ok so this has been bugging me for a while and i finally have to ask because im going in circles. flying a phantom 4 multispectral over a corn field, maybe 200 acres, and the maps i'm getting out of pix4dfields look kind of banded ? like there are these parallel stripes that roughly line up with my flight lines and they're messing up the vegetation indices something awful

calibration panel gets done every flight, sun conditions have been pretty consistent, im flying at like 100m agl with 75/75 overlap which should be more than enough. the individual band images actually look fine to me but by the time it processes into ndvi the banding is really obvious especially in the red edge channel

anyone seen this before or know what im probably doing wrong ? genuinely stumped here

this is almost definitely a bidirectional reflectance issue, banding that follows flight lines is basically the classic symptom. the multispectral sensor on the p4m is pretty sensitive to sun angle relative to your flight direction. try flying your next mission with the sun behind you or at least not directly to the side, and also check if youre flying at the same time of day because even an hour difference can change things. some people rotate their grid 90 degrees and do a second pass and that can help with pix4d's ability to normalize it out

also worth checking if your calibration panel shots are being taken in shade vs full sun because thats caught me before ? the reflectance values just go sideways if theres any shadow on the panel even partial

had the exact same thing happen last summer, drove me insane for like three weeks. turned out for me it was actually the lens vignetting correction settings in pix4d that werent applying right ? there was some update that changed where that setting lived and i had missed it. probably not your issue but worth checking the processing report and seeing what corrections are actually being applied