| Re: How to build ASCII File [message #57031 is a reply to message #56972] |
Wed, 28 November 2007 13:37  |
Marshad2
Messages: 15
Registered: July 2007
|
Junior Member |
|
|
On Nov 24, 11:33 am, "devin.wh...@gmail.com" <devin.wh...@gmail.com>
wrote:
> I see what you're trying to do, but there's definitely an easier way
> to go about it. You're attempting to create a binary ENVI Spectral
> Library file that contains the spectral response curves for MASTER's
> first 25 channels (VNIR and SWIR) from the individual SRF ASCII
> files. Because of how ENVI Spectral Library files are constructed, an
> entry for a particular channel must contain response values for the
> entire wavelength range of the 25 channels, combined--even if the
> recorded values for a channel (in a single SRF file) fall over a much
> smaller range. As a result, you have to provide "filler" values of 0
> to compensate. Because each SRF file covers a different range and
> contains a variable number of entries, getting everything into one
> ENVI Spectral Library file is a bit challenging. The program below
> will build the library for you, as long as all of the individual SRF
> files and the associated header file (*.ph) are in the same folder on
> your computer. It makes liberal use of array and structure
> concatenation, subscripting, and the WHERE function to build the
> library. SORT is used in a few places to ensure that all response
> values end up in the right locations. The program is provided as is.
>
> pro create_master_spectral_reponse_sli
> compile_opt idl2
>
> header_file = dialog_pickfile(title='Select Spectral Response Header
> File', filter='*.ph', $
> get_path=header_path)
> if header_file eq '' then return
> out_name = dialog_pickfile(title='Select Output Library Name',
> path=header_path)
> if out_name eq '' then return
>
> spec_search = file_search(header_path, '*.c*', count=spec_count)
> if spec_count ne 50 then begin
> ok = dialog_message('You must have all 50 MASTER spectral response
> curve files to proceed', $
> /error)
> return
> endif
>
> ;Sort response files from lowest to highest band
> spec_sort = sort(spec_search)
> spec_search = spec_search[spec_sort]
>
> envi_read_cols, header_file, parameters
>
> band_nums = lindgen(25)+1
> band_names = replicate('Band',25) + ' ' + strtrim(string(band_nums),
> 2)
>
> ;Read in spectral response files and create
> ;structure array to hold all returned info
> spec_struct = {sensor_type:'MASTER'}
> wl_array = dblarr(1)
> for i=0,24 do begin
> envi_read_cols, spec_search[i], spec_data
> spec_struct = create_struct(spec_struct, band_names[i], spec_data)
> wl_array = [wl_array, reform(transpose(spec_data[0,*]))]
> endfor
>
> wl_array = wl_array[1:*]
> wl_array = wl_array[sort(wl_array)]
> num_measure = n_elements(wl_array)
>
> openw, lun, out_name, /get_lun
>
> ;Write out band-specific spectral response library entries
> for j=1,25 do begin
> cur_wl = (spec_struct.(j))[0,*]
> sort_cur = sort(cur_wl)
> num_cur = n_elements(cur_wl)
> where_cur = where(wl_array eq cur_wl[sort_cur[0]], where_count)
> response = reform((spec_struct.(j))[1,sort_cur])
> response_array = dblarr(num_measure)
> response_array[where_cur[0]:(where_cur[0]+num_cur-1)] = response
> writeu, lun, response_array
> endfor
>
> free_lun, lun
>
> file_type=envi_file_type('ENVI Spectral Library')
> envi_setup_head, fname=out_name, data_type=5, file_type=file_type, $
> interleave=0, nb=1, ns=num_measure, $
> nl=25, wl=wl_array, /write, /open, r_fid=lib_fid, $
> wavelength_unit=0, spec_names=band_names
>
> end
>
> On Nov 20, 12:19 pm, Marsh...@gmu.edu wrote:
>
>
>
>> Hi Guys:
>
>> I tried to make ASCII file for Spectral Response Curves obtained atftp://asapdata.arc.nasa.gov/MASTER/srf/May_03/however, it is not
>> working. Can someone give suggestions how to build ASCII file for
>> Spectral Response Curves.
>
>> Best Regards,
>
>> Arshad- Hide quoted text -
>
> - Show quoted text -
Thank You, Devin White. I really appreciate your respose.
Arshad
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
