Topcon Positioning Group said that its latest GNSS reference receiver, the NET-G5, is capable of tracking a new signal from the GLONASS constellation.
The GLONASS-M 55 satellite was launched in June 2014 and is equipped with the experimental payload capable of transmitting signals in the L3 frequency band. Engineers successfully tracked the signal with the NET-G5 receiver during a series of recent tests at the Topcon Technology Center in Moscow. The use of signals in L3 band alongside L1 and L2 bands is expected to further enhance the competitiveness of the GLONASS system.
“Topcon is committed to continually investing in research and development to offer end-users and the industry the most up-to-date solutions,” said Ivan Di Federico, chief strategy officer for Topcon Positioning Systems. “Our premier engineers, scientists and designers bring world’s first products and technologies to market, and the ability of the NET-G5 to track the latest signal — a first for the industry — is an excellent example of that dedication.”
Using Vanguard and Universal Tracking technologies, the NET-G5 receiver incorporates 452-channels capable of tracking the full GNSS signal spectrum, including modernized GPS, GLONASS, Galileo, BeiDou, QZSS and SBAS signals.
NTLab, a fabless microelectronic company based in Belarus, is offering the NT1051 dual-channel multi-frequency (L1/L2/L3/L5) mutli-system (GPS/GLONASS/Galileo/BeiDou) RF front end.
Manufactured in 0.18 um TSMC BiCMOS technology, it provides operability of the GNSS receiver even if interference power is 120-dB higher than the satellite signal.
The chip was designed to bring benefits of high-grade GNSS receivers to portable devices. To allow reliable navigation in the presence of interference, NT1051 has a 1-dB compression point (on RF input) of -40 dBm. This allows stable tracking, even if the interfering signal is 120-dB higher (compared to -160 dB of typical tracking sensitivity) than the satellite signal.
Simultaneously, portable devices require reduced power consumption. There is always a tradeoff between receiver linearity and consumed current, so the task of combining high dynamic range with low consumption was successfully solved in NT1051 architecture, NTLab said. The resulting power consumption is below 60 mW.
To allow dual-antenna receiver configurations, NT1051 has two separate channels with a common fractional frequency synthesizer.
Despite being an avowed Anglophile since my first visit to the United Kingdom, somewhere around 50+ years ago, I just could not help myself. Professor David Last, Professor Emeritus at the University of Wales (Bangor) and former president of the Royal Institute of Navigation (RIN) was holding forth, with that wonderful, attention-arresting public school accent, on weighty PNT (position, navigation and timing) matters before an awestruck audience.
Professor Emeritus David Last.
And what did I do? I just could not stop myself reminding him and everyone within earshot that the American Institute of Navigation (ION) predated the British Royal Institute of Navigation by more than two years. The point being, of course, that while two years actually makes little difference in the scheme of things, actuarially speaking we yanks rarely have the opportunity to make such a claim where our stiff upper-lipped Red Coat cousins are concerned. So, when the opportunity presents itself, as it typically does at ION GNSS+, then in my opinion, we former colonists just have to jump in with both feet — or one if by land and two if by sea, and all that.
An even more compelling argument for being first revolves around GPS versus Galileo operational satellites. The first GPS operational launch occurred in 1978, while Galileo has yet to launch a non-R&D operational PNT satellite, into a useable orbit that is. Now, before you accuse me of being smug, I am actually making a case for increased cooperation between the United States Air Force (USAF) and our European counterparts (ESA) where precision positioning, navigation and timing (PNT) schemes are concerned. For when it comes to satellite navigation and PNT, we yanks can definitely declare “been there, done that” mistakes and successes. What better place to “crow,” or rather, impart our considerable knowledge and network with fellow PNT aficionados, than at ION GNSS+.
ION GNSS+
All vocal eloquence jealousies and juvenile kidding aside, in many respects the ION GNSS+ event is actually the epitome of international cooperation in the PNT and GNSS (Global Navigation Satellite System) arena. This annual premiere event is described as “the world’s largest technical meeting and showcase of GNSS technology, products and services,” and I wholeheartedly agree. Indeed, the 2014 event, which took place from September 8-12 at the Tampa Convention Center in Tampa, Florida, had the stated goal of bringing together international leaders in GNSS and related positioning, navigation and timing fields to present new research, introduce new technologies, discuss current policy, demonstrate products and exchange ideas. It was a networking paradise in a wonderful, albeit somewhat steamy, venue, which you can review in two excellent videos concerning the event at the ION website.
This ION conference improves every year in content and attendance, and this year was no exception. Congratulations to Lisa Beaty and her whole team for a great conference, year after year. My favorite events are the annual GPS World Leadership Dinner and the prestigious annual ION Kepler award luncheon. Notice a trend?
GPS World Leadership Dinner
This much ballyhooed event becomes more and more of a draw each year. Tickets are coveted (as scare as hen’s teeth as Granny used to say) and competition is fierce. Every year we have about twice as many people wanting to attend as we have room to accommodate them. So the competition is never boring. This year was special in that one of our own GPS editors was nominated for an award and was overwhelmingly elected to receive it.
The Leadership Award winners this year were Javier Benedicto Ruiz, the Galileo Project Manager from the European Space Agency (ESA), who won in the Satellites category, while an old friend Sherman Lo, who is a senior research engineer and associate investigator (APNT) at Stanford University, won in the Signals category. Our own Eric Gakstatter, contributing editor for Survey and GIS from GPS World, won in the Services category; and finally Oliver Montenbruck, who is head of the GNSS Technology and Navigation Group, from DLR, the German Space Operations Center, won in the Products category.
GPS World 2014 Leadership Trophies.
The invited guests, and there was not an empty seat in the house, heard various perspectives from sponsors Lockheed Martin, Exelis, Raytheon, and Braxton Technologies, as well as visions of GNSS progress from our four award winners.
This event will be covered in much more depth in our December issue, but suffice it to say it was as usual a great event. I wonder from year to year how we will ever top the previous year’s entertainment, which always involves audience participation, but Alan Cameron just keeps coming up with outrageous ideas that seem to always pan out. Hope to see you there in Tampa next year.
The Kepler Award
This year, the highly prestigious ION Kepler Award was won by Dr. Pratap Misra. Even though I am happy to say that through the years many of my friends and colleagues have won this coveted award, I can honestly say, in my opinion, there has never been a more deserving award winner than Professor Pratap Misra.
[Correction: The newsletter summary of this article misspells Pratap Misra’s name. We apologize for the error.—Editors]
Pratap Misra, 2014 Kepler Award recipient.
I have had the good fortune to know Professor Misra for many years, and frankly erroneously assumed, along with many others, that since he is so obviously deserving he had previously won the Kepler Award.
The Kepler Award is presented annually by ION in recognition of an individual’s unparalleled, sustained and significant contributions to the development of satellite navigation. It is the highest honor bestowed by ION’s Satellite Division. Professor Pratap from Tufts University meets and exceeds all of these qualifiers and more. He is simply self-effacing and polite as he quietly goes about being the best in all he endeavors.
Throughout the years, I have found Pratap to be extremely dedicated to his work, and more recently to his students. These are key attributes. Academically, I can honestly say that the authoritative tome Global Positioning System: Signals, Measurements and Performance that he coauthored with, another friend and colleague, Professor Per Enge of Stanford University, is among the most dog-eared in my PNT library. This widely praised volume is often described as a “comprehensive introduction to GPS: the system, signals, receivers, measurements, and algorithms for estimation of position, velocity, and time.” And while it was originally intended as a textbook for senior or graduate-level engineering courses, it also serves remarkably well as a self-study guide for practicing engineers and as a reference tool for writers and researchers. I consider it to be one of the three PNT bibles that are a must-have in every PNT subject-matter expert’s (SME) library. (The other two are Global Positioning System: Theory and Applications, Volumes 1 and 2, by Bradford W. Parkinson and James J. Spilker, and Understanding GPS: Principles and Applications, Second Edition, by Elliott Kaplan and Christopher Hegarty.)
Revised Second Edition by Pratap Misra and Per Enge.
In recent years, Pratap Misra has been honored as both an ION and IEEE Fellow and has served as a past chairman of the ION Satellite Division. He has held numerous volunteer positions within ION, but most recently he has focused on something near and dear to his heart, the support of student programs. This is where Professor Pratap Misra is without peer. Frankly it is obvious that his students adore him, and it is due in no small part to his single-minded dedication to and concern for them.
Every time we meet, the majority of his words and thoughts concerns his students. Their welfare is always uppermost in his priority list. Inevitably, while we are attempting to conduct a quiet and private conversation or interview, we are constantly being interrupted by well-meaning students, past and present, who just want to thank Pratap for his help and support. I could fill up several pages with the technical accomplishments of Professor Pratap Misra, but none of those accomplishments, recognitions or awards mean as much to him as the love, support and success of his students. It is so obvious to anyone who pays attention that he wholeheartedly thinks of his students as and treats them just like family.
I am sure, or at least hope, we all have past professors or teachers in our lives that we remember fondly, and then there are the few or perhaps only the one that changed the course of our lives for the better. Professor Pratap Misra is one of those rare latter individuals, so deserving of the appellation — a professor that made a difference in the lives of his students. I am so proud that he deservedly won the Kepler Award and am deeply honored that I can call him my friend.
GPS-IRT Update
The Global Positioning System Independent Review Team (GPS-IRT) is now officially part of the Independent Strategic Assessment Group (ISAG) under the auspices of the Institute for Defense Analyses (IDA). For 19+ years, the GPS-IRT was a separate team within IDA that researched GPS matters with the “goal of insuring both the military and civilian communities would benefit from new GPS/PNT capabilities and services.”
As a result of this organizational change, Air Force Space Command (AFSPC) chose to formally recognize the GPS-IRT’s 19+ years of effort in support of GPS modernization.
Last Thursday, General John Hyten (USAF), the commander of Air Force Space Command, presented a commemorative plaque to Mr. Kirk Lewis, the executive director at IDA, for both the GPS-IRT and the ISAG. The plaque will be displayed with the GPS satellite on permanent display at AFSPC headquarters, in the James V. Hartinger building on Peterson Air Force Base, Colorado. The plaque contains the names of the four prestigious chairmen who led the GPS-IRT over the last 19 years, as well as the names of the members of the IRT over that same time period. Sadly, two of the chairmen and five of the members are no longer with us, but we can only hope they are looking down upon us fondly and giving us guidance of a different sort.
Until next time, happy navigating, and remember: GPS is brought to you courtesy of the United States Air Force.
OriginGPS has launched the Nano Spider, a tiny yet fully integrated GPS receiver. The Nano Spider module is designed to support ultra-compact applications where size is at a premium, such as smart watches, wearable devices, trackers and digital cameras.
OriginGPS, which previously introduced the Micro Spider (5.6 x 5.6 mm) module, said the Nano Spider is 47 percent smaller than its previous solutions, measuring 4 x 4 x 2.1 mm. The Nano Spider’s proprietary structure is a multi-level circuit for surface mounting, built to reduce footprint size.
“The wearable technology trend requires components that balance a small size with high-performance and best-in-class power consumption,” said Gal Jacobi, CEO of OriginGPS. “OriginGPS aims to continue to shrink the size of components, while increasing features to make adding location functionality possible for every device.”
OriginGPS’ Nano Spider continuously tracks all GPS satellites in view and provides real-time positioning data in the standard industry format defined by the U.S. National Marine Electronics Association (NMEA). The Nano Spider offers a complete System in Package (SiP) that includes:
Fully integrated features – The Nano Spider includes a low noise amplifier (LNA), surface acoustic wave (SAW) filter, temperature controlled crystal oscillator (TCXO) and real-time clock (RTC) crystal, a power management unit, and radio frequency (RF) shielding.
Superior sensitivity and performance – The Nano Spider module offers accuracy of approximately one meter, and achieves a rapid time to first fix of less than one second and tracking sensitivity of -163 dBm.
Continuous connectivity with minimal power consumption – It achieves a state of near continuous availability by detecting changes in context, temperature and satellite signals by maintaining and opportunistically updating its internal fine time, frequency, and satellite data, while consuming microwatts of battery power.
Improving marginal signal conditions – It includes OriginGPS’ proprietary Noise Free Zone (NFZ) system to increase noise immunity even under marginal signal conditions, such as urban canyons, under dense foliage or a rapidly changing receiver position.
To see a demo of the Nano Spider and Nano Hornet modules, visit OriginGPS’ booth (Hall A4 Booth 271) at Electronica 2014 in Munich, Germany.
A GPS tracking device helped Philadelphia police rescue a woman who was kidnapped November 2 and apprehend the suspect who abducted her. A growing number of used car dealerships use the technology to protect their investments. This time it protected the life of an innocent victim of violent crime.
Surveillance video showed the crime being committed. The brazen attack was shocking to watch — an innocent woman named Carlesha Freeland-Gaither was grabbed by a man who then forced her into a car parked at the curb. The man then got in the car and drove away.
Police investigating the crime immediately checked the surveillance video and discovered they could read the license number of the vehicle used by the kidnapper. When they checked the license number, they discovered the vehicle had been purchased from a used car dealership specializing in helping people with bad credit get car loans.
“‘Buy Here, Pay Here’ refers to the fact that the dealership is also serving as the lender,” said Eddie Bermudez, product development manager with Position Plus of Lake Forest, California. “These lenders take a big risk lending money to people who other lenders won’t touch.”
The BHPH industry found GPS tracking systems to be a big help when a borrower is delinquent on their loan payments. The Position Plus system is used by almost 1,500 dealerships across the country.
“The lender places a small GPS tracking device in the vehicle,” Bermudez said. “As long as their loan payments are current, there’s no problem. But if they go delinquent, the lender has the option of using the GPS tracking device to locate the vehicle. This makes the process of repossessing the vehicle much easier.”
The lenders each have a policy as to how they handle these situations. In most cases borrowers receive emails or text messages warning them they’re behind before repossession efforts are initiated.
Fortunately, the kidnapping in Philadelphia ended well. The vehicle was located in the parking lot of a shopping center. The suspect attempted to start the car, but he was completely surrounded by police. According to Bermudez, the PositionPlus system could have stopped him cold.
“If it had been our system, he wouldn’t have been able to start the car,” added Bermudez. “We can’t shut down the engine while it’s driving, but we can keep the vehicle from starting the next time the ignition is turned on.”
Telit Wireless Solutions has debuted the Jupiter SL871-S, designed for easy migration between a full-GNSS solution for top-ranked applications and a simple GPS-only solution for less demanding applications. The Jupiter SL871-S is designed to track and navigate GPS and QZSS constellations while ensuring pin-to-pin and protocol compatibility with its multi-constellation companion module, the SL871.
The module comes in a 9.7 x 10.1 millimeter LCC package with an ARM7 baseband processor, embedded ROM memory, and integrated LNA. It delivers geolocation data using NMEA protocol through a standard UART port. It supports ephemeris file injection (A-GPS) as well as Satellite Based Augmentation System (SBAS) for increased position accuracy.
In addition, its extremely low power consumption in all conditions is suited to applications requiring long battery life.
SL871-S has been designed to ensure hardware and software compatibility with SL871, allowing customers to design once and take advantage of the xL871 common form factor. Benefits include:
Pin-to-pin compatibility with SL871 family,
Same protocol used in SL871,
Straightforward migration between full-GNSS solutions and GPS-only solutions,
Satellite Based Augmentation System (SBAS) support for increased position accuracy, and
Assisted GPS.
The SL871-S can replace the SL871, allowing customers to design once and interchangeably mount the appropriate solution depending on the required features.
“The new SL871-S module designed to be easily swapped with other xL871 modules for enhanced simplicity and scalability,” said Taneli Tuurnala, CEO of Telit GNSS Solutions. “It is an ideal example of how buying a module from Telit enables our customers to avert the need to keep track of the latest chipset technology on their own. We keep them on top of the best available technology, pre-packaged in a module that is easy to replace as needed, without having to redesign their entire application to stay up to date.”
Farmers Edge, a precision agriculture and independent data management solutions company, has received an investment from Kleiner Perkins Caufield & Byers’ Green Growth Fund. With operations around the world, Farmers Edge provides a plug-and-play technology solution that helps farmers optimize crop inputs and maximize yield. The investment from Kleiner Perkins will fund expansion of Farmers Edge’s technology platform and support the company’s continued growth in international markets, Farmers Edge said.
“We see a huge market opportunity for Farmer’s Edge approach to precision agriculture. They uniquely integrate real-time satellite imagery and in-field telematics to maximize yield and minimize environmental footprint,”said Kleiner Perkins Partner, Brook Porter. “Farmer’s Edge is leading the current disruption around how crops are grown, and ultimately how crops are valued as traceability becomes an increasingly important factor in the food supply chain.”
On the heels of a recent acquisition, Farmers Edge has introduced FarmCommand, a comprehensive solution that provides farmers plug-and-play real-time equipment diagnostics and logistics telematics to any brand of equipment. FarmCommand will become part of the Precision Solutions product line that incorporates field-centric data such as drone and satellite imagery, soil testing, weather stations and precision agronomy. By coupling cloud-based software, Precision Solutions and FarmCommand, with an agnostic hardware solution, growers gain the ability to make comprehensive precision farm management decisions.
“We rely on Farmers Edge to function as an independent advisor, providing us with a no-hassle, turnkey solution to increase our profitability,” said Jerry Machacek, grower at Canora, SK. “They bring a level of hands-on service that is unique in the industry which is the reason we trust them with the management of our acres.”
“From seed selection to yield data analytics, we bring all the information together to make a meaningful impact on production and we stick by our customers to ensure the job gets done right,” said Wade Barnes, president and CEO of Farmers Edge. “We have an established history of partnering with both farmers and leading distributors to deliver products which will benefit the farmer and his trusted advisors.”
The new NEO-M8L Automotive Dead Reckoning (ADR) module by u-blox has integrated motion, direction and elevation sensors. The module integrates gyro and accelerometer with u‑blox’ GNSS platform u-blox M8 to achieve high indoor/outdoor positioning performance for road vehicle and high-accuracy navigation applications.
In addition to accessing the integrated module’s gyro and accelerometer data, accident reconstruction systems can provide the location of an accident to facilitate insurance claims even if a collision occurs in a tunnel or park house. High-end navigation devices are able to guide drivers through tunnels of several kilometers because of the accuracy of u-blox’ ADR system. Stolen vehicles can be located instantly due to continuous monitoring of sensor data and storage of location in non-volatile memory.
“Devices for usage-based insurance, stolen vehicle recovery, road pricing, fleet management, emergency services, and vehicle navigation depend on reliable, uninterrupted positioning including tunnels, park houses and stacked highways,” said Thomas Nigg, vice president of product strategy at u-blox. “The NEO-M8L is the ideal solution for all road vehicle based applications, able to calculate a position in all circumstances based on its own internal sensors, regardless of satellite visibility and end-device orientation.”
The NEO-M8L module will be demonstrated at the u-blox stand at electronica 2014 in Munich, November 11-14, Hall A4 Stand 219.
The compact module is 12.2 x 16.0 x 2.5 mm, requires minimum host integration resulting in no risk, is low cost, and provides fast time-to-market design, u-blox said. With uncritical orientation of the installed module, odometer function and autonomous data logging, it is an all-in-one solution for all road vehicle applications requiring reliable and uninterrupted position in challenging environments such as urban canyons, tunnels and underground parking.
The NEO-M8L embeds u-blox’ 3D Automotive Dead Reckoning (3D ADR) chip technology. Using the vehicle’s speed information and the module’s onboard sensors enables accurate positioning in three dimensions, even when satellite signals are completely lost and the end-device installation is not horizontal, u-blox said. An odometer function, based on the ADR technology, also provides accurate and continuous distance traveled.
The module is able to track all visible GNSS satellites including GPS, GLONASS, BeiDou, QZSS and all SBAS (European’s Galileo will be supported in a future firmware version). Concurrent reception of two GNSS systems is supported. The NEO-M8L module can output a position up to 20 times per second.
The module uses u‑blox’ M8 GNSS chip and is available in Professional Product grade. This grade includes qualification according to the ISO16750 standard “Road vehicles — Environmental conditions and testing for electrical and electronic equipment” and manufacturing in ISO/TS 16949 automotive-certified factories.
Samples and evaluation kits will be available in December 2014.
The Trimble Leap, also shown with a smartphone. Photo: Trimble
Trimble is making available the Trimble Leap, a Trimble RTX compatible GNSS Bluetooth device. When enabled with the ViewPoint RTX correction service, Leap delivers submeter accuracy directly to the Terrain Navigator Pro (TNP) Mobile app for iOS and Android devices. The TNP Mobile app allows users to collect markers, tracks and geo-stamped photos in the field, and then sync all the GNSS data into the Terrain Navigator Pro office software.
The TNP Mobile app enables users to:
Display and navigate routes created in TNP desktop.
Collect field data such as markers, tracks, photos, videos and audio clips.
Near real-time sync between phone and TNP map software via WiFi or cellular data connection.
View data on topo, aerial, and street maps downloaded to phone for offline use. Terrain Navigator Pro offers 1-meter aerial photos for the 48 contiguous United States. The seamless USGS topo graphic maps are based off 1:24K, 1:100K, 1:250K map scales. Alaska is 1:63K and 1:250K.
Access a compass and other geo-information such as lat/long, elevation, and direction on phone.
Collect data offline. The TNP mobile app uses the GPS built into the smartphones, so users can collect field data in areas without a cellular or data signal.
Trimble Leap is compact and portable, weighing 9.5 ounces. It snaps to a smartphone or tablet to use as a handheld, can be mounted on a monopole or tripod, or can be magnet mounted to a vehicle. Leap has 16 hours of battery life and uses Bluetooth communication to connect to smart devices for ease of use and flexibility. An onboard micro SD card stores the GNSS observables data for use in the field or the office.
A micro USB port can provide power to Trimble Leap for continuous fixed-mount applications, or it can be used with battery-booster products to extend field work. Trimble Leap is charged by a standard cell phone vehicle accessory charger, a USB connection to a PC, or from a USB AC adapter.
Based on Trimble RTX (Real Time eXtended) technology, ViewPoint RTX delivers better than 1 meter horizontal accuracy 95 percent of the time without the use of a traditional RTK base station or virtual reference station network. ViewPoint RTX is delivered into the TNP Mobile app via cellular data network and is available nearly anywhere in the world.
“Trimble Leap enhances the Terrain Navigator Pro solution by adding a simple way to collect submeter accurate geolocation data with standard Android or iOS devices. Adding accuracy to TNP’s robust field-to-office data collection solution provides a value-add where low-resolution collection is not sufficient. Trimble Leap with TNP Mobile is configured and operational in minutes with little training,” said Larry Fox, business area manager for Terrain Navigator Pro.
Terrain Navigator Pro integrates powerful desktop mapping software, a cloud connected mobile data collection platform (compatible with GPS-enabled iOS and Android devices) and a robust Web portal. TNP users can plan projects in the office, collect data in the field and access projects from the Web—simultaneously. Geo-referenced data such as tracks, waypoints, photographs and video can be shared, updated in near real-time and displayed on the included topographic, aerial/satellite or street base maps.
Swiss-based u‑blox has introduced the EVA‑M8M stand-alone positioning module. The EVA-M8M GNSS module brings concurrent multi-GNSS performance into the ultra-compact EVA footprint.
Designed for cost- and space-sensitive applications, the highly integrated 7 x 7 x 1.1 mm LGA module comprises all necessary components, including crystal and passives. EVA-M8M only requires an external antenna to provide an accurate position without the need for host integration. Components have been selected for reliable operation in the field over the full operating temperature range. The module is also compatible with the EVA-7M GPS module, allowing for easy upgrading of existing designs at minimal cost, u-blox said.
The module supports GPS, GLONASS, BeiDou, QZSS, and SBAS augmentation systems. Based on u‑blox M8 performance, the module achieves -164 dBm tracking sensitivity, fast acquisition time and low power consumption. EVA-M8M can track any two GNSS systems simultaneously and output a GNSS position up to 18 Hz.
“The EVA-M8M sets a new industry benchmark for compact, stand-alone global positioning performance. The module has been designed for the absolute lowest eBOM costs and ease-of-manufacturing. It is a perfect solution for cost-sensitive industrial and wearable devices,” said Thomas Nigg, vice president of product strategy at u-blox.
A UART, USB, SPI and I2C interface provide flexible connections to a host processor. EVA-M8M can also communicate directly with u‑blox’ SARA 2G, LISA 3G and TOBY 4G cellular modules to support advanced tracking and location-aware products.
Detailed information about the EVA-M8M can be found on the u-blox website. Samples are available now. For existing designs using a NEO module, the C88-M8M adaptor board can be used for easy evaluation of the EVA-M8M in existing NEO-xM designs.
A single-feed smart antenna (left) compared to the multipath rejection results of the new TW5340 smart antenna with Accutenna technology. Photo: Tallysman
Tallysman’s new TW5340 smart antenna is designed to pair Tallysman‘s Accutenna technology antenna with STMicroelectronics’ Teseo II receiver. The combination makes the smart antenna accurate for use in all environments, including urban canyons, according to the company.
The TW5340 is a multi-constellation GNSS Smart Antenna that provides simultaneous GPS/GLONASS/SBAS reception. It is designed for use in professional-grade applications such as precision timing, network synchronization, low current applications, and tracking/positioning applications.
To illustrate the advantages of this technology coupling, simultaneous recordings of vehicle position were conducted using two smart antennas — one with and one without Tallysman’s Accutenna technology — in an area of downtown Ottawa, Canada, notorious for high levels of multipath signals. Results show how the high multipath signal rejection capabilities of Tallysman’s Accutenna technology greatly improves accuracy, the company said.
The Tallysman TW5340 smart antenna.
The TW5340 supports STMicroelectronics Autonomous A-GPS, which accelerates GPS positioning by predicting satellite ephemeris data based on previous observations. This results in extremely fast time-to-first-fix. The TW5340 can be configured to output up to three NMEA 0183 message lists with navigation update rates up to 10 Hz. RS232, CMOS, and USB interfaces are available with input voltage options of 3,3V, 5.0V, and 12V. A standby-mode feature provides for very low current consumption (<100uA) and is particularly useful in battery-operated applications.
A standard one pulse-per-second 1PPS synchronized to UTC time is available as a single ended output or as a differential output at RS422 levels.
Tallysman’s Windows-based Configurator enables simple configuration of parameters such a baud rates, output message rates, constellation, tracking parameters, 1 PPS configuration and standby-mode parameters.
The TW5340 is housed in an IP67 housing and is REACH and ROHS compliant. A non-magnetic version is also available as Part Number TW5341.
The 2014 Trimble Dimensions User Conference is being held in Las Vegas this week. Photo: Trimble
With more than 4,000 attendees, this year’s Trimble Dimensions User Conference was the largest ever and, I must say, a well-organized event chock full of technical content — enough to squelch the most intense geospatial hunger pangs you might have.
One could write a book on all the technology and market segments that Trimble is pursuing and offering solutions for. In addition to a wide range of GNSS, geospatial, construction, control, and data management systems previously offered, Trimble boasted a USB stick full of press releases with new product and service announced at Dimensions. So, the challenge is deciding what to write about without writing a little bit about everything.
After my first day at Dimensions, it became clear to me what I needed to do. Among the many product and service announcements was a new GNSS correction service named Viewpoint RTX. While I’ve tried to stay up to speed on Trimble’s various GNSS real-time correction services, this one was the straw that broke the camel’s back for me. I decided I needed to get a solid grip on the range of real-time GNSS correction services that Trimble offers because the picture was getting fuzzier, at least to me, with each new real-time correction service introduced. It used to be pretty simple to decipher; not so much any longer. So I had a conversation with Patty Boothe, general manager of Positioning Services at Trimble. Patty, a 15-year Trimble veteran, was appointed GM of the newly formed group three years ago. Here’s the low-down on the services.
Remember, Trimble acquired the land portion of OmniSTAR’s business a few years ago. For years, OmniSTAR has been one of the two dominant commercial satellite-based, real-time GNSS correction services (the other being John Deere’s Starfire service, as well as new entrant Terrastar). The OmniSTAR acquisition was Trimble’s entry into the satellite-based, real-time GNSS correction services business. Since then, Trimble has introduced the RTX (not to be confused with RTK) range of GNSS correction services. You might say that OmniSTAR and RTX are competitive services within Trimble. They are, to a certain extent, and I’ll attempt to clarify that below.
Following is a list of Trimble’s real-time GNSS correction services, starting with the OmniSTAR services:
OmniSTAR VBS: Satellite-based, real-time submeter service. The VBS service has been made obsolete largely by free public satellite-based augmentation systems (SBAS) such as WAAS/EGNOS/MSAS/GAGAN/SDCM. It is still used in geographic regions where free public SBAS don’t exist, primarily South America, Central and Southern Africa, and Australia. GPS-only service. Requires single-frequency receiver (L1).
OmniSTAR XP: Satellite-based, real-time 15-cm service based on Jet Propulsion Lab (JPL) technology and delivered to users on the ground via OmniSTAR’s geosynchronous satellite network. GPS-only service. Requires dual frequency (L1 and L2).
OmniSTAR HP: Satellite-based, real-time 10-cm service based on OmniSTAR’s reference station network and delivered to users on the ground via OmniSTAR’s geosynchronous satellite network. GPS-only service. Requires dual frequency (L1 and L2).
OmniSTAR G2: Satellite-based, real-time 10-cm service based on Jet Propulsion Lab (JPL) technology and delivered to users on the ground via OmniSTAR’s geosynchronous satellite network. GPS+GLONASS service. Requires dual frequency, dual constellation (L1 and L2).
To use OmniSTAR services, one must have an OmniSTAR-enabled GNSS receiver. There are a several receiver manufacturers that support OmniSTAR GNSS correction services, such as NovAtel and Hemisphere GNSS, in addition to Trimble.
After, or at nearly the same time, Trimble acquired OmniSTAR, the company launched its RTX GNSS correction service. RTX’s infrastructure consists of ~110 GNSS reference stations around the world working to create high-precision corrections on a near global scale. The first significant differentiator is that Trimble RTX services are only offered on Trimble GNSS receivers, so you’ve got to be “all in” with Trimble to utilize RTX.
Viewpoint RTX: Internet-based (notice I didn’t write satellite-based), real-time submeter service. This is a new service introduced this week at Dimensions for the new Leap GNSS receiver and the Geo7 GNSS handheld. GPS+GLONASS service. Requires single-frequency receiver (L1).
The above are the three RTX services. There are some options for the above, but let’s talk about satellite-based GNSS correction services for a minute.
The advantage of satellite correction services is that, because GNSS corrections are delivered via satellite, your receiver doesn’t need to be connected to the Internet or have any other sort of terrestrial radio communications to receive data from the GNSS reference station(s). Because delivery is by satellite, you could be in the middle of a desert with no mobile phone coverage within 100 km, and you could still use OmniSTAR or RTX services. The only requirement is that your receiver needs to have direct, continuous line-of-sight to the OmniSTAR/RTX geosynchronous satellite (both services use the same geosynchronous satellites to broadcast the corrections).
The primary disadvantage of OmniStar and RTX services is the “convergence” time required to achieve the stated accuracy service levels. With the exception of OmniSTAR VBS (sub-meter), Viewpoint RTX (sub-meter) and Rangepoint RTX (50-cm) services, the OmniSTAR and RTX centimeter and decimeter services require tens of minutes of initialization time to converge to the stated accuracy. For example, if you want to use the 4-cm Centerpoint RTX service, you may have wait up to 30 minutes for it to converge to 4-cm accuracy.
Now, there are a couple of ways to reduce the convergence time:
Start on a known point. For example, if you’re using Centerpoint RTX on a tractor for planting and you shut down for the evening, you can start it up the next morning (assuming you didn’t move the tractor), and it will converge nearly immediately.
Trimble offers a fast convergence option ($) in some geographic areas where it augments RTX with local RTK reference stations. Currently, Trimble offers this service in five U.S. “corn belt” states.
For OmniStar XP, HP and G2 services, the only way to reduce convergence time is number one above, start on a known point.
It’s important to note that all of the centimeter and decimenter satellite-based services described above are based on real-time Precise Point Positioning (PPP) technology, which is different than RTK technology. The fundamental difference is that real-time PPP technology relies on a global, distributed network of reference stations. For example, Trimble has ~110 reference stations to cover the globe (mostly) with its RTX service. On the other hand, RTK requires a much more dense network of GNSS reference stations. For example, in Washington State there are ~100 GNSS reference stations that comprise the state-wide RTK network.
Lastly, Trimble offers a hybird RTK/RTX service called XFill. The idea is that for RTK users who lose communications to their RTK base or RTK network can use the Centerpoint RTX as a “seamless” back-up, maintaining RTK-level accuracy (1-2cm) for the first five minutes of RTX service, and then degrading to Centerpoint RTX accuracy after 20 minutes. Trimble reports there is no convergence time when transitioning from RTK to RTX, like you would if you were starting RTX right away. Standard XFill is included with certain Trimble RTK receivers and allows up to five minutes of RTX satellite time. Last month at the INTERGEO conference, Trimble introduced Expanded XFill which is a subscription service for those users who want more than five minutes of RTX time. For those users, Patty said that users can buy blocks of RTX time starting at 10 hours.
So, you might ask how Trimble handles the horizontal datum differences between RTK and RTX since they are likely not referenced to the same horizontal datum. For example, in the US, Trimble VRS RTK infrastructure is typically referenced to NAD83/2011 while Trimble RTX is referenced to ITRF08. There’s about 1 meter difference between the two. After finding the correct Trimble person, he said that Trimble does a 3-parameter local shift (dX, dY, dZ) on the fly when in RTK mode so that when there’s a transition from RTK to RTX, the horizontal datum difference is already resolved.
A by-product of Trimble’s ~110 global GNSS reference station network is a real-time, world-wide TEC (Total Electron Content) map. Since real-time PPP GNSS correction services (and public SBAS like WAAS/EGNOS/MSAS/GAGAN) rely on accurate models of the TEC in the ionosphere to account for the GNSS measurement delay, real-time TEC maps give users an indication of how the ionosphere’s TEC is behaving. This sort of map is particularly useful in attempting to predict the understand single frequency receivers using services such as public SBAS, OmniStar VBS, and Viewpoint RTX. The next time you here about an impending solar storm, take a look a the map using this link and see the TEC hotspots around the globe. Notice the more intense activity near the geomagnetic equator.
TEC map from Trimble’s ~110 global GNSS receivers. Photo: Trimble
Shifting gears slightly, at the conference, Trimble also introduced a new mobile phone GNSS add-in product called Leap, which uses the Viewpoint RTX service.
Trimble Leap GNSS Receiver with a Samsung Galaxy Phone. Photo: Trimble
