RS3 connection as base

Reach RS3 RTK / PPK configuration
1

Hi all, I’m having a bit of a conundrum and would love to hear how others may have solved this!

Use-case: Lidar survey of 90 acre site, on a hill, with woodland at top of hill and bisecting the site.
Flying M350RTK.

Existing workflow:

  1. Use RS3 to set out and collect GCPs.
  2. Use my android phone to stream Ntrip corrections from RTK2go, hotspot to drone controller.
  3. D-RTK2 base station as back up.
    Problem: Stream is 20km+ away from location, phone signal can be patchy. D-RTK2 isn’t great.

Attempted workflow:

  1. Use RS3 to collect GCP’s
  2. Use RS3 as base station to collect and send corrections, via Emlid Caster
  3. RS3 has to connect to my phone hotspot to access internet
  4. Drone acts as rover, the RC uses phone hotspot to receive corrections from Emlid Caster.
  5. Moved base station for 2nd part of survey to remain in signal. This has proved to be an error!
    Problem: I have to split the survey area into sections (due to 500m VLOS rules). The central woodland and distance to take off point blocks signal between phone hotspot and RS3.

My questions then!

  1. I think that if I use a data SIM card in the RS3 (using as a base station), it will use that to connect to the internet (and so Emlid Caster), and not rely on my phone hotspot? Therefore, I don’t need to move the base station at all.
  2. I still need to connect the RC to Emid Caster, so only the RC will use my phone hotspot?
  3. I think I need to deactivate tilt compensation when used as base station?

In summary, the android phone hotspot is the biggest issue as the site is large and I can’t stay close enough to the RS3 (base) to keep connected!

I can’t be the only person seeing this problem, so how have you resolved this please?

2

My workflow is similar.

  1. Shoot in a GCP and the checkpoints with the RS3.
  2. Shoot in a base point and then occupy that point with the RS3.
  3. Then setup local NTRIP on the RS3.
  4. Connect your RC to your hotspot to network with the RS3 and then enter the local NTRIP credentials into the RC.

The only way you will lose fix is if your RC loses connection to the drone or if one of the devices dies. The downside is your RC and base need to be within range of the hotspot. In the past I have used a Verizon 4G modem which would allow you to add an amplifier if having the base near you isn’t an option.

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3

Thanks, the problem I seem to be having is the distance between the phone hotspot and the RS3 base. Could be 500m away, with woods in between and at a lower elevation. So I need to get rid of the hotspot OR get a booster as you suggest. Did you use a portable battery station to power the modem / booster? And how did you connect the modem to the internet in the field?

5

It’s truly a modem with a battery internally. My phone will propagate about 30ft so if I put it in the middle I can get 50-60ft from the base. This one works at about 60ft so 100-120ft total. The majority of the time it’s easy for me to setup the base where I am flying so I don’t worry about it too much but if I hit a site with no access then it can get tricky staying connected and maintain VLOS.

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6

Hi @Jubba,

If you’re using Emlid Caster with this setup, the base and the rover can be connected to different sources of the Internet. So you’re right. You can use a SIM card in the base and your mobile hotspot with the drone.

Yes, as Reach stands still, let’s turn off the IMU under Settings → IMU.

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