Here is some resized and compressed imagery from part of a local vineyard (this area is about 200x300m). This was taken about 10 days ago, which is close to harvest time so the plants are very far from maximum vigour. Nevertheless, all three images show severe stress and actual plant loss on the East side of the vineyard (left side of the image since it has not been oriented to North. The angle of viewing is in fact from the North East and the path down the middle of the vineyard runs at about 170 deg North To South).
Some things to take note of:
– the sun was to the West and the imagery was taken at about 2pm, so the shadows run to the East of the vines. Shadows give false foliage data in the NDVI and the ‘true’ foliage is thus the line to the West (left in the image), when there are two lines.
– Being Autumn here, no foliage scores are particularly high, but the lawns in the houses on the surrounds are relatively healthy, and compare with the healthy parts of the vineyard in NDVI score.
This imagery was generated primarily using free and open source tools. Thanks to:
– Ned Horning for his Photomonitoring resources.
– Brenden Duffy for resources: video tutorials, links to software: VisualSFM, CMPVSM 6.
– Tools used: PaintShop Pro 8.0, Fiji and Photomonitoring plugin, VisualSFM, CMPVSM 6, Meshlab.