I have a query regarding the PPK Workflow for Emlid Studio.
I will be collecting data using the PPK method for Base and Rover. The Base will not be over a known point. We will be logging Base data observations for 3 hours. I will then collect the coordinates of GCPs using the Rover unit.
After completing data collection I will be able to Post Process the data with Emlid Studio. However, I will be given the ‘official known coordinate’ of the location of the Base Station by a another topographer a week later. I will be able to compare my base coordinates with the Topographers, but I must correct the Rover coordinates (GCPs) using the coordinates of the Topographer.
How do I go about doing this in Emlid Studio?
As always, thanks in advance to anyone who is able to help out.
I would say the stop and go workflow will be the best option within emlid studio. Emlid support docs is very clear on the process, link below.
A few bits first on the data collection. Just to be sure, you will be running two gnss units for the task? The base unit on your soon to be final supplied position and a rover. Set these up and logging rinex data at the same time. All the constellations active within the logging. The guide says to log base at 1hz and rover at 5hz. I’ve not found any reason to deviate from that. You could up the rate if you want. Then use the survey app for flow to capture your GCPs. There is no hard and fast for durations there but a few minutes (2-5) on each position is a good rule of thumb. The collection tool in flow will allow you set the time etc. Good practice would say to:
Setup base and start logging
Setup rover and log GCPs
Fly missions
Second round of same GCPs as a check at the end to confirm positions.
Stop logs and download data, pack up. Export survey from flow (app or 360).
The data you have can then be imported into emlid studio. The layout is very clear. Take the rover file into the rover section. The pole height is taken from your flow CSV file (step 2). Drop the base rinex into base section. This is where you enter the provided position. There is a drop-down on the base location. Select manual, and then enter the position given to you. Make sure the antenna height has been applied for your file, relative to the point on the ground. The options for point entry are DMS, decimal degrees or Cartesian XYZ so as long as you have one of those from the client you are fine. If not the UTM or grid position can be converted using flow to get the geographical position. The navigation file can be either from the base or rover (p file). It doesn’t make any difference.
The default settings should be fine for a close base location. Run the first stage. This will give you a track for the rover, hopefully all lovely “fix” green. The stop and go file is now open. Drop the survey csv file there and hit go. This will then process that file back against the PPK rover track to give final positions. And that should be you all done.
Yes, you can later reprocess your raw data logs in Emlid Studio using the known coordinates of your base. By default, the software will use the RINEX Header Position when you upload the base log. But if you have the exact coordinates of your base, you can enter them manually, including the antenna height.
