.
• Standards Documents
Aeronautical Communications, Vol. 1, Radio Navigation Aids, Annex 10 to the Convention on International Civil Aviation, International Standards and Recommended Practices, International Civil Aviation Organization, Montreal, Draft Version, May 2010.
GNSS-Based Precision Approach Local Area Augmentation System (LAAS) Signal-In Space Interface Control Document (ICD), DO-246D, RTCA Special Committee 159, Global Positioning Systems, RTCA Inc. Washington, D.C., December 2008.
Minimum Operational Performance Standards for GPS Local Area Augmentation System Airborne Equipment, DO-253C, RTCA Special Committee 159, Global Positioning Systems, RTCA Inc. Washington, D.C., December 2008.
Minimum Operational Performance Specification for Global Navigation Satellite Ground Based Augmentation System Ground Equipment to Support Category I Operations, ED-114, EUROCAE Working Group 28 on Global Navigation Satellite System, European Organisation for Civil Aviation Equipment, Malakoff, France, September 2003.
• GBAS Research and Development
“Conception, Implementation and Validation of a GAST-D Capable Airborne Receiver Simulation” by M. Stanisak, R. Schork, M. Kujawska, T. Feuerle, and P. Hecker in Proceedings of ION GNSS 2012, the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation, Nashville, Tennessee, September 17–21, 2012, pp. 250–257.
“Initial GBAS Experiences in Europe” by A. Lipp, A. Quiles, M. Reche, W. Dunkel, and S. Grand-Perret in Proceedings of ION GNSS 2005, the 18th International Technical Meeting of the Satellite Division of The Institute of Navigation, Long Beach, California, September 13–16, 2005, pp. 2911–2922.
Supergeo Technologies, a global provider of GIS software and solutions, officially released SuperGIS Engine 3.2 to assists GIS developers in customizing GIS applications to meet diverse requirements of each project.
Developed by Supergeo through integrating mapping and GIS technologies, SuperGIS Engine 3.2, as the COM-structured development component, provides developers with complete GIS core components. The developed applications can be seamlessly embedded into programming language in Windows developing environment and integrated with other systems for strong system development, Supergeo said.
SuperGIS Engine 3.2 offers complete development resources. GIS programmers or developers are allowed to efficiently develop applications with GIS functionalities such as Display Layer, Edit, Query, Access Spatial Database, etc. Hundreds of GIS-related objects, diverse controls, comprehensive developing samples and object diagram are given to technical users, to effectively build programs and deploy to multiple end-users.
A variety of new components are contained in SuperGIS Engine 3.2. For example, “Internet Connection Component” for Proxy Server settings and “Data Exclusion” for excluding specified vector data for better map display are newly supported. In terms of mapping, point symbols can be rotated and resized according to their attributes for more flexible displaying effect.
Status map showing the location and density of volunteer submitted structure edits.
This April marks the one year anniversary of the transition of the USGS’s The National Map Corps (TNMCorps) from a small regional pilot project in the heart of Denver, Colorado, into a successful nationwide project. During the past year, civilian volunteers in every state have increasingly provided accurate mapping data to the National Geospatial Program’s publicly available application called The National Map.
Using crowdsourcing techniques, TNMCorps’ Volunteered Geographic Information (VGI) project engages citizen scientists to collect man-made structures data including schools, hospitals, post offices, police stations and other important public buildings.
Over the past year TNMCorps has achieved the following significant milestones:
1,422 – volunteers
42,009 – contributions (counts each person’s edit per single point)
50,696 – total number of edits (the sum of all edits made by volunteers)
50 – number of states involved
18 – number of volunteers who have earned more than 500 points
4,691 – state with largest number of edited points; Colorado
“This project has proven that we can count on volunteers to provide quality information to be included in authoritative government databases,” said Kari Craun, director of the National Geospatial Technical Operations Center. “The people that have contributed their time are performing a community service by ensuring key structures data are available publicly.”
To volunteer, go to The National Map Corpsproject site. The project is seeking anyone with access to the Internet willing to dedicate some time editing map data. Participants can earn badges and public recognition by a series of points.
While some familiarity with the area that a volunteer chooses is helpful, volunteers don’t have to live near a particular place to contribute. The tools on TNMCorps website, along with ancillary information available on the Internet, are generally sufficient to edit a distant area.
Trimble has announced the latest version of its eCognition software for geospatial data analysis. Trimble eCognition software is a powerful solution for the analysis and extraction of information from geospatial data collected via aerial, satellite and mobile mapping platforms, the company said.
The new version 9.0 release simplifies and reduces the time taken to classify objects in imagery data sets using the new template matching function. With eCognition 9, users can define objects graphically to streamline the template creation process. These templates are used to automatically identify objects of interest in imagery.
In addition, Remote Sensing and GIS professionals can now integrate data layers more efficiently through improved GIS tools within eCognition 9. These capabilities provide a framework for advanced analysis that allows professionals to use eCognition to resolve a larger range of geospatial queries and obtain more accurate results.
“With the fast growth of imaging and remote sensing data collection, geospatial professionals need faster and simpler methods to analyze and extract meaningful information from the data,” said Alain Samaha, business area director of Trimble’s Geospatial Software Solutions Division. “eCognition 9 takes simplification and integration to a new level while augmenting the precision and accuracy of results. This opens the door to a wider range of applications across multiple industries.”
In addition to the Suites enhancements, the Autodesk InfraWorks 360 family of offerings now includes enhanced roads and highways capabilities and new features to help civil engineers to model and visualize more realistic bridge design concepts.
“The architects, engineers, and contractors who use our products told us that they needed solutions to meet their real-world challenges, and we are responding. The 2015 Suites meet requests for greater productivity, improved collaboration, and more complete, better integrated BIM workflows,” said Amar Hanspal, senior vice president, IPG Product Group, Autodesk. “We also continue to offer more flexible ways to license our software, as well as more cloud services to improve customer collaboration and efficiency. Together with our customers, we are transforming the way buildings and infrastructure will be designed and built going forward.”
Here are the new features available in all of the 2015 Design Suites.
Productivity and design improvements including:
An updated, modern interface for Autodesk AutoCAD 2015 and AutoCAD 2015-based products: Helps building designers and civil engineers quickly open new and existing drawings with New Tab, visually access drawing content with Ribbon Galleries, and easily find tool locations with new Help Window functionality
Better integration with the cloud: New one-button access to Autodesk BIM 360 from Autodesk Navisworks Manage 2015, Autodesk Navisworks Simulate 2015, Autodesk Revit 2015, and Autodesk AutoCAD 2015 helps customers collaborate and manage their BIM project workflow and data
Enhanced point cloud capabilities include improved control over point cloud datasets and enhanced display settings in AutoCAD 2015-based products, as well as Autodesk Navisworks Manage 2015, Autodesk Navisworks Simulate 2015, Autodesk Revit 2015, Autodesk 3ds Max Design 2015, and Autodesk InfraWorks 2015, provide more realistic visualizations and walk-throughs
Building Design
Autodesk Revit 2015 software offers customer requested improvements to help make it easier for architects, and engineers to:
Apply a hand-sketched, graphic style to models, using the sketchy lines feature.
Include imagery in schedules to better convey graphical information.
Create and manage changes with improved tools to sketch and control revision cloud shapes.
Create more accurate documentation in 3D views using enhanced hidden lines capability.
New sketchy lines feature for Autodesk Revit 2015 software enables designers to apply a hand-sketched graphic style to views of a model to encourage client feedback and input when reviewing a design. Image courtesy of Autodesk.
A full rundown of additional 2015 enhancements for the Autodesk Building Design Suite can be found here.
“As we’ve grown, we’ve committed more and more to Autodesk Building Design Suite because it gives us the complete digital toolbox we need not just to complete projects, but to innovate as well. While Revit is our design workhorse, and we use Navisworks to coordinate building systems, we also use many other tools in the Suite as well as Autodesk 360 cloud services,” said Andrew Watkins, Associate Principal, Ayers Saint Gross, a top 300 global design firm according to ENR Magazine.
Civil Engineering
Autodesk AutoCAD Civil 3D 2015 software (included in various editions of the Autodesk Infrastructure Design Suite 2015) includes these improvements:
Greater flexibility for designing and displaying corridor models.
More efficient creation of profile layouts.
Better production drafting to create deliverables more efficiently.
More consistency between the AutoCAD Civil 3D and AutoCAD ribbon/command set.
Simpler ways to create custom subassemblies.
Streamlined geographic location functionality includes ability to capture and embed Online Map Data (such as aerial map information) for offline viewing and plotting.
Better interoperability and data exchange functionality for DWG and DGN files.
AutoCAD Civil 3D 2015 corridor modeling enhancements provide greater flexibility when designing and displaying corridor models.
Autodesk InfraWorks 2015 (which is included in various editions of the Autodesk Infrastructure Design Suite 2015 and Ultimate edition of the Autodesk Building Design Suite 2015) and Autodesk InfraWorks 360 (which offers additional cloud services that add collaboration and analysis for large-scale preliminary designs) offer new features and capabilities including:
An updated user interface for quicker access to the tool you need.
Support for additional data formats including AutoCAD 3D DWG, AutoCAD Civil 3D DWG, 3D DGN, IFC, and Sketchup (SKP).
CityGML import now supports schema location, building asset mapping, and self-intersecting geometry.
Autodesk InfraWorks 2015 and Autodesk InfraWorks 360 now offer a new, more intuitive user interface to help speed workflows.
Key updates for Roadway Design for InfraWorks 360 include style zones within road sections and fixed width parametric grading for roads with discrete control over grading, cut slope, and fill slope.
The new Bridge Design for InfraWorks 360 helps civil engineers explore preliminary bridge design options more effectively by modeling and visualizing realistic civil structures in the context of the surrounding proposed site. This new application helps simplify, accelerate, and focus the layout of girder bridge design concepts, and maintain consistent data and context.
Autodesk also released previews today for upcoming industry-specific applications for InfraWorks 360 including Drainage Design for InfraWorks 360 and cloud services including Model Builder for InfraWorks 360 and Corridor Optimization for InfraWorks 360.
Oil & GAS: Plant Design
Key customer requested enhancements to the Autodesk Plant Design Suite 2015 include:
Center of Gravity (COG) functionality to identify and edit COG for piping models, spools or components and produce COG reports.
Fixed-length pipe modeling capability helps route fixed-length piping more easily.
Bill of Materials capability to create tables and linked annotation when composing orthographic drawings.
New Center of Gravity functionality for AutoCAD Plant 3D 2015 software provides the ability to identify and edit center of gravity for piping models, spools or components.
Autodesk Building Design Suite 2015, Autodesk Infrastructure Design Suite 2015, Autodesk Plant Design Suite 2015 and Autodesk InfraWorks 360 availability and related cloud services vary by country. Details and purchasing options are available at www.autodesk.com/purchaseoptions, with subscription options outlined at www.autodesk.com/subscription/overview.
A new defense market report from Strategic Defence Intelligence has been released. “The Global Military GPS/GNSS Market 2013-2023 – SWOT Analysis: Market Profile“ provides readers with an exhaustive analysis of industry characteristics, determining the strengths, weaknesses, opportunities and threats faced by the Military GPS/GNSS market.
This SWOT analysis of military GPS/GNSS market is designed for industry executives and anyone looking to gain a better understanding of the market. It utilizes a wide range of primary and secondary sources, which are analyzed and presented in a consistent and easily accessible format. SDI strictly follows a standardized research methodology to ensure high levels of data quality and these characteristics guarantee a unique report, the company said.
The report provides these features to readers:
Quickly enhance your understanding of the global Military GPS/GNSS market.
Gain insight into the marketplace and a better understanding of internal and external factors which could impact the industry.
Obtain an overview of the global Military GPS/GNSS market, with examples being provided for each section.
Swedish WTS (Wonder Technology Solutions) and u-blox have announced that WTS has launched Trax, a personal tracking device for children and pets. Based on u-blox’ GNSS smart antenna and cellular module, the tiny tracker can be located anywhere, anytime via a free Android or iPhone mobile phone app.
In addition to real time tracking, Trax provides flexible geofence alerts, and can even monitor how fast your teenager is driving. It also works indoors thanks to a proprietary dead reckoning algorithm that delivers a position even when satellites are out of sight. Accurate down to 1.5 meters, the robust, water-resistant device also provides an “augmented reality” mode that helps users locate their trackers using a Smartphone’s built-in camera view.
To achieve the smallest possible size, Trax takes advantage of u-blox’ CAM-M8Q GNSS receiver module, which has a built-in antenna. CAM-M8Q (chip antenna module) provides both small size (9.6 x 14.0 x 1.95 mm) and multi-GNSS capability. It is based on a u-blox M8 chip and incorporates a chip antenna, SAW filter, LNA, TCXO and RTC crystal. The surface-mount module is also extremely low in height, making thin customer designs possible.
“Trax is the world’s smallest and most versatile personal tracking device available, packed with features designed to provide peace of mind to parents and pet owners almost anywhere in the world,” said Fredrik Danelius, managing director at WTS. “By combining the leading GNSS and cellular technologies from u‑blox, we have designed a tiny, reliable, low-cost device that protects our most valuable family members: children and pets.”
Trax comes with an integrated SIM-card and two years of free data and roaming in 33 countries. It is charged via USB and typically lasts between two and four days on a full battery. For wireless connectivity, the device contains u‑blox’ SARA-G3 GSM/GPRS module which is footprint compatible with u-blox’ 3G SARA-U2 module for easy 2G to 3G upgrade.
“Trax is an elegant and sophisticated example of our embedded GNSS and cellular modules combined to protect people’s loved ones”, said Pasi Alajoki, area sales manager at u-blox. “It is an important application of our mobile communications and global positioning technology where performance, size and power consumption play a critical role. We are proud WTS chose u-blox for Trax.”
