DJI Mavic 3 Enterprise RTK, PPK, VRS Accuracy Tests

We tested out the new Mavic 3E RTK for surveying accuracy using VRS (NTRIP) corrections, using the Emlid Reach RS2 as a base station and sending RTK corrections, and using the Emlid Reach RS2 to store data in order to process PPK in Emlid Studio.  Below are the results from those tests, beginning with the optimal solution.

M3E RTK with Emlid Reach as RTK Base Station, 8 MPH Flight Speed

The Mavic 3E received correction using an Emlid Reach RS2 as a base station.  In order to transmit corrections from the RS2 to the M3E, the M3E controller connects to the RS2's hotspot (no internet access needed).  Then, the local NTRIP credentials given by the RS2 are entered into the M3E Custom RTK setup.  

Sidelap was set to 70%, overlap was set to 80%.  Altitude was set to 174 feet, and flight speed was set to 8 mph.  Under these conditions the Mavic 3E can cover ~1 acre per minute of flight.  Assuming a return to the home point at 30% battery and good conditions, the Mavic 3E can cover ~30 acres in a flight at 0.56 inch Ground Sampling Distance.

The check points were collected with the Emlid Reach RS2 as a rover, and receiving corrections from the Emlid Reach RS2

No GCPs were used.  No vertical translation was needed.  Three check shots were used to check the accuracy of the result.

The RMSE of the Easting, Northing, and Elevation on the check shots was, 0.055', 0.097', and 0.033'. The accuracy of the check shots themselves is imperfect, given we shot them with RTK GNSS rather than a more accurate method such as a total station.  But, the same base station was used for the drone as was for the rover collecting GCPs, which should contribute to a good comparison.

Sample Mavic 3 Enterprise RTK Data Here

Pix4D Quality Report

M3E RTK with Emlid Reach as RTK Base Station, 33 MPH Flight Speed

The Mavic 3E received correction using an Emlid Reach RS2 as a base station.  In order to transmit corrections from the RS2 to the M3E, the M3E controller connects to the RS2's hotspot (no internet access needed).  Then, the local NTRIP credentials given by the RS2 are entered into the M3E Custom RTK setup.  

Sidelap was set to 70%, overlap was set to 80%.  Altitude was set to 174 feet, and flight speed was set to 33 mph.  Under these conditions the Mavic 3E can cover 3.25 acre per minute of flight.  Assuming a return to the home point at 30% battery and good conditions, the Mavic 3E can cover 102 acres in a flight at 0.56 inch Ground Sampling Distance.

The check points were collected with the Emlid Reach RS2 as a rover, and receiving corrections from the Emlid Reach RS2

Like the Phantom 4 RTK, the M3E RTK is very accurately horizontally out of the box, but needs a translation in the Z axis.  One point on the project was used for a constant vertical translation.  No GCPs were used.  Three check shots were used to check the accuracy of the result.

The RMSE of the Easting, Northing, and Elevation on the check shots was, 0.055', 0.158', and 0.043'. The accuracy of the check shots themselves is imperfect, given we shot them with RTK GNSS rather than a more accurate method such as a total station.  But, the same base station was used for the drone as was for the rover collecting GCPs, which should contribute to a good comparison.

The Mavic 3E camera includes a mechanical shutter.  The camera does not store each pixel at the same time, as a true global shutter.  It still operates a rolling shutter behind that mechanical shutter.  At slower flight speeds, the mechanical shutter closes off the light fast enough that it acts as a global shutter.  At faster flight speeds, the mechanical shutter may not be fast enough to eliminate the rolling shutter effect.  In this case, the data set was run a second time with the rolling shutter correction and the RSME improved to: 0.065', 0.074', 0.046'. 

Sample Mavic 3 Enterprise RTK Data Here

Pix4D Quality Report

M3E RTK with Emlid Reach as PPK Base Station, 33 MPH Flight Speed

The Mavic 3E received correction using an Emlid Reach RS2 storing data for PPK.  The Emlid Reach RS2 can also be configured to send correction in real time to the Mavic 3E.  In this case the data from the Mavic 3E and the Reach RS2 was post-processed with Emlid Studio in order to process the accurate image locations.

Sidelap was set to 70%, overlap was set to 80%.  Altitude was set to 174 feet, and flight speed was set to the fastest at 33.5 mph.  Under these conditions the Mavic 3E can cover 3.25 acres per minute of flight.  Assuming a return to the home point at 30% battery and good conditions, the Mavic 3E can cover 102 acres in a flight at 0.56 inch Ground Sampling Distance.

The check points were collected with the Emlid Reach RS2 using ODOT VRS for corrections.  

Like the Phantom 4 RTK, the M3E RTK is very accurately horizontally out of the box, but needs a translation in the Z axis.  One point on the project was used for a constant vertical translation.  No GCPs were used.  Three check shots were used to check the accuracy of the result.

The RMSE of the Easting, Northing, and Elevation on the check shots was, 0.128', 0.094', and 0.028'.  The accuracy of the check shots themselves is imperfect, given we shot them with VRS rather than a more accurate method such as a total station.  Because of that and the fact that we also used VRS on the drone, we expect the accuracy to be even better when using the same base station.  

The Mavic 3E camera includes a mechanical shutter.  The camera does not store each pixel at the same time, as a true global shutter.  It still operates a rolling shutter behind that mechanical shutter.  At slower flight speeds, the mechanical shutter closes off the light fast enough that it acts as a global shutter.  At faster flight speeds, the mechanical shutter may not be fast enough to eliminate the rolling shutter effect.  In this case, the data set was run a second time with the rolling shutter correction and the RSME changed to: 0.253', 0.060', 0.055'. 

Sample Mavic 3 Enterprise RTK Data Here

Pix4D Quality Report

M3E RTK with VRS (NTRIP) Base Station, 33 MPH Flight Speed

The Mavic 3E received correction using the ODOT VRS NTRIP service.  Sidelap was set to 70%, overlap was set to 80%.  Altitude was set to 174 feet, and flight speed was set to the fastest at 33.5 mph.  Under these conditions the Mavic 3E can cover 3.25 acres per minute of flight.  Assuming a return to the home point at 30% battery and good conditions, the Mavic 3E can cover 102 acres in a flight at 0.56 inch Ground Sampling Distance.

The check points were collected with the Emlid Reach RS2 using ODOT VRS for corrections.  No GCPs were used.

Like the Phantom 4 RTK, the M3E RTK is very accurately horizontally out of the box, but needs a translation in the Z axis.  One point on the project was used for a constant vertical translation. No GCPs were used.  Three check shots were used to check the accuracy of the result.

The RMSE of the Easting, Northing, and Elevation on the check shots was, 0.101', 0.148', and 0.097'.  The accuracy of the check shots themselves is imperfect, given we shot them with VRS rather than a more accurate method such as a total station.  Because of that and the fact that we also used VRS on the drone, we expect the accuracy to be even better.  In the next accuracy test we will use the Emlid Reach RS2 as a base station for both the rover check shots and the Mavic 3E RTK.  We expect that to show even better results. 

The Mavic 3E camera includes a mechanical shutter.  The camera does not store each pixel at the same time, as a true global shutter.  It still operates a rolling shutter behind that mechanical shutter.  At slower flight speeds, the mechanical shutter closes off the light fast enough that it acts as a global shutter.  At faster flight speeds, the mechanical shutter may not be fast enough to eliminate the rolling shutter effect.   In this case, the data set was run a second time with the rolling shutter correction and the RSME changed to: 0.158', 0.111', 0.040' . 

Sample Mavic 3 Enterprise RTK Data Here

Pix4D Quality Report