There are some people doing something similar with drones. Just saw a presentation on this a few weeks back. https://support.dronedeploy.com/v1.0/docs/ndvi-algo

There are some people doing something similar with drones. Just saw a presentation on this a few weeks back. https://support.dronedeploy.com/v1.0/docs/ndvi-algorithms https://support.dronedeploy.com/v1.0/docs/ndvi-algorithms. Measures the difference between blue and near infrared to infer things about plant health, although I don't believe it indicates for specific diseases. Good luck with your work!