RS+ vs RS2 With M300 RTK 2

At the present time, I’m flying the M300 with the P1 camera connected to the RTK 2 base. It’s my understanding that the RS+ will not work with the DJI drones. As I am already connected to the RTK 2 base I only need to get GCP locations. Do I need to connect the Emlid devices to the drone? If not, then isn’t the RS+ capable of giving me accurate GCP locations. Can someone please clear this up for me. Thank you.

I would run everything off the same platform. When you start crossing brands of equipment which carry slightly different algorithms you are going to see weird little errors pop up that can’t be explained. The RS2 is 10x better hardware than the D-RTK 2 but does that mean that it is a better base? Probably not. We use Topcon in construction and I can tell you that a Hiper+ from 2005 works every bit as good as a base station as a 2020 Hiper VR. Where you really see the difference is in roving and possibly on days with really adverse conditions.

The RS+ can definitely give you cm-level accurate points but it is not going to be as easy as an RS2 and even though the D-RTK 2 is L1/L2 the field experience is going to be about the same when collecting. If you are a patient person that accepts the downfalls of L1-only then it will work just fine. I used them for a couple of years and the overall experience was good but there were a few days in the when they almost became anchors.

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I really do appreciate the information. I do understand the RTK2 is not in the same class as the RS2. Wish DJI had put a little more effort into the design and construction but it is what it is. The RTK2 is also used when flying in areas where the GPS is not good or when flying around a lot of areas that would interfere with the drone’s GPS. If using the RS2 instead of the RTK2 would I get the same solid connection in those areas? At this point, I’m wondering if I should sell the RTK2 and just buy the set of RS2’s. What do you think?

If you are really wanting to rely on RTK geotagging then NTRIP straight to the P4RTK or the D-RTK 2 over radio are your cleanest solutions. I would run PPK before I ever ran corrections over radio to a drone. RTK via NTRIP on ours has been pretty good but there is still about a 3% float rate on average. When we tested the P4RTK over radio it was horrible simply for the fact that our projects were too big and anytime the environment wasn’t perfect we were dropping fix as much as 10% of the flight. NTRIP was much better but it became clear that for our grade-sensitive work that we could not blindly trust RTK so we always run the PPK to get the track for comparison. If we get more than a 5% float with the PPK then we automatically make the necessary adjustments and re-geotag using the PPK values. Most people that I have worked with are not even needing to go to this level and RTK-only providing a consistent +/- 5cm stakeout was just fine.

Thanks, that all makes sense.

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Hi @contact,

If you already have a base for your M300 drone, you don’t need to connect Reach to the drone additionally. You can actually use our device to collect GCPs. If your RTK 2 allows transmitting corrections in RTCM3 format, you can use it as a base for the Reach receiver. In this case, both Reach RS+ and Reach RS2 will be able to receive corrections and provide you with centimeter-level accuracy. As an alternative, the rover can get corrections from a remote NTRIP station to work in RTK.

The choice of the receiver depends on the conditions in which you are going to work. If your environment is an open field without any obstacles and the baseline doesn’t exceed 10 km in RTK, Reach RS+ should suit you. But if you do PPK mapping in more complex conditions like areas with rare vegetation, buildings, or cars nearby, I’d advise you work with Reach RS2. This multi-band receiver can obtain more satellite signals to calculate Fix faster and provide centimeter-level accuracy in the 60 km range in RTK. You can check this guide in our docs or this video guide to learn more about their difference.