Accuracy Question - Parrot Sequoia

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

Hello, 

I have a question regarding the map accuracy resulted after processing, with Pix4Dmapper, multispectral images obtained with Parrot Sequoia. We need an accuracy of under 1 meter for a project where we’ll do analyses on very small plots over a period of time.

We’ve used GCPs and a RTK station to get the accurate middle of the GCPs, after this we’ve added the images obtained with Parrot Sequoia and the GCPs and processed everything in Pix4Dmapper.

Just to be sure, can anyone confirm that in order to read the resulting accuracy I have to look at the first page of the Quality Report under Quality Check > Georeferencing > yes, 5 GCPs (5 3D), mean RMS error = 0.145 m? If it’s not that, then where should I look to find out if I obtained an accuracy of under 1 meter?

Also can anyone tell me why on the first page of the Quality Report the georeferencing line has an yellow triangle? I ask this because the GCPs we’re marked as good as I could.

And can anyone tell me why on the last page of the Quality Report under “DSM, Orthomosaic and Index Details the Radiometric calibration with reflectance target” and all the “Camera Radiometric Correction” are with a red triangle?

I’ve attached the 4 quality reports that I generated from the start trying to improve the accuracy of the map: https://drive.google.com/open?id=1DKmz4QNsUuG8a7MOmFNC_nW_L_oBsKgM 

Can anyone check them out and give me feedback?

Thank you.

2

Hi Alex,

You can check out this community link: https://community.pix4d.com/t/7711-DJI-Phantom-4-PRO-and-GCPs

And can anyone tell me why on the last page of the Quality Report under “DSM, Orthomosaic and Index Details the Radiometric calibration with reflectance target” and all the “Camera Radiometric Correction” are with a red triangle?

I looked at your quality reports. The red triangle in reflectance targets mean the panels were either overexposed or not correctly detected and the data was not used for calibration. Only the data from the Downwelling light sensor was used.