| Re: Envi Query [message #39591 is a reply to message #39516] |
Thu, 27 May 2004 04:24  |
guillem.soria
Messages: 3
Registered: May 2004
|
Junior Member |
|
|
Dear Chris,
Thank you very much for your help. We have used two methods to obtain
the lat/long of the pixels, firstly using the method that you describe
below (ENVI_CONVERT_FILE_COORDINATES) and secondly, on the advice of
RSI, exporting the data from a Region of Interest (ROI) to a text
file, which contains all the band information, map coordinates and
lat-long information.
However, we have some rather large discrepancies (around 0.005
degrees) between those lats and longs displayed in ENVI using the
cursor display facility, and those that result from our own extraction
procedures ( including the ROI values exported from ENVI!). The map
coordinates (in m) appear to be identical in all instances, suggesting
that the problem is constrained to the convertion of map coordinates
to geographic latitudes and longitudes.
If you have any advice on this issue we would be most grateful.
Many thanks,
Lizzie Noyes & Guillem Soria
On 26 May 2004 03:55:35 -0700, c_jengo@hotmail.com (Chris Jengo)
wrote:
> You could use ENVI_GET_PROJECTION to get the lat/lon of pixel (1,1),
> and the pixel size, then figure from there. Or you could feed
> ENVI_CONVERT_FILE_COORDINATES a big array of image indices. Write the
> results to a file (two bands, one for lat, one for lon), create a
> header using ENVI_SETUP_HEAD, and you're good to go. Let me know if
> you need more detail.
>
> Chris
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
