I need some help trying to enter custom GNSS coordinates in the advanced section of the M300 controller. I have used NTRIP as a custom network and it works fine but I would like to use the RTK2 and apply known coordinates in the advanced section. At this time I'm using an Emlid RS+ with NTRIP corrections achieving cm and sub-cm accuracy to get my known point for the base or GCPs. I can apply the updated lat & long in the advanced settings taken from the Emlid with no problem but have been unable to apply the elevation. I have tried feet, meters, and ellipsoid heights using different local coordinates but nothing works. When entering the elevation numbers it shows an error message. I saw someone else do this with the M210. I know it's a different UAV and Pilot app but it should still work. The only difference is the old Pilot app used with the M210 referred to elevation and the new M300 Pilot app says Elipsoide. After talking to REDcatch support they advised that setting up the RTK2 over a known point and manually correcting the lat, long, and elevation on the radio RTK settings is the most accurate way to use the RTK2. Does anyone have any ideas?

what does the error message say, Mike?

Euis Posted at 1-17 02:27
what does the error message say, Mike?

I need to set everything up and use the Emlid as I did before so I can make sure I can capture the exact
message. I have this same question posted on the Emlid forums. The only response I have received was there was a belief that the Emlid was receiving local corrections thru NTRIP and those coordinates did not play well with the WGS84 that the RTK2 is using. I was also wondering how accurate can the RTK2 be if I'm using the custom network and my NTRIP provider is using NAD83 coordinates? I tested this several weeks ago and got some strange positions of my GCPs. I stored each GCP coordinate as NAD83 using the same coordinates that Emlid suggest and all of them were about +25 above ground. Funny that when I adjusted their elevation they set perfectly on the GCP points. Obviously, there seems to be some kind of coordinate incompatibility issue. I'll try to get some information later today. Thanks for the interest.

Euis Posted at 1-17 02:27
what does the error message say, Mike?

Ran some tests today and the error message says that I'm out of range. The elevation "ellipsoid" using the RTK is in meters not feet. I ran 6 different tests using feet, meters, and ellipsoid. I converted feet to meters and it showed about 56.8 meters at my location. Most of the coordinates were recorded in meters including the ellipsoid and basically recorded the same elevation. All the lat and long were almost identical. The numbers recorded in meters with the Emlid were about 5 meters off from what the RTK2 recorded. Once I changed the RTK elevation to what the Emlid recorded it did take those numbers with no errors BUT I never could get the RTK out of the converging mode. AT this point I really don't know what numbers to believe. If the numbers recorded by the Emlid are correct then the RTK elevation is off by 5 to 6 meters. If that is correct then I can see why all my GCPs are +25 feet higher than the maps I'm processing. Mixing RTK recorded with WSG84 and Emlid using NAD83 makes me wonder how any of this can be trusted. Also, I did do a test last month by using a custom network and my NTRIP service provider. All my GCPs were +25 above the map. I'll have to keep digging until I feel comfortable.

mikes1 Posted at 1-17 15:42
Ran some tests today and the error message says that I'm out of range. The elevation "ellipsoid" using the RTK is in meters not feet. I ran 6 different tests using feet, meters, and ellipsoid. I converted feet to meters and it showed about 56.8 meters at my location. Most of the coordinates were recorded in meters including the ellipsoid and basically recorded the same elevation. All the lat and long were almost identical. The numbers recorded in meters with the Emlid were about 5 meters off from what the RTK2 recorded. Once I changed the RTK elevation to what the Emlid recorded it did take those numbers with no errors BUT I never could get the RTK out of the converging mode. AT this point I really don't know what numbers to believe. If the numbers recorded by the Emlid are correct then the RTK elevation is off by 5 to 6 meters. If that is correct then I can see why all my GCPs are +25 feet higher than the maps I'm processing. Mixing RTK recorded with WSG84 and Emlid using NAD83 makes me wonder how any of this can be trusted. Also, I did do a test last month by using a custom network and my NTRIP service provider. All my GCPs were +25 above the map. I'll have to keep digging until I feel comfortable.

I ran more tests over the last few days and I did get the elevation "ellipsoid" from the Emlid to inter in the advanced settings. As I said before, the lat and long was no problem. The elevation has to be in meters. I took readings with the Emlid RS+ and there was about a 4 to 6-meter difference between the RTK2 and Emlid. I feel pretty confident that the Emlid is correct which is a surprise, if not a disappointment, that the RTK2 was so off. The lat and long were real close and I could change them to match the Emlid with no problem. At the present time I'm working with REDcatch to develop a workflow I can count on but it has been difficult to achieve results that I believe are correct.

mikes1 Posted at 1-22 09:16
I ran more tests over the last few days and I did get the elevation "ellipsoid" from the Emlid to inter in the advanced settings. As I said before, the lat and long was no problem. The elevation has to be in meters. I took readings with the Emlid RS+ and there was about a 4 to 6-meter difference between the RTK2 and Emlid. I feel pretty confident that the Emlid is correct which is a surprise, if not a disappointment, that the RTK2 was so off. The lat and long were real close and I could change them to match the Emlid with no problem. At the present time I'm working with REDcatch to develop a workflow I can count on but it has been difficult to achieve results that I believe are correct.

Why are you trying to use the RTK2 if NTRIP is working for you? I have a RS2 as the base for the 300 instead of the RTK2 via Emlid Caster service until I sorted out my NTRIP connectivity. Now I just use the correction network with GCP's. Just curious is all.

I have no comfort level with DRTK base station for elevation data..been using NTRIP connection to CORS network. DjI Base station collects  dust in garage. Only will use if no cell coverage.

I did a bunch of experiments with it last summer and compared to known elevation points. Always off by way more than I could tolerate for what I am doing.

robertnd2 Posted at 4-7 19:22
I have no comfort level with DRTK base station for elevation data..been using NTRIP connection to CORS network. DjI Base station collects  dust in garage. Only will use if no cell coverage.

I did a bunch of experiments with it last summer and compared to known elevation points. Always off by way more than I could tolerate for what I am doing.

Yes, I have found the RTK2 elevation can be off several feet at times. I do use the RTK2 in areas that have no cell service or when I need precision flight in areas that degrade the onboard GPS. I have also done more testing and I can get very accurate elevations with the RTK2 using the Emlid corrections. You can input the coordinates you measure with the Emlid into the custom settings OR use your NTRIP login using the custom network. I like to use the Emlid to collect my GCPs and connect the M300 to the RTK2, using corrections measured with the Emlid or via NTRIP. You could skip the RTK2 and just use the Emlid for mapping but a lot of times I'm flying very close to cell towers and don't want to take a chance on having my RTK connection drop out because of a bad cell connection. That doesn't happen with the RTK2. Lot's of ways you can approach this and different reasons why you would want to use one method over another. Find a method that works and one you are comfortable with. Thanks for your input.