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In the world of precision GPS, Javad Ashjaee continues to push the industry ahead with new technologies and new options. With roots that date back to the early days of Trimble Navigation, Javad was integral to the creation of the first combined GPS/ GLONASS system. More than a decade ago he was part owner of Ashtech Precision. Next came a limited acquisition of Javad Navigation Systems by Topcon Positioning Systems, at which time Javad spurred the development of the first integrated RTK receiver, the HiPer system. His track record speaks for itself: rather than creating products that fit comfortably within market trends, he prefers to set new boundaries for those trends. He has done so with the help of dozens of talented and brilliant engineers who share a long history in the development of GNSS hardware and firmware.
With all of this in mind, it was with great anticipation that I waited for my opportunity to review Javad’s next generation of equipment under his new label: JAVAD GNSS.
In terms of appearance, the housings for JAVAD’s receivers and antennae look somewhat unearthlylike something from the X-files. In some ways, the units continue the philosophy behind the HiPer (also branded the JAVAD Navigation System Maxor). Similar in size and weight, the Triumph is a completely self-contained system. Everything needed to perform RTK, RTN and static surveying is sealed within the unit. UHF radios, memory, and batteries are contained inside the rugged, magnesium and plastic housing. Ingeniously, even the UHF antenna and GSM antenna are housed inside the "Green Stick" antenna, which is the green tube between the receiver and the pole. This configuration alleviates potentially snagging an exposed rubber duck antenna while threading through the brush and briars, and provides a very sturdy antenna connection.
Six eye-catching tri-color LEDs indicate just about everything a user could want to know about the receiver:
1. Power level of internal batteries: lights range from green (full), to yellow, to red (low).
2. Bluetooth connection: lights turn from red to green once a connection has been established. (Note: I appreciated the snappy, uncomplicated and reliable Bluetooth synchronization I experienced with these units.)
3. Modem link (radio or GSM): green = solid connection, yellow = "Can you hear me now!?", red = no connection.
4. Satellite count: green = eight or more, yellow = five to seven, red = less than five.
5. Position quality: green = fixed, yellow = float, red = autonomous. ( I liked this one, as it indicated in a flash when I went from `autonomous to float’ and `float to fixed’.)
6. Recording: green = recording is proceeding normally with a blink at every recorded epoch, yellow = memory will reach full in 10 minutes, red = memory full, and "off" = no recording is being done.
The unit is operated by only two buttonsthe power button and a function button, which are known as the MinPad interface. The unit I tested had five different ports. One was a power port for charging the two internal batteries or for using external power, two serial data ports, an Ethernet port and a USB port. Optional ports are available for an external antenna, an event-in and 1PPS (pulse per second) timing strobe for timing applications.
Memory is expandable to up to 2 gigabytes of static data storage, which by my rough calculations would provide almost six months of dual frequency GPS, plus GLONASS, raw data storage capacity at a 10-second interval. (Try sending that one to OPUS). Optionally, the user can have up to a 100-hertz update rate and RTK rate, carrier smoothing (for submeter applications), advanced multipath mitigation, in-band interference (for work near military installations and places where L-band signals are frequently tested), SBAS, and WiFi.
Buyers not intimately familiar with all of the many options offered by JAVAD GNSS may be initially overwhelmed by the wide range of products available to meet their needs. I’ve been involved with GPS for several years now and in some cases it is sometimes hard to distinguish between which options I really need and which would be an unnecessary extravagance.
The Triumph-1 has two different options regarding receiver boards, the G2T and the G3T. The G2T can receive GPS L1, L2, L2C and L5 as well as Galileo E1 and E5A and SBAS (such as WAAS and EGNOS). The G3T board adds GLONASS L1 and L2. 216 channels allow for the reception of the multiple frequencies currently existing and will also allow for expansion when other future GNSS systems become available.
Surprising Test Results
Using the system was almost addictive. Simple to set up and quick to get started, I found myself wanting to take the units out as much as possible. The first time I tested them at the Stumpwater R&D facility adjacent to our office, a very unusual result occurred. In gear-testing situations I typically store a point in the yard and then, leave the unit set up over the collected point, then prompt the data collector to stake out the point I just stored. I like to see the way the unit zigs and zags a few hundredths here and there as it directs me to the calculated coordinates. This unscientific exercise gives me some idea of how consistent the output position is and thereby the unit’s likely precision. Typically, with most every receiver I’ve used, the unit may move from the initial position three to five hundredths of a foot horizontally and will generally report a cut or fill of up to a tenth in just a matter of minutes. The Triumph, to my surprise, did not behave this way. At the most, I observed only a hundredth or two horizontally and about the same vertically. This motivated me to do an extended accuracy test a week or so later.
For this test, I set up the base over a known point and set the rover over another known point in the front yard of the office. The points were only separated by about sixty feet, so as to negate baseline distance. Over a period of approximately nine hours I recorded 311 epochs of fixed RTK data points. Bringing these points into a Microsoft Excel spreadsheet, my initial hunch was confirmed. The Triumph-1 is perhaps the most repeatable receiver I’ve tested yet. Averaging the 311 individual positions and then determining the difference between each individual epoch and the overall average, I was surprised by the very consistent results. Of the 311 positions, only 23 (7 percent) exceeded 0.033 foot (one centimeter) from the overall average, with none exceeding 0.067 foot (two centimeters) horizontally. Vertically, 79 of the 311 positions (25 percent) exceeded the 0.033 foot (one centimeter) threshold, and only six of those (2 percent) exceeded 0.067 foot (two centimeters). Horizontally this would indicate a one sigma error of about half of a centimeter, and vertically of just under one centimeter, which is phenomenal for RTK positioning and borders on post-processing static quality. Perhaps making this feat all the more impressive is that it was done with both GPS and GLONASS satellites.
Typically, GLONASS is regarded as an inferior signal to GPS for precise positioning due to its frequency modulation, which makes accurate wavelength determination tricky. In the wing-fold center insert of the July 2008 issue of The American Surveyor, Javad explains the methods used by various manufacturers to implement the GLONASS signal. Generally, GLONASS is only used for improving the time needed for an integer ambiguity fix and is then discarded. However, JAVAD GNSS has implemented a continuous GLONASS calibration tool in each receiver that removes a substantial amount of the biases in the GLONASS signal. I could easily see the fruition of their efforts in the very precise results of my own testing.
In the field, the units performed near flawlessly. I was only able to trick the receiver into displaying a false fix once while under some moderate pine canopy. Experience told me not to trust it as the receiver was working hard to generate a fix. Typically the receiver did a great job of not reporting bad fixed solutions while I pushed it into difficult canopy. The units were very functional in moderate canopy and occasionally functional under dense canopy, although, if I were working in timber a lot, I wouldn’t sell the total station just yet. The units proved to be just as accurate in the field as they were in testing, typically yielding results in clear areas with open skies in the centimeter or better range and around three centimeters (0.10 foot) in difficult canopy, assuming a fixed solution. I only experienced a couple of radio hiccups that required me to restart the base. These were sporadic and unexplainable, but a reset on the base seemed to correct the few occasions this occurred. Ultimately the units performed very well.
Physically, I liked the tactile texture of the unit, and the heft felt very solid, however, at nearly four pounds, I switched arms quite a bit as I walked from point to point. With the 182mm "Green Stick" antenna on the bottom of the unit, I found that I preferred an adjustable length pole over a fixed height pole for the rover. Using a fixed height, two-meter pole, together with the 0.182 meter antenna, the bottom of the rover was at nearly 7.2 feet, which garnered a lot of top-heavy leverage. If I were to buy the system, I would likely want a collapsible pole with a locking pin to prevent slippage. I could then set the unit at a more comfortable height with a lower center of gravity.
As a matter of preference, I like removable batteries as opposed to fixed internal batteries. That way if a battery becomes unusable, it can be disposed of and replaced by the user. Internal batteries require a trip to the shop when they wear out. You can do a field swap if onboard batteries start to run low. I did like the long run-time I observed with the JAVAD internal batteries. In testing, the batteries operated for more than thirteen hours in a constant RTK session. This would suffice for a very long field day or two normal work days.
Optionally, every receiver can perform as a base or a rover allowing you to switch them up at your discretion. Optionally, they can both be used as RTN rovers, doubling the output of your investment.
My contact at JAVAD GNSS, Michael Glutting, also sent me the Victor controller (manufactured for them by Juniper Systems). This unit had a demo version of Carlson SurvCE installed as well as a demo version of Tracy, JAVAD’s own data collection software. While the Victor worked fine controlling the Triumph-1, the limited functionality of the 30-point maximum file size led me to use a fully functioning Carlson Software Surveyor+, with SurvCE 2.0. I had at my disposal for the majority of the testing I performed. These two made for an excellent partnership and the Carlson software was able to control the Triumph in most any conceivable way.
Because the Tracy software is still somewhat in its infancy, I did not use it for this review, but I did investigate its features quite a bit in the office. As I handled the software, there were a few features that were noticeably absent in the version I was using, such as a differentiation between U.S. Survey Feet and International Feet. The software is on such a rapid development cycle that the latest version already addresses this need.
Conceptually, particularly for the price point, I believe it will be a great option for many users, particularly those who will only need GPS control. Some of the highlights I noticed were that the receiver status is continuously displayed, and of particular interest to me (and perhaps another first from JAVAD) is in-field post-processing to determine the quality of recorded raw data. The fact that the software is still a work-in-progress, of sorts, might be a concern for a potential buyer. But with the very reasonable cost of admission (a shade over $1800) and the fact that updates are free, Tracy starts to sound pretty good.
While I did not have the opportunity in this review to test the post-processed capabilities of the Triumph-1 raw data (outside of a couple of successful OPUS submissions) or the Justin postprocessing software, with the impressive precision displayed in the RTK tests, I would certainly enjoy the opportunity. Having said that, being a long time static enthusiast, I almost question the necessity of static post-processed methods given the incredibly precise RTK positions the system produced.
JAVAD and company have certainly raised the bar yet again with the Triumph-1 system. Solid, stable, functional and incredibly precise, I would encourage anyone who is looking for a new system to put a JAVAD next to the others you are evaluating and see if you don’t discover the same impressive results I did.
Shawn Billings is a licensed land surveyor in East Texas and works for Billings Surveying and Mapping Company, which was established in 1983 by his father, J. D. Billings. Together they perform surveys for boundary retracement, sewer and water infrastructure routes, and land development.
A 776Kb PDF of this article as it appeared in the magazine complete with images is available by clicking HERE