Hi SparkFun Team I work at Land and Water Science in New Zealand. We Operate a Medusa MS700 Radiometric Sensor for soil mapping. It currently uses a standard gps antenna with SMA Connection. Its Accuracy and reliability in the field having been creating unwanted problems. A friend of mine recommended your Facet RTX unit as a possible solution. I have done some reading and watched your informative videos. The Radiometric Sensor requires GPS / GNSS Signal via SMA connection. What do you recommend? We need sub 0.5M Accuracy Do we need a base station unit as well? A New SBAS correction service has just become available here in New Zealand & Australia that would help achieve 10cm Accuracy. Kind Regards Tim Campbell
The facet doesn’t use an SMA, it has an internal antenna
I think this might be a list of what you’re after:
https://www.sparkfun.com/products/18443 RTK surveyor
https://www.sparkfun.com/products/21801 Antenna
https://www.sparkfun.com/products/21223 Splitter
Run through the guide https://learn.sparkfun.com/tutorials/sp … okup-guide and the manual https://docs.sparkfun.com/SparkFun_RTK_Firmware/intro/ which will clarify a lot of the product’s use.
The Radiometric Sensor requires GPS / GNSS Signal via SMA connection.
The location precision of your Radiometric Sensor is dependent on two things: the accuracy of your receiver and how good your antenna reception is. We can’t change the receiver inside of the Radiometric Sensor so all we can really do is give you the best antenna. My recommendation is the SPK6618H (https://www.sparkfun.com/products/21801). I suspect (but I couldn’t find any info in the Radiometric Sensor info sheet to support this) the receiver inside your sensor is L1 band only. Even the best antennas will only give an L1 receiver about ~1m accuracy. Probably not what you’re looking for.
Now if you’re talking about walking around with the Radiometric Sensor along side one of our RTK products on a surveyor’s pole, our RTK products will happily mark the location on a map where you took a reading with the Radiometric Sensor (maybe you’re writing the RS reading down or … ?). Our RTK Facet, Express, Surveyor, etc will all achieve ~0.3m accuracy off the shelf and with an RTCM feed you’ll get centimeter level accuracy. How you correlate these XYZ locations from the RTK device to where your RS sensor is located would be up to you.
I’m not sure about the SBAS signal in AU/NZ but all my experience with SBAS in North America is that it helps get from ~5m to ~1.5m accuracy, but not much lower than that.
Regarding SouthPAN (Southern Positioning Augmentation Network), can we expect it to “just work” out of the box?
Please see https://www.ga.gov.au/scientific-topics … m/southpan
For example with RTK Surveyor in positioning mode (ie no base station /no RTK corrections)?
thanks … Jason
It’s complicated.
https://www.ga.gov.au/__data/assets/pdf … users-.pdf
https://www.ga.gov.au/__data/assets/pdf … SDD-OS.pdf
I doesn’t look like SouthPAN will ever provide the level of corrections for RTK. Instead, it’s an SBAS system. The claims of 0.10m resolution are also a bit dubious. The docs above show 0.4m with 80 minute convergence time.
I don’t believe the ZED-F9x series supports the ability to decipher the SouthPAN SBAS signal but u-blox is fairly rigorous about supporting signals on new satellite networks. So perhaps, in the future, there would be a firmware release for the ZED that allows SouthPAN to be supported. Unfortunately half of the SouthPAN system is based on L5 reception with the ZED-F9x does not support (L1/L2 only with L1/L5 only available for ZED-F9T timing applications).
Hi Sparky, thanks for this. I see someone else has a product based on the ZED-F9P where they claim SouthPAN support: https://www.ardusimple.com/product/rtk- … veyor-kit/
Does this suggest u-blox has already released the firmware? If so, when might RTK Surveyor be able to use it in positioning mode? 
From our u-blox FAE:
The SouthPAN L1 SBAS signals will be detected and used like any other SBAS signal. If enabled the customer could monitor UBX-NAV-SBAS to see that the corrections are being applied.
The L5 OS-DFMC is not currently supported, and not on the current roadmap.
So yes it does sound like SBAS will aid out of the box. But, perhaps I’m pessimistic today, I don’t suspect the SouthPAN signals to help much. Everything I’ve read, these signals are not to aid with RTK calculations, only SBAS. However, I would love for someone to prove me wrong.