Here + RTK Data logging

Hi guys and gals.

We have recently upgraded to a here + system.

I would like to find out if there is any way of typing in the co-ordinates (Instead of waiting for a certain amount of time to get a certain accuracy) forcing it to a co-ordinate measured using a survey grade GPS?

The reason being that we cannot always wait to fly as we do multiple flights per day at multiple sites.

Secondly does anyone have any suggestions with regards to a PPK system?

Thanks in advance for the assistance!

I have no experience with it but what I think you need to do is set up a reference station with the here+ base.

Ublox U-Center User Guide

In the user guide you have a section for NTRIP Server Setup, after you set it up you will get the corrections from a ntrip mount point instead of a com port. You might still be able to connect via com port, only way to know is to try.

There might be some other way to set the gnss location manually but I believe this is the correct way.

Another thing you can do is send your correction data to a service like so other people might benefit from the data and you can connect to the base via internet from anywhere.

Still, do keep in mind that L1 gps/glonnas is single frequency so range can be an issue in getting a rtk fix.

Regarding ppk, do you know which format is saved when you set raw gnss data logging in ardupilot. I believe it might be some ublox format as opposed to rinex, but it is possible to convert it to rinex. You will need raw data from a base station and raw data from a rover. Then you can use rtklib to post process. I belive you will get better data with straight up rtk. Even though ppk is more precise in position estimate rtk can do it on the fly, coupled with imu data you can get much higher resolution data, instead of 1-10Hz depending on the raw data frequency.

Imagine you are moving 5m/s(18km/h), if you gather 10Hz of data you can get a resolution of 0.5m. This is often combated with just iterating? (sorry, English isn’t my native language and I forgot the word, dividing into more steps in between actual points). But what ardupilot does is it knows when there is a shift in speed and with that data they can more accurately calculate the position when a eg. photo has been taken.

Best of luck and please respond with some results if you made ti work successfully

Thanks alot.

We have been working on it progress is just a bit slow so thaught there might be some people out there that have had the same issues.

We are able to change the lat and longs but unable to edit the elevations.

Will update once we have won the battle!

What GCS-software are you using?
We use MP and I’ve put in the reference coordinates manually multiple times (from a survey GPS). I just enter the lat/long/elevation and click “use”.

we are also using mp. Will have to check all my firmware versions then.

Do you just download the flight log when complete? Does it automatically tag the images in mp?

@triise we keep getting an rtk float if we type in coordinates. Is it possible that it is a firmware issue. Do you perhaps know what versions yo are running on?

We are using 1.30 (uBlox firmware that is).
We are using our custom software to tag our images with the dataflash log.

Great thanks. Will update on whether i get something right or not