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Re: overlying data on an image

Jairo Santana <santana@icesat2.gsfc.nasa.gov> writes:

> I have a grid of elevation heights in geo coordinates. Also I have
> points:
> lats, lons, heights. I need to plot the lats, lons, and heights on top
> of the grided image. How can I do that? Do I need to grid the data
> points (lat,lon,h) first? any suggestion/code will help.

Short answer (for a hypothetical image from long 30 to 40, lat 15 to 25)
  plotimage, img, imgxrange=[30,40], imgyrange=[15,25]
  oplot, lon, lat, psym=1

This will overlay the (LON,LAT) symbols on a flat cartesian image map.
You will probably also want to use the RANGE keyword to scale your
image into a 0-255 range.

I think this is what you want.  If you need to plot as a 3d relief
surface, then you should investigate the SURFACE command.  Liam Gumley
also makes a procedure called IMDISP, but I'm not sure if he can
overlay a coordinate system.


Download PLOTIMAGE from:
http://cow.physics.wisc.edu/~craigm/idl/idl.html   (under graphics)

Craig B. Markwardt, Ph.D.         EMAIL:    craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response