Hi All,
I recently started using Fields for creating prescription spot spray maps,
I’m having trust issues with the magic tool, I just can’t get to a point where I’m happy with its selections, even after identifying hundreds of wanted/not wanted cells. I’m already mapping 100ha+ fields at 1cm GSD and pushing processing times to the limit of being economically viable. Is there something I’m missing? or is the software just not as capable as I assumed it was?
M400+P1 camera. on RTK
100HA field green weeds on Barley fallow
1cm GSD
60/70 overlap
1.5m cell size
I’m finding the Prescription maps I’m delivering are geographically accurate but just missing too many weeds.
Appreciate any thoughts or Insites
Thanks Robbie
Hi Robbie, thanks for sharing your feedback with us. The issue I see here is that the contrast between the weeds and the background is really low, and that makes it hard for the Magic Tool to pick up those weeds.
For this Green-on-Brown scenario, a much better approach would be to use an index-based thresholding method: Weeds on fallow detection (Green on Brown) - PIX4Dfields . This works best with multispectral data, but you could try to use an VARI or TGI index for it if you only have the RGB sensor.
On the other hand, I saw that you submitted your labels for model training, so it could be that the next version of the MagicTool already knows much better how to do it in your specific case. So having this “Learn based on my data” option enabled helps us a lot.
Hi Again Julius,
I am currently on a 30 day trial, I have mapped a few fields and I definitely see huge potential with the program. However the current dry conditions here in Australia do leave little contrast between weeds and their background. I did try with a TGI index and it was certainly an improvement. I would like to try with the multispectral and have organised to borrow a drone and hoping to see the results before my trial period expires. Is there any chance of a small extension? i’m honestly not far off the quality of maps I need to provide a service, if this multispec imagery gets me over the line I will certainly take a 12 month subscription. i just don’t want to risk it yet
Thanks Robbie
Hi Robbie, I sent you a private message about that. The multi-spectral data with an NDVI layer that you threshold in soil and vegetation will be a great tool to solve exactly this.
