The use of the Satellite Based Augmentation System (SBAS) for GPS real-time corrections has become common as the coverage and reliability of the system have been validated. For background on SBAS (WAAS, EGNOS, MSAS, etc) or Omnistar Service, please see “Understanding SBAS”.
All GPS receivers sold on the market today are normally SBAS compatible. But the SXBlue GPS is specifically designed to be the highest performing GPS/SBAS system in the GIS/Mapping industry, and at a breakthrough price point.
What makes the difference? What is unique about the SXBlue GPS?
The SXBlue series use SBAS to full potential and as the only needed source of differential correction for an all-day DGPS operation. We invite you to read more about these key advantages:
A Submeter Solution without Post-Processing
Why doesn’t the SXBlue require any post-processing?
The strength of the SXBlue GPS series is its ability to maintain DGPS positioning when the SBAS (WAAS, EGNOS, MSAS, and compatible or Omnistar) signal is obstructed by all sorts of canopy. SBAS signals are the same nature/frequency range as GPS signals (this is why the same GPS antenna receives both GPS signals and SBAS corrections), therefore, subject to the same type of obstructions. The problem is very simple: when there is no differential correction signal, there can be no DGPS… However, the SXBlue GPS is able to maintain submeter accuracy for the next 40 minutes after the loss of the differential correction source signal.
The SXBlue is not simply raising the age limit of the differential correction input, but it anticipates and predicts, through sophisticated, patented and field-proven algorithms, how the ionospheric conditions, GPS clock and ephemeris evolve with time. This proprietary technology ensures that you will never have to spend time post-processing again!
Furthermore, the SXBlue not only offers two dedicated, high sensitivity, SBAS channels but also uses these geostationary SBAS satellites for ranging in the position computation (think of it as extra GPS satellites).
With the SXBlue you are set to Go Realtime all the time !
Will this technology also work in forestry applications?
Absolutely and this is the feature that has built the reputation of the SXBlue GPS on top of its superior tracking under trees. You will not get submeter under forest canopy but will get an all-day DGPS solution without the need to ever post-process. The SXBlue GPS, with this enhanced realtime capability, has proven to be, if not better, at least equivalent to any post-processed receiver on the market today. Not only evaluated by independent third parties, but also challenged on the toughest US Forest Service GPS test courses.
You are invited to read a few Testimonials from some of our forestry customers under the “Home” menu.
The SXBlue GPS… It works where you work !
Will this technology work with an external source of differential correction?
Is submeter post-processing more accurate than realtime?
Not in the case of the SX Blue GPS. For regular GIS submeter mapping work, using carrier phase smoothing, the realtime SBAS accuracy of the SXBlue GPS will be equivalent or even better than the best post-processed receivers on the market.
For multipath free environments, carrier phase float and fixed post-processing methods will yield 15cm to sub-cm accuracy respectively. In these cases the methods of data collection are different than submeter and require initialization time or longer observation time and specific L1 carrier phase software for the post-processing. For such solutions, please link to our “High Accuracy Solutions” menu to see what we offer.
Unmatched Accuracy and Performance with SBAS
Because professionals need positioning that they can count on, Geneq has developed the SXBlue GPS series to obtain 60cm accuracy (that is 2 feet) using free WAAS, EGNOS, MSAS, and compatible SBAS signals, as well as Omnistar subscription service (with the SXBlue II-L receiver).
This 60cm accuracy is specified in 2dRMS, which means 95% confidence.
In HRMS or simply RMS (Root Mean Square, 67% confidence), this is equivalent to 30cm RMS (that’s 1 foot).
In CEP (Circular Error Probable, 50% confidence), then the SXBlue GPS accuracy is 25cm CEP.
And yes… using SBAS signals alone!
Still not convinced, then give us a call or write to us and we will put you in contact with your nearest dealer for further application assistance.
Is SBAS that accurate and reliable?
SBAS is quite accurate (for example, see the latest WAAS performance report http://www.nstb.tc.faa.gov/ from the Federal Aviation Administration Technical Center) but what makes your position accurate is how the SXBlue handles and processes the SBAS signal. The SXBlue GPS receivers have been designed to handle SBAS signals to full potential, as the only needed source of differential correction, in very unique and innovative ways not only to achieve this accuracy, but to also provide full day operation in DGPS.
How reliable is SBAS? WAAS, EGNOS, MSAS (and compatible) were designed primarily for aviation use where precision approach/landing is the goal. In simple words, in an aircraft, our lives will depend on these SBAS signals. The integrity that such SBAS systems offer is higher than any other source of differential correction in the world.
Where can I get this accuracy using the SXBlue GPS series?
Free SBAS (WAAS, EGNOS, MSAS and GAGAN) constellations are spreading globally. In order to use the free SBAS signals two conditions must be met:
1- be able to view at least one of the geostationary SBAS satellites and
2- be within the broadcast ionospheric coverage map.
(All the ionospheric grids below were collected with SXBlue GPS receivers. The Indian GAGAN grid was recorded when the signal was being transmitted by Inmarsat 4f1.)
Unlike LBAS (Local Based Augmentation System) you do not need to be close to an SBAS ground monitoring station to get this accuracy. Refer to “SBAS Made Easy” to understand the differences between LBAS and SBAS.
The SXBlue has the unique ability to further extrapolate the received ionospheric map, thus expanding the coverage area of an SBAS constellation. This is very useful in countries/places where SBAS coverage is marginal.
What occupation time is required to obtain submeter accuracy with the SXBlue?
Just follow this minimal guideline:
- After powering on the receiver, let it track for 3-5 minutes. The receiver will download the ionospheric map from the SBAS satellite and transition from the GPS iono map to the more accurate SBAS map. This time will also allow carrier phase smoothing to kick-in. Every fix collected in multipath free environment will be submeter.
- After coming out of a high multipath or obstructed environment, just wait about 15-20 seconds before collecting a point.
What if there is no free SBAS coverage in my area?
For areas where no free SBAS coverage is available, the SXBlue II-L GPS, with support for the worldwide Omnistar VBS differential correction service, is your best solution. Visit http://www.omnistar.com/coveragemaps.html for the coverage maps.
Other realtime options are also available for our receivers and can be purchased and field-activated. These include:
- The Auto-Dif feature. This feature provides with two modes.
– The first is a base station-free rover. You set your SXBlue on a known point in the field, send the coordinates to the receiver to initialize it (in simple words the rover will act as a base station for a fraction of a second) and for the next 40 minutes you will be submeter relative to the initialization/reference point. After this 40 minute period, you will need to initialize again either on the same reference point or another one.
– The second mode of operation is a standard base station with RTCM output. In this case the receiver remains on the reference point and broadcasts standard correction and a second SXBlue GPS is used as a rover with a communication link in between.
- Higher accuracy local differential as above but for sub-foot (float) or cm-level RTK (see “Options for Higher Accuracy” bellow).
A Modular System
Who said a “two-piece” GPS mapping system is better than an all-in-one solution?
The SXBlue GPS did and the market is proving it right…
When Geneq launched the world’s first submeter Bluetooth receiver on the market back in 2003, users were freed from the constraints and costs of integrated GPS systems. For the first time, users could build their own GPS data collection system based on specific needs, requirements and budget.
A flexible modular GPS allows you to adapt to rapidly changing data collection platforms. Field data computers have evolved as fast as desktop PC’s with the same advantages and issues. We have seen Pocket PC 2000, 2002, Windows Mobile 2003, 5.0, 6.0 and yet more revisions to come; not mentioning all the Windows CE.Net versions with their known limitations. On the processor side, most PDA’s are up to the 800MHz range offering gigabytes of Memory/storage instead of the initial megabytes. We have seen new software no longer supporting older operating systems/processors and yes, we have seen customers stuck with old, obsolete all-integrated technologies worth thousands of dollars and no longer usable with new software.
The SXBlue GPS… A protection to your long term investment !
The old days of proprietary operating systems and field data collection and post-processing software are now over with the SXBlue GPS series. Therefore what most people see, unfortunately, as an advantage in an all-integrated GPS receiver is indeed a huge disadvantage, limiting the total investment to at most, a couple of years. In fact, the only advantage might be in body-building… bigger biceps and triceps for the field crew!
Will the SXBlue be compatible with my computer or data collection software?
The answer is yes.
Using Bluetooth technology, now widely used as a cable-free link, the SXBlue outputs standard NMEA data messages to reach directly the software of your choice installed on any PDA, Laptop, Tablet PC or the latest UMPC’s (Ultra Mobile PC, 5″ to 7″ screens running Windows XP or Vista).
Along with the Bluetooth port, all SXBlue GPS receivers feature a serial port. A USB port is also available on the SXBlue II and II-L models.
Build your own GPS data collection system and set yourself free !
Options for Higher Accuracy
When better than sub-20cm or cm-level is required, higher accuracy options are available in either realtime or post-processing methods.
Both methods require an LBAS configuration (base/rover within a certain range of each other) for either fixed or float solutions.
We invite you to visit the Introduction of the “High Accuracy Solutions” menu for more information on available configurations.
Low Cost Purchase and Operation
The SXBlue GPS is available at an unheard of price point for a professional submeter GPS solution. Additional economic benefits include:
- Lower cost to own: no extra post-processing software required for realtime submeter work.
- Lowest cost of operation: eliminate hours/year spent post-processing and expensive post-processing yearly software maintenance
- Freedom to choose your own off-the-shelf field data collection software with no requirements for special add-ons
- The benefits of realtime DGPS in the field: navigating, or locating/finding buried assets under snow, or for true mobile/server applications
- Direct linkage to your existing GIS/CAD system and workflows.
Feel free to call us or write to us.
10700 Secant Street, Montreal, (Quebec), H1J 1S5
Tel: (514) 354-2511
Toll Free (North America Only): 1-800-463-4363