From what I understand, yes that is the case. Even with major brand GPS systems PPK and RTK logs are different.
RTK and PPK are two different kinematics technologies that reference data in different ways. Although PPK generally has slightly higher positioning accuracy than RTK, both achieve centimeter-level precision. RTK is recommended for flying in environments that allow for real-time connection via OcuSync or 4G and prefer convenience and efficiency. For users who have no demand on timeliness and/or need to operate in conditions without connectivity, PPK is a better option.
The PPK files are as follows.
EVENTLOG.bin is a binary format that stores exposure, time stamp and log file.
PPKRAW.bin is an RTCM3.2 MSM5 format that stores satellite observation data and ephemeris data.
Rinex.obs is a Rinex file format that is created after transcoding.
Timestamps.MRK is a ASCII format that stores exposure and time stamp.
So here again, from what I understand the Rinex OBS is the base station and the rover (drone) is inside of the Event BIN file so it needs to be extracted. PPK BIN should contain the NAV information, but I do not know if it is from the base or the drone. Typically when I do PPK with a drone I use the NAV data from the drone.
Buy the Base Station for 2000 Euro and thanā¦ I dont know, I have not purchased because it is useless for surveys in areas without phone signal.
Purchase a EZSurv license. That is 3000 Dollar once and 300 Dollar annually. RTK needs to be off during the flight and the Data are reliable. The customer service (Stephanie) is amazing helpful (relay she is!).
After 3 month of time wasting with RTK LIB I surrendered. The P4 RTK is not delivering the necessary data for it.
An other commend here is suggesting Klau, maybe they are providing a trial. You can use a EZSurv trial to check if it is working for you.
The whole point of the base is so that you can use a CORS/VRS to correct the base as it provides corrections to the drone, you donāt need a service with PPK which is why I would highly recommend a base station. Also, by doing PPK it does not have to be DJIās base as long as it records RTCM3 or at least a format that can be converted.
Straight from the horseās mouthā¦ I am starting to think they made the PPK process proprietary inhouse. The roadblock I have hit is the inability to extract the BIN files.
I was going to continue pasting screenshots, but that is the meat of it. There is more Here.
Hey Mike, take a look at this site and see if this helps you with the processing of P4RTK data using rtklib. This site gives you a step by step process of how to get all th data you need to use the rtklib (if you didnāt already know)
This is a result of a flight I just processed so far. Looking at the plot the flight had a gps fix most of the flight. The controller showed I had 30 FIX sats.
In order to perform PPK corrections, we will need 3 files.
A āroverā file, which is the RINEX data that comes directly from the Phantom 4 RTK
A ābase stationā file, which is the RINEX observation data for a fixed base station. For this workflow, we will use publicly available CORS base station data.
Broadcast ephemeris data, which is the precise satellite navigation data. For this workflow, we will use data provided by NASA CDDIS.
So far Iāve made it all the way down to processing the files and using the Excel spreadsheet. The output isnāt working properly, but it could be a copy/paste error on my side. Iām doing some excel code reading to figure out what the output process is doing.
We just need to keep hammering on this. Feels like we are getting pretty close. If you donāt realize we could be on the brink of something that a processing company could do on the backend automaticallyā¦
As for looking at an add-on, I would highly recommend it. I am getting 2-3cm absolute with my Emlid, but I still use 4-5 GCPās. My setup was a $400 add-on to a stock P4P.
Donāt worry about what you are doing wrong just yet.
Having the settings selected correctly for this workflow is critical to obtaining good results. Below are the settings that Aerotas has found leads to the most accurate results. Only the settings that have been changed from their default are noted.