Making sense of methane fluxes with MATLAB Gavin McNicol EPS 209 Data source – Jaclyn Hatala & Dennis Baldocchi
Field Site & Method Sherman Island, Sacramento- SJ Bay Delta Collaboration with Baldocchi lab Eddy covariance flux measurements CH 4 CO 2 H 2 O
Diurnal methane fluxes Source: Jaclyn Hatala & Dennis Baldocchi
Cow Cam! Source: Detto et al. (2010)
MATLAB Image Processing Basic Goals: Find cows in image (color, texture, intensity) Produce vector of ‘cow’ and ‘no cow’ time points Can we do more than just presence/absence?
Results so far Individual images: can we see the cows? Range Filter
Results Individual images: can we see the cows? Mahalanobis distance
Results Range filter method on test images: 59% accuracy (type I error) Threshold
Results Unexpected result 18 th – 25 th January 2010
Next steps 1 – Combine mahalanobis distance information with edge detector 2 – Better to over-predict. 3 – Group photos by day as cows are never there all day and look at deviation from mean intensity. Questions?