Jeff W/Chris F working on this feature for the upcoming Grassroots Mapping Forum:

###1. Science background###

* Is this your illustration: https://www.flickr.com/photos/jeffreywarren/5416397210/? We could modify that for B&W
* NIR by itself looks cool but does not highlight meaningful patterns well.
* NRG is false color IR with vegetation in shades of red and pink
* NDVI highlights areas of high or low photosynthetic activity

###2. A second camera to capture NIR###

* How to modify a camera
* How to mount two cameras

###3. Triggering the cameras in flight###

* Stay simple with rubber bands or independent intervalometers, but you might be sorry later
* Simultaneous triggering is pretty much the way to go
  * CHDK to enable synchronous remote via USB on Powershots
  * USB Y cable
  * MK111 timer
  * Radio control

###4. To capture general patterns###

* Synchronize the cameras’ clocks
* Capture jpgs
* Identify NIR/VIS photo pairs via timestamps
* Use Ned’s Fiji macro (requires well-overlapped, sharp photos, and good organizational skills)
* Make structure from motion models in Hypr3D
* Stitch images in MS ICE or GIMP
* Align images over a georeferenced map with MapKnitter

**Advanced:** To produce more precise results (link to web page):

* Synchronize the cameras’ clocks
* Capture RAW, convert to Tiff (need CHDK, big partitioned cards, RAWTherapee (e.g.), big hard drive)
* Identify NIR/VIS photo pairs via timestamps
* Use Ned’s Fiji macro
* Interpret pixel-level results (or almost)
* Make structure from motion models in Hypr3D or 123D Catch
* Stitch images in MS ICE,  GIMP, or Agisoft PhotoScan (allows GPS control)
* Align images over a georeferenced map with Mapknitter

###5. Interpretation###

* One-time maps can reveal side by side differences in plant growth or health (Lee, NH)
* Time series of NDVI can reveal seasonal or year to year trends in plant growth and health (TBD)

###6. Conclusion###

* online resources
* how to get involved