Re: aerial IR of plants

["Lee Tarpley" <tarpley@xxxxxxxxxxxxxx>]

Ron Aavang wrote concerning "Sony Night Shot Digital VideoCams"
> >    
> 	The use of IR for vegetation is one of the scientific uses it is
> good for. It will show you healthy plants and plants that are not as
healthy
> because healthy plants reflect a lot of IR, if diseased or malnourished,
> plants reflect less IR and show up darker, or less red if you use EIR. I
> like using HIE and EIR from a small airplane to photograph my brothers
farm
> fields to look for unhealthy/underfertilized areas. If he knows where to
> look he might fine that the problem is a bug or a weed or something he
can
> spray for and he can then cure the right problem and get a larger yield
in
> the fall harvest. 

Just a clarification. The amount of reflectance of the very near infrared
radiation (VNIR) by an individual leaf does not change much for many
stresses. From high up, a decrease in VNIR reflectance is due to a change
in the amount of leaf material observed per ground area. This change in
foliage density can be due to loss of leaves or drooping of leaves, both of
which can occur in stress.

Lee Tarpley
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