Identifier sws_rebin
Purpose Rebin an AAR onto a predefined grid or on a grid
defined by a constant resolution or constant binsize
Synopsis aar = sws_rebin( aar_in [, ref]
[, resolution=resol]
[, binsize=binsize]
[, oversample=oversample]
[, xrange=xrange]
[, aot_number=aot_number]
[, aot_speed=aot_speed]
[, aot_band=aot_band]
[, lines=lines]
[, scan=scan]
[, det=det]
[, /merge]
[, method=method]
[, minbin=minbin]
[, /nosmooth]
Arguments name I/O type description
--------------------------------------------------------------
aar O struct Rebinned spectrum in AAR format
aar_in I struct Input AAR
ref I struct Reference AAR containing an
'oversampled' wavelength grid.
SWS_REBIN checks on the definition
of AOT-bands, LINE and SCAN
resolution I fltarr Resolution to rebin the data to.
The defaults are resp. for
AOT 1 speed 1/2 3 4, AOT2/AOT6 or AOT7
default.
[default: 300/500/1000/1500/20000]
binsize I fltarr Constant binsize to which the AAR is
rebinned. Not used when RESOLUTION
has a nonzero value.
[No default]
oversample I int Oversample the spectrum.
[default: 4]
xrange I fltarr Full wavelength ranges of aot-bands as
in the reference aar or the data itself
aot_number I int Read from the AAR header.
On error AOT_NUMBER 1 is assumed.
[Default: yes]
aot_speed I int Determined from the header.
On error AOT_SPEED 4 is assumed
for AOT 1 else AOT_SPEED 0.
[Default: yes]
aot_band I strarr AOT-bands to rebin
Specifing 'NONE' will rebin the
full spectrum in one (usefull e.g.
for AAR's in which the status and
flag are undefined)
[Default: all aot-bands]
lines I intarr Lines, as defined in the AAR line tag.
LINES=0 combines all lines in a band
and assumes SCAN=0
[Default: all]
scans I intarr Scans, as defined in the AAR scnt tag.
SCAN=0 combines all scans.
[Default: all]
det I intarr Detectors to use.
/merge I keyword The data is first rebinned for
each AOT-band/line, after which
ovelapping regions are averaged.
method I string Method used to determine the
values in the rebinned spectrum.
'FLUXCON' : flux conserving rebinning
'MEAN' : plain average rebinning
'WMEAN' : weighted mean rebinning
'MEDIAN' : median binning
[default: 'FLUXCON']
weight I string Defines how the weighting for the
weighted mean rebinning should be done.
's' standard deviations (1/s^2)
't' integration time (sqrt(t_int))
'g' gaussian distribution with distance
of center of bin and fwhm of res
When combining options enter e.g. 'st'
[default: 's']
minbin I int minimum number of points required
[Default: 3]
nosmooth I keyword Do not smooth the data with a
gaussian of FWHM of the RESOLUTION
(only relevant with the FLUXCON option)
noplot I keyword Do not plot the spectrum.
Returns Rebinned spectrum in the form of an AAR
Description SWS_REBIN will rebin the input data onto a grid either
specified by the user or to a fixed resolution or binsize.
Only data not flagged as NODATA is used.
For resolution bins for which there is no data a warning
is issued. The values for these points are replaced by
interploated values and the FLAG is set to NODATA.
Default all AOT-band's, lines and scans are treated seperately.
When using /MERGE all AOT-bands/lines/scans are first
rebinned seperately and then combined afterwards.
AOT_BAND = 'NONE' will rebin all data
LINES = 0 will combine all lines and scans
SCANS = 0 will combine all scans
WMEAN gives a weighted average rebinned spectrum.
The weighting can be a combination of three items;
's' the standard deviation (1/(stdev^2))
't' integration time (sqrt(t_int))
'g' gaussian smoothing (with fwhm of the resolution)
The applied weight is the multiplication of the
individual weights. To use this enter a combination of
the characters, e.g. WEIGHT='s' (default) or WEIGHT='stg'.
Adding a character more times will add its weight
accordingly, e.g. WEIGHT='tt' or 'stt' will add the
weight for the integration time twice making the
effective weight for the integration time t_int instead
of sqrt(t_int).
FLUXCON implies flux conserving rebinning. For each bin
the flux value is calculated using the trapezoidal rule.
When using FLUXCON, the data is smoothed with a gaussian
with a FWHM of the resolution. /NOSMOOTH disables this.
Setting the IA error level to 'D' (debug) will give
the user information on e.g. the wavelength of the bin
and the number of points in the bin.
Plotted is the input data for each AOT-band/line and
and the rebinned spectrum.
Examples
It is possible to combine resolution and binsize
to rebin one band to a constant resolution and
another to a constant binsize, e.g:
aotbands=['1a','1b','1d','1e']
resol =[2000,1500,0 ,1200]
binsize =[0 ,0 ,0.003,0 ]
aar_reb=sws_rebin(aar, aot_band=aotbands, $
resol=resol, binsize=binsize)
Comments
Category UTIL
Filename sws_rebin.pro (module: sws_rebin)
Version 2.9
History 1.0 08-02-1996 FL document created
1.1 06-03-1996 FL error in auto range
1.2 25-03-1996 FL range->xrange, improved in speed
02-04-1996 FL variable 'wave' replaced by 'waves'
1.3 10-05-1996 FL rebin per line/aotband, add sigma
clipping and flux conserving rebinning
1.4 14-05-1996 FL proper date in history for v1.3,
improved procedures
1.5 14-05-1996 FL ignore line tag, removed small bugs
1.6 15-05-1996 FL error in sigma clipping, problems with
using INT_TABULATED -> call replaced
1.7 17-05-1996 FL checked plotrange, option 'none'
and check on NODATA
2.0 10-06-1996 FL SIGCLIP routine extracted, Gaussian
smoothing with FWHM of the res. bin.
2.1 17-06-1996 DRB not_enoug(0) -> not_enough(0)
2.2 04-07-1996 FL return noise in stdev (stdev/sqrt(no))
2.3 19-08-1996 FL /NOSMOOTH did not work
2.4 11-09-1996 FL SPR_S0056 and SPR_S0057, better colors
problems with AOT6s solved
2.5 15-09-1996 FL SPR_S0059 inproper binsize init with RESOL
2.6 28-11-1996 FL SPR_S0131 new interface to CHK_MULTIX
2.7 24-02-1997 FL SPR_S0189 correct line numbers,
correct FWHM with Gaussian.
2.8 05-09-1997 FL SPR_S0268 retain reference grid, also
with AOT-bands
SPR_S0267 correct use of line and scnt
2.9 25-09-1997 FL SPR_S0281 more efficient data selection
added WMEAN method
SPR_S0282, use rgb colors