PeteM, we have already discussed this earlier in this thread. It’s not just about accuracy and how much the equipment costs. Like I said before, repeatability and confidence play a big part too. And GCPs shouldn’t even be a factor because you have to have them no matter what you use.
You are obsessed with $3-4000 difference being a lot of money for survey equipment. To buy the survey equipment to do conventional or GPS surveying you would likely spend anywhere from $20-100k. And spend more time on the ground. There is already a huge savings using drones, so debating the last couple thousand is silly to me.
Bigriver, I don’t have any comparisons or hard numbers to answer your question but I have more confidence in the vertical accuracy and precision with the P4RTK. That’s what’s important to me.
And regarding the calibration of the camera, the cameras are the same and one is not “better calibrated.” The difference is with the P4RTK, you are able to use the original distorted pictures and DJI provides the calibration values to use in post processing. This is how photogrammetry has always been done. Photogrammetrists would regularly have to send out their camera to have it calibrated and they would get the calibration values specific to their camera to use on their pictures. On the P4P, the pictures are automatically undistorted with unknown values in the camera and the photogrammetry software will calculate a calibration based on those pictures.
You are obsessed with $3-4000 difference being a lot of money for survey equipment. To buy the survey equipment to do conventional or GPS surveying you would likely spend anywhere from $20-100k. And spend more time on the ground. There is already a huge savings using drones, so debating the last couple thousand is silly to me.
Bigriver, I don’t have any comparisons or hard numbers to answer your question but I have more confidence in the vertical accuracy and precision with the P4RTK. That’s what’s important to me.
And regarding the calibration of the camera, the cameras are the same and one is not “better calibrated.” The difference is with the P4RTK, you are able to use the original distorted pictures and DJI provides the calibration values to use in post processing. This is how photogrammetry has always been done. Photogrammetrists would regularly have to send out their camera to have it calibrated and they would get the calibration values specific to their camera to use on their pictures. On the P4P, the pictures are automatically undistorted with unknown values in the camera and the photogrammetry software will calculate a calibration based on those pictures.