# Changes between Version 8 and Version 9 of DevWikiRealParameters

Ignore:
Timestamp:
Nov 29, 2011 11:17:22 AM (8 years ago)
Comment:

--

Unmodified
Added
Removed
Modified
• ## DevWikiRealParameters

 v8 [[Image(thetatest_ij.png)]] So, if θ,,test,, is more than 90 degrees, θ,,ij,, = - abs(θ,,ij,,). Otherwise, θ,,ij,, = abs(θ,,ij,,). So, if θ,,test,, is more than 90 degrees, θ,,ij,, = - abs(θ,,ij,,). Otherwise, θ,,ij,, = abs(θ,,ij,,). If θ,,ij,, has any value other than +-90 degrees, the basis vectors are not orthogonal and the transformed pixels are diamond shaped. Probably the most common value for θ,,ij,, is -90 degrees, which indicates that the transform "flips" the '''j''' axis. == Summary == The method presented here performs calculations in the coordinate system used by the geocoordinates. All of the parameters calculated by this method are tied to the same SRID referenced by the transform '''O'''. It is assumed that the x and y axes of the geospatial coordinate system are orthogonal. == See also ==