2025-09-05 09:42:21 +02:00

194 lines
6.0 KiB
Prolog
Executable File

PRO read_sst, Files, NumObs=NumObs, $
Latitudes=Latitudes, Longitudes=Longitudes, $
ObsSST=ObsSST, ModSST=ModSST, SSTQC=SSTQC, $
Dates=Dates, rmdi=rmdi, Types=Types, iobs=iobs, jobs=jobs, $
quiet=quiet
;------------------------------------------------------------
;IDL program to read in netcdf files of altimeter data.
;
;Author: D. J. Lea - Feb 2008
;
;------------------------------------------------------------
rmdi = -99999.
NumFiles=n_elements(Files)
;print,NumFiles
;RefDate = '1950-01-01'
;!DATE_SEPARATOR='-'
RefDate=JULDAY(1,1,1950,0,0) ; should be at 0 UTC
ifile2=0
for ifile = 0, NumFiles-1 do begin
;------------------------------------------------------------
;1. Open the file containing the data
ncid = ncdf_open(Files(ifile), /nowrite)
if ncid lt 0 and not keyword_set(quiet) then print, 'Error opening file '+Files(ifile)
if ncid ge 0 then begin
if not keyword_set(quiet) then print, 'Opened file '+Files(ifile)+' successfully'
;------------------------------------------------------------
;2. Read in the dimensions in the file
ncinfo = ncdf_inquire(ncid)
if ncinfo.Ndims eq 1 then begin
ncdf_diminq, ncid, 0, name, NData
endif else if ncinfo.Ndims eq 2 then begin
ncdf_diminq, ncid, 1, name, NData
if (name eq "string8") then ncdf_diminq, ncid, 0, name, NData
endif else if ncinfo.Ndims eq 3 then begin
ncdf_diminq, ncid, 1, name, NLats
ncdf_diminq, ncid, 2, name, NLons
NData = NLats * NLons
endif
if not keyword_set(quiet) then print, 'Number of SST data points ',NData
if (NData gt 0) then begin
;------------------------------------------------------------
;3. Allocate the data arrays and read in the data
lons = dblarr(NData)
lats = dblarr(NData)
obsval = fltarr(NData)
modval = fltarr(NData)
bytQC = bytarr(NData)
QC = fltarr(NData)
obstyp = intarr(NData)
Dats = dblarr(NData)
dts = replicate(!dt_base, NData)
iobsa = intarr(NData)
jobsa = intarr(NData)
varid = ncdf_varid(ncid, 'LONGITUDE')
if varid ne -1 then ncdf_varget, ncid, varid, lons $
else begin
varid = ncdf_varid(ncid, 'lon')
ncdf_varget, ncid, varid, lons
endelse
varid = ncdf_varid(ncid, 'LATITUDE')
if varid ne -1 then ncdf_varget, ncid, varid, lats $
else begin
varid = ncdf_varid(ncid, 'lat')
ncdf_varget, ncid, varid, lats
endelse
varid = ncdf_varid(ncid, 'JULD')
if varid ne -1 then begin
ncdf_varget, ncid, varid, Dats
dts=RefDate + Dats
endif else begin
varid = ncdf_varid(ncid, 'time')
ncdf_varget, ncid, varid, secs_from_base
varid = ncdf_varid(ncid, 'sst_dtime')
ncdf_varget, ncid, varid, dtime
ncdf_attget, ncid, varid, 'scale_factor', scale_factor
dtime=dtime*scale_factor
; RefDate = '1981-01-01'
RefDate = JULDAY(1,1,1981,0,0) ; should be ref from 0 UTC
dtime = dtime + secs_from_base
dts = RefDate + dtime/86400.
endelse
varid = ncdf_varid(ncid, 'SST')
if varid ne -1 then begin
ncdf_varget, ncid, varid, obsval
obsval=float(obsval) ;ensure obsval is a floating point array
ncdf_attget, ncid, varid, '_FillValue', FillValue
pts = where(obsval eq FillValue, count)
if count gt 0 then obsval(pts) = rmdi
endif else begin
varid = ncdf_varid(ncid, 'sea_surface_temperature')
ncdf_varget, ncid, varid, obsval
obsval=float(obsval) ;ensure obsval is a floating point array
ncdf_attget, ncid, varid, '_FillValue', FillValue
ncdf_attget, ncid, varid, 'add_offset', Offset
ncdf_attget, ncid, varid, 'scale_factor', Scale
pts = where(obsval ne FillValue, count)
if count gt 0 then obsval(pts) = Offset + (obsval(pts) *Scale)
pts = where(obsval eq FillValue, count)
if count gt 0 then obsval(pts) = rmdi
endelse
varid = ncdf_varid(ncid, 'SST_Hx')
if varid ne -1 then begin
ncdf_varget, ncid, varid, modval
ncdf_attget, ncid, varid, '_FillValue', FillValue
pts = where(modval eq FillValue, count)
if count gt 0 then modval(pts) = rmdi
endif
varid = ncdf_varid(ncid, 'SST_QC')
if varid ne -1 then begin
ncdf_varget, ncid, varid, bytQC
ncdf_attget, ncid, varid, '_FillValue', FillValue
QC(*) = 0.
pts = where(bytQC eq FillValue, count)
if count gt 0 then QC(pts) = rmdi
pts = where(bytQC ne 48, count)
if count gt 0 then QC(pts) = bytQC(pts)-48
endif else begin
varid = ncdf_varid(ncid, 'confidence_flag')
ncdf_varget, ncid, varid, bytQC
QC = float(bytQC)
endelse
varid = ncdf_varid(ncid, 'SST_DATA_SOURCE')
if varid ne -1 then ncdf_varget, ncid, varid, obstyp $
else begin
varid = ncdf_varid(ncid, 'data_source')
if varid ne -1 then ncdf_varget, ncid, varid, obstyp
endelse
varid = ncdf_varid(ncid, 'callsign')
if varid ne -1 then begin
ncdf_varget, ncid, varid, callsign
tmp=strtrim(string(obstyp),2)+' '+strtrim(string(callsign),2)
obstyp=tmp
endif else begin
varid = ncdf_varid(ncid, 'SST_CALL_SIGN')
if varid ne -1 then begin
ncdf_varget, ncid, varid, callsign
tmp=strtrim(string(obstyp),2)+' '+strtrim(string(callsign),2)
obstyp=tmp
endif
endelse
varid = ncdf_varid(ncid, 'IOBS')
if (varid ne -1) then ncdf_varget, ncid, varid, iobsa
varid = ncdf_varid(ncid, 'JOBS')
if (varid ne -1) then ncdf_varget, ncid, varid, jobsa
if ifile2 eq 0 then begin
Latitudes = [float(lats)]
Longitudes = [float(lons)]
ObsSST = [obsval]
ModSST = [modval]
SSTQC = [QC]
Dates = [dts]
Types = [obstyp]
iobs = [iobsa]
jobs = [jobsa]
endif else begin
Latitudes = [Latitudes, float(lats)]
Longitudes = [Longitudes, float(lons)]
ObsSST = [ObsSST, obsval]
ModSST = [ModSST, modval]
SSTQC = [SSTQC, QC]
Dates = [Dates, dts]
Types = [Types, obstyp]
iobs = [iobs, iobsa]
jobs = [jobs, jobsa]
endelse
ifile2=ifile2+1
endif
ncdf_close, ncid
endif
endfor ; ifile
NumObs = n_elements(Latitudes)
END