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;                                                                         ;
;           program read_pr-2_lev1b_hdf.pro                                    ;
;                                                                         ;
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;
; PURPOSE:     An IDL Procedure for reading a JPL PR-2 data file. 
; DATA FORMAT: Please refer to "User's guide to CAMEX-4 PR-2 data" for 
;              details.
;
;Copyright (C) 2002, California Institute of Technology. U.S. Government
;Sponsorship under NASA Contract NAS7-1270 is acknowledged.
;
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pro read_pr-2_lev1b_hdf, filen, zhh_ku, ldr_ku, vel_ku, zhh_ka, $
         look_vector, range0, isurf, sequence, vsurf, $
         vsurfdc8, no_av, fileheader, scantime, alt_r, lat, lon


; Open the file for read and initialize the Vdata interface
    file_handle = hdf_open(filen,/read)

; get the fileheader Vdata
    vdata_ID = hdf_vd_find(file_handle,'fileheader')
    vdata_H = hdf_vd_attach(file_handle,vdata_ID)
    hdf_vd_get,vdata_H,name=name,fields=raw_field
    nscan = hdf_vd_read(vdata_H, fileheader)
    hdf_vd_detach, Vdata_H

; get the scantime vdata
    vdata_ID = hdf_vd_find(file_handle,'scantime')
    vdata_H = hdf_vd_attach(file_handle,vdata_ID)
    nscan = hdf_vd_read(vdata_H, scantime)
    hdf_vd_detach, Vdata_H

; get the alt_r vdata
  vdata_ID = hdf_vd_find(file_handle,'alt_r')
    vdata_H = hdf_vd_attach(file_handle,vdata_ID)
    nscan = hdf_vd_read(vdata_H, alt_r)
    hdf_vd_detach, Vdata_H

; Find the scantime vdata
    vdata_ID = hdf_vd_find(file_handle,'lat')
    vdata_H = hdf_vd_attach(file_handle,vdata_ID)
    nscan = hdf_vd_read(vdata_H, lat)
    hdf_vd_detach, Vdata_H

; Find the scantime vdata
    vdata_ID = hdf_vd_find(file_handle,'lon')
    vdata_H = hdf_vd_attach(file_handle,vdata_ID)
    nscan = hdf_vd_read(vdata_H, lon)
    hdf_vd_detach, Vdata_H

; Close the hdf file
    hdf_close,file_handle   


; Initialize the scientific data set interface (hdf_sd* routines) 
    sdsfileid = hdf_sd_start(filen,/read)

    sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'zhh14'))

    hdf_sd_getdata, sds_id, zhh_ku

    sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'ldr14'))
    hdf_sd_getdata, sds_id, ldr_ku   

    sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'vel14'))
    hdf_sd_getdata, sds_id, vel_ku

ka_begin= fileheader(16)
ka_end  = fileheader(17)
if( (ka_begin ge 0) and (ka_end gt ka_begin) ) then begin
 sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'zhh35'))
 hdf_sd_getdata, sds_id, zhh_ka
endif
  
 sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'look_vector'))
 hdf_sd_getdata, sds_id, look_vector

    sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'range0'))
    hdf_sd_getdata, sds_id, range0

    sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'isurf'))
    hdf_sd_getdata, sds_id, isurf
 
    sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'sequence'))
    hdf_sd_getdata, sds_id, sequence

    sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'v_surf'))
    hdf_sd_getdata, sds_id, vsurf
    
    sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'v_surfdc8'))
    hdf_sd_getdata, sds_id, vsurfdc8
    
    sds_id = hdf_sd_select(sdsfileid,hdf_sd_nametoindex(sdsfileid, 'no_av'))
    hdf_sd_getdata, sds_id, no_av

    hdf_sd_end, sdsfileid

    return
    end