Altitude Above Ground Level

[dylanthecat]

My high powered laser rangefinder will simply burn through vegetation. I will use a curved trajectory laser to accommodate aircraft angle. It's all pretty simple.

 

[dylanthecat]

How are you going to 'merge' the ranger finders output (height/distance to GND) into GO4?

Mount the readout of the rangefinder to the area of full right rotation of the camera. When I want to know my altitude I just rotate the camera full right and I have my reading.

 

[Keule]

When I want to know my altitude I just rotate the camera full right and I have my reading.

That's a Redneck solution

 

[TXBidean]

DJI GAVE YOU GPS AND GLONASS, NOW NLD GIVES YOU EUS GALILEO TOO! NEW NLD GO 4.1.22 INSTRUCTIONS FOR GOOGLE MAPS:
New NLD GO 4.1.22 instructions for AGL height over changing terrain:
Tuesday, July 10, 2018

To enable displaying of AGL height over changing terrain, for this function to work correctly for NLD GO 4.1.22 - you will need to do a couple of things:

1. Go to Earthdata Login and sign up for an account
2. Go to 30-Meter SRTM Elevation Data Downloader and download up to 4 "tiles" for your flying area and save them to your device you use with GO
3. Install NLD GO 4.1.22. You will need to copy these "tiles" to a your device in the DJI\srtm_data folder. Leave them zipped, so they would look like N21W172.SRTMGL1.hgt.zip and so on.
4. Copy and paste the names of these files into a .json file installed on your device. (Due to the different data sets, we can't do this for your area) Go to DJI\og_settings and edit the dtm.settings.json file. This will be easier to do on your PC. Open this file with the editor of your choice, or you can use Notepad. It will look like this:

{"m_AlgoChoice":3,"m_AlgoParams":[30.0,5.0,15.0,3.0,50.0,20.0,3500.0],"m_AltitudeOffset":0.0,"m_DTM_tiles_paths":["/mnt/sdcard/DJI/srtm_data/N21W158.SRTMGL1.hgt.zip","/mnt/sdcard/DJI/srtm_data /N21W159.SRTMGL1.hgt.zip"],"m_DoLogging":false}

1. Replace the names of the files currently in RED with the names of your files (“tiles”). Only replace the names of the two that are there and leave the rest of the text alone. So for my example, I will only have one to replace, so the result after editing will be:

{"m_AlgoChoice":3,"m_AlgoParams":[30.0,5.0,15.0,3.0,50.0,20.0,3500.0],"m_AltitudeOffset":0.0,"m_DTM_tiles_paths":["/mnt/sdcard/DJI/srtm_data/N21W172.SRTMGL1.hgt.zip"],"m_DoLogging":false}

1. Save your changes and transfer back to your device, replacing the one that is currently there. (DJI\og_settings\dtm_settings.json) Keep a backup of the original. All you want to do is replace N21W158.SRTMGL1.hgt.zip and or N21W159.SRTMGL1.hgt.zip with the name of your tiles for your area. Make changes to this file as you fly in different areas that need different tiles. Check the map here: http://dwtkns.com/srtm30m/ You can have up to 4 tiles listed at a time in this file.

Galileo satellite support built into this version of GO will be implemented soon!! (in the mean time, this would be all you do to get it working, once we turn it on)
Install NLD GO 4.1.22. Allow NLD GO to have a data connection for a short while before or at the field with your bird connected. This allows the sat info to be downloaded quicker into GO and transferred to your bird. You only need to do this once for the initial download. Thats it! Enjoy!
`Quad808 and the rest of the NLD crew

Thanks much for all of the feedback. This appears to be a relatively complex to implement “approximate” solution. Might investigate it if someone has actually tried it successfully.

 

[rickw]

go to no limit dronzes and ask them

 

[Inspirephil]

No Limits Drones.com can do this for mavic pro,but not pro 2

Not yet anyway.

 

[Joe Boudreault]

It appears that the altitude reading in the Go4 app is the altitude above/below the launch point. If I am correct, is there a way to set it to above ground level (AGL) from the drone’s immediate location? I know that this is probably just wishful thinking as the Mavic 2 doesn’t have ground facing radar. Or radar of any type for that matter.

If your drone is in an auto mode, the bottom sensors will automatically detect how far off the ground you are; ie, how far above whatever is directly below the drone at any time during flight. I have launched my drone from a patio deck and then landed it on the driveway four feet lower... it sees the area directly below it. Also, you can always switch to manual landing if needed.

 

[sar104]

If your drone is in an auto mode, the bottom sensors will automatically detect how far off the ground you are; ie, how far above whatever is directly below the drone at any time during flight. I have launched my drone from a patio deck and then landed it on the driveway four feet lower... it sees the area directly below it. Also, you can always switch to manual landing if needed.

The sensors only work up to around 10 m - they will not give you altitude AGL above that.

 

[Mr. Salty]

If your drone is in an auto mode, the bottom sensors will automatically detect how far off the ground you are; ie, how far above whatever is directly below the drone at any time during flight.

The drone uses a barometric sensor for altitude data, not the bottom sensors, and it's in relation to the takeoff point, not the actual altitude above ground level where the drone is. If you're flying over uneven ground you have to mentally compensate for terrain changes.