Is there a decimal place missing on the ad for the reach rtk receivers, or can you buy a multi constellation gnss rtk receiver for $799?
Am I missing or overlooking something here?
You're missing a frequency: the Reach units are L1-only. Not very useful for real-life survey-grade RTK.
Frame Surveying & Mapping
609 A Street
Davis, CA 95616
I know everyone has been bashing it for RTK survey use but with the extra constellations it has shouldnt that add up to something? I understand it doesn't have carrier phase since it's only L1 but my question has anyone on here actually put it to the test against their normal RTK setup.
I have one but haven't had the time to test it out yet been sitting on the desk for 2 months now, I did go out one night and pulled about 28 satellites.
Again its also convoluted a bit because its does not support state plane without use of an external controller with other software and my TSC2 quit connecting to my phone any more so I pretty much stopped trying to get it to work with the DC since then.
A sign of things to come?
I sold piles of Magellan Professional ProMark 3 RTK kits (Base/Rover) starting in October 2007 with a MSRP of under $10,000 with software. That was over 10 years ago. Compared with the performance/price of GPS L1+L2 the PM3 was an attractive alternative. However, compared to brand new multi-freq/multi-constellation systems, they don't work well at all.
As for the the $999 rover, the Emlid will connect to a network today with RTCM3. So there you go. No wait required.
I was looking at buying a pair to test, but I can't tell if the radios are FCC approved and I (of all people) am not in a position to import non-compliant devices into the USA. If anyone would like to buddy up, I am game.
While it is possible to construct a low cost rover today, RTK performance will be very unacceptable unless you are working in the salt flats west of Salt Lake City. However, there are plenty of companies out there who have plans to build low cost engines: SwiftNav, Sapcorda and others. When they crack the code, there may be some nice alternatives.
In the interim, you can be successful with current offering today. You have always been able to make money with RTK (and robotics too.)
ah, so that's it, missing more than a decimal place, missing a frequency.
Anyway, as Mark says, it does have potential for certain things. I paid a lot more than that for locus and promark single frequency receivers, and did a lot of good work with them. I continued to use single frequency for years with the impression that I couldn't afford a dual frequency rtk system, but they were actually cheaper than I realized.
Here is a company making survey grade GNSS for DJI Phantom 4 Pro drone.
The Loki Core is $5,395 and the Phantom 4 Pro Accessory Kit is $550.
- GPS L1, L2, L5 (enabled)
- GLONASS L1, L2, L3 (enabled)
- Support for Galileo, BeiDou, IRNSS, QZSS (optional)
- 448 Hardware Channels
- IONO+ advanced ionospheric correction
- APME+ multi-path mitigation
Reach has multi constellation, multi frequency cards listed at under a grand. Be very careful of the fine print.
L1 multi-constellation is very easy and affordable.
Now one must be very careful of the words multi-frequency. With L2C it is possible to build a cheap receiver that merely takes the L1C and L2C signals and mathematically merge them without cross-correlation and no analysis of the atmospheric conditions. The strength and value of survey grade receivers is in that fine tuning. Understand that that simple L1/L2 solution will be better than an L1 only solution and a second constellation also helps. There is another method that is improving precision and that is the using of the L1 correction signal from SBAS satellites to obtain additional ranging data from those SBAS satellites. SBAS ranging was first available in those ProMark 3s Mark Silver was selling, and is now being adopted in other receivers. SBAS ranging will improve further as more L5 satellites are put in orbit and then SBAS L5 corrections become available.
It is possible to make data appear better than it is by adopting strictly mathematical signal correlation and not use more complicated mathematical analysis of the signals. For instance I can take an L1 only RINEX file from my ProMark 2s and mathematically create L2 data and submit it to OPUS for solutions. That position solution however will be no better than if it were L1 only.
Also be aware that one of the most important features of a survey grade receiver is the survey grade antenna. These lower cost boards are prepared to use lower quality antennas and may not even be able to make the best use of a better antenna.
Paul in PA