Hi all, i am experimenting problems writing a code to georeference MODIS DATA.

I copy and paste the code “example_glt_usage” from ENVI help in the IDL soft 6.2, I change the "[ ]", and I compile and run the code, then I select the images and next the runtime halt with the message error:
“envi_built_glt_doit: An error has occurred during processing”

Error: “Attempt to subscript DXS with is out of range.” The result may be invalid.
 
Some one experimented these error? I attach the code in the bottom..
thanks,
Javier
 
pro modis_geop1, ev

;compile_opt strictarr 

 

;  Select an image and it's associated input geometry. 

envi_select, title='Please select an image to georeference', $ 

   dims=dims, fid=fid, pos=pos 

if fid eq -1 then return 

envi_select, title='Please select the longitude band', $ 

   fid=x_fid, dims=dims, pos=x_pos, /band_only, /no_dims 

if x_fid eq -1 then return 

envi_select, title='Please select the latitude band', $ 

   fid=y_fid, dims=dims, pos=y_pos, /band_only, /no_dims 

if y_fid eq -1 then return 

 

;  Figure out what UTM zone we're in. 

;query_dims = [-1L, long(dims[2]/2), long(dims[2]/2), long(dims[4]/2), long(dims[4]/2)] 

;lat_lon = [envi_get_data(fid=y_fid, dims=query_dims, pos=y_pos), $ 

;               envi_get_data(fid=x_fid, dims=query_dims, pos=x_pos)] 

;zone = fix(31.0 + lat_lon[1]/6.0) 

;south = (lat_lon[0] lt 0) 

 

;  Make the GLT. 

envi_file_query, fid, sname=sname 

out_name=sname+'_glt' 

pixel_size=1000.0D 

rotation=0.0 

i_proj = envi_proj_create(/geographic) 

o_proj = envi_proj_create(/geographic) 

envi_glt_doit, i_proj=i_proj, $ 

   o_proj=o_proj, out_name=out_name, $ 

   pixel_size=pixel_size, r_fid=glt_fid, $ 

   rotation=rotation, x_fid=x_fid, y_fid=y_fid, $ 

   x_pos=x_pos, y_pos=y_pos 

if glt_fid eq -1 then return 

 

;  Georeference the image from the GLT. 

out_name=sname+'_georef' 

envi_doit, 'envi_georef_from_glt_doit', fid=fid, $ 

   glt_fid=glt_fid, out_name=out_name, pos=pos, $ 

   subset=dims, r_fid=r_fid 

 

end