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Colby, Kansas | Marvin,
I would agree that the YM data is hard to get in some cases, and worse yet the question of "Did they even bother to calibrate it??", I think the precision ag industry/research/retailers are somewhat to blame for this as its taken a long time to get where we can make some sense of YM data. The example you have of the corn borer infestation was excellent and made a clear example of a role for imagery. I like the idea of having both and investigating the divergences between them.
You make the argument that yield data hasn't been dependable, but the key part of that is dependable for what? Because the yield data you get is certainly an accurate quantification of what happened (making the assumption of a calibrated YM). In the case of the corn borer example the YM data may not be dependable if I'm trying to do a multi-year analysis to determine yield stability. But if I'm using my yield data to calculate Phos and Nitrogen removal it certainly is dependable. And as the YM data may not accurately represent the yield potential of that area, the inverse is true as well in that the imagery may not accurately represent the nutrient status of that area either. I'm curious what other events you have in your environment that would impact your yield data, I know for us having a late freeze or hail on a wheat crop is an issue.
I was fortunate enough to spend a couple of days (early Summer 2006) with the Veris NIR rig, the one they brought out had the full spectrometer on it, they were still looking at which bands they wanted to focus on. We ran a bunch of transects on something like 60' spacing that we had also soil sampled every 30' down the line of the transect. We were trying to get a feeling of how well we could do spatial O.M. maps with it, the data are still under review, actually I think the Veris guys are waiting on me again for some more of the data, other projects have came up and this one was just a sideline for fun so it got shelved for now. If I have some time the next several days I'll try and dig back up the summary we had from it.
Regards,
Lucas
Edited by LHaag 1/13/2008 17:42
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FSA Image file question
