I’ve read all the guides and watched the videos and I’m trying to put together a list of all the items I need to perform RTK. I work for a small engineering firm and having a more accurate gps system would be very helpful especially for GIS tasks. I’d like to have a system that can work independently of cell service. What do I need to do this? Right now, I’m thinking of getting 2 Facet kits, the Holybro telemetry antenna set, ground plate, tripod, monopod, and a phone mount. Am I forgetting something? Do I need a different/better telemetry radio for longer range use. It would be nice to set up a base and be able to use the rover up to maybe 1/4-1/2 mile away. Will this setup allow me to set up one Facet as a base station and use the other as a rover when high accuracy is desired? My thought was to get 2 facets so we have the option to use them independently when only a lower accuracy is required. I currently use my iPhone and the QField app extensively for field data collection, but I’d love to get more accurate/useful data.
That’s pretty much what I do. I use a surveyor’s tripod and tribrach to accurately position the base Facet over a mark I set in the ground. I use a tape measure and record the height of the base over the mark. I gather static data at the base for a few hours and then post-process with OPUS to get accurate coordinates for the mark.
I go back a couple days later, set up the base over the same mark, measure it’s height today over the mark, configure the base to the coordinates from OPUS (taking into account the new height), and hook up one telemetry radio to the base. I put my rover Facet on a surveyor’s pole & bipod, hook up the other radio, and turn it on. I measure the height of the rover. Wait a minute or two for a fix, and off I go.
There are MANY details to getting this right. There is a lot of information in the guides and videos. Be patient, this isn’t a turnkey push-the-button exercise. It took me a while (weeks&months) to make mistakes, realize things weren’t working out, figure out why, and know not to make that mistake again. The learning curve is probably months. Just setting up the base accurately over mark is a skill to learn by itself. Post-processing is topic with lots of gotchas. Be careful with the coordinate reference frames! Test and verify before you trust it. There’s a fair bit to learn.
That said, once you figure it out, it works amazingly well. I don’t know what your accuracy requirements are; mine are pretty tight. I’ll take multiple observations separated in time by an hour or two or three of important points.
My limiting factor is the range of the telemetry radios. Check out the 1w telemetry radios SparkFun sells; the Holybros are 100mW.
bridger:
engineering firm and having a more accurate gps system would be very helpful especially for GIS tasks.
I was in the same boat. For my Civil Engineering Projects, we’ve always used expensive “Survey-Grade” equipment from the big 3 companies. Typically that’s NTRIP using CORS with a Network Rover. We use State Plane Coordinates for our Civil Projects, which the branded data collectors have no issues with.
I’ve been using/testing all of the SparkFun RTK products (except the Express Plus w/ IMU).
After testing, I can say I’m just as confident in the Opensource SparkFun RTK line as I am with my expensive equipment.
However, the Opensource world is lacking a good solution for the Data Collector Software for surveying and engineering work.
But for GIS (as you mentioned), we are extremely impressed with the Facet L-Band Units.
Since our GIS Deliverables always uses WGS, it’s a natural fit with Zero Fuss.
There’s no dealing with establishing Control, Radio Links, Reference Frame from each CORS, Cellular Service, etc.
We’ve even started using the Facet L-Band in some of our Civil Work too, such as Highway Crossing Profiles, etc.
We’ve had a couple clients purchase a Facet LB after seeing the simplicity.
The thing to remember is the Facet L-Band can operate just like a normal Facet, but it’s also adding another tool in your toolbox in the same formfactor.
I know that I sound like a salesman. Being 100% Honest - I wasn’t expecting much from the L-Band Corrections. I only added the Facet LB to our Testing just to cover all the bases with zero expectations that it would come out on top. We now have 12 or 13 and are about to place another order. 
I’m glad to answer any questions about our experiences with the RTK Product Line.
Ryan F.