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NAME: CHECK_EXP_FACTOR_DUPS PURPOSE: This procedure reads the exposure factor file for a given date and then writes it back out, eliminating any duplicate entries. CATEGORY: EXPFAC CALLING SEQUENCE: CHECK_EXP_FACTOR_DUPS,Tel,YYMMDD INPUTS: Tel: String indicating the telescope, 'c1','c2','c3' Date: Date for which the exposure factors are wanted can be in either YYMMDD, MJD, or CDS time structure COMMON BLOCKS: EXP_FACTOR_ARRAY: The exposure facotor information for a given date. PROCEDURE: READ_EXP_FACTOR is called to readin the exposure factor file for the specified date. Then WRITE_EXP_FACTOR is called to write it back out. Note that READ_EXP_FACTOR eliminates duplicates. MODIFICATION HISTORY: Written by: RA Howard, NRL, 22 Feb 1998 @(#)check_exp_factor_dups.pro 1.1 02/22/98 :LASCO IDL LIBRARY
NAME: CHECK_MONEXP_DUPS PURPOSE: Check for duplicate entries in MONEXP data CATEGORY: LASCO EXPFAC CALLING SEQUENCE: CHECK_MONEXP_DUPS,Tel,Datea INPUTS: Datea: String giving the starting date, '980401' OPTIONAL INPUTS: Dateb: String giving the ending date, '980401'. If not present, then the ending date is the starting date. COMMON BLOCKS: MONEXP_DATA PROCEDURE: The MONEXP data file for the specified dates and all telescope are checked for duplicate entries by checking to see if two entries have the same time of exposure. If there are any duplicates then the file is rewritten using the latest MONEXP entry in the data file. EXAMPLE: To check a single date: CHECK_MONEXP_DUPS,'c3','980201' To check a range of dates: CHECK_MONEXP_DUPS,'c3','980201','980204' MODIFICATION HISTORY: Written by: RA Howard, NRL, 6 June, 1998 @(#)check_monexp_dups.pro 1.1 06/08/98 LASCO IDL LIBRARY
NAME:
COMPUTE_MONEXP_FACTORS
PURPOSE:
This procedure computes the exposure time correction factors
CATEGORY:
DATA_ANAL
CALLING SEQUENCE:
COMPUTE_MONEXP_FACTORS,Tel,Dtea,Dteb
INPUTS:
Tel: String giving the telesope name, eg. 'c1'
Dtea: String giving the starting date, eg, '960601'
Dteb: String giving the ending date, eg, '960607'
KEYWORD PARAMETERS:
PS: If set, create a postscript file
NOSAVE: If set, don't save the output factors
PR: If set, print out debug information
POL: If set, defines the polarizer position to use
FIL: IF set, defines the filter position to use
OUTPUTS:
None
SIDE EFFECTS:
Generates plot files
Writes the exposure correction factors to a file
RESTRICTIONS:
Only computes correction factors for the primary filter and
clear polarizer positions
PROCEDURE:
This procedure computes exposure time correction factors by comparing
the median intensities in various regions. A region is a group of
32x32 superpixels. The ratio of a given image to a reference image
is computed. The median of the median ratios of all the superpixels
in a region is computed. The time history of the region medians is
used to detrend (each region separately) the normal coronal variation
from the exposure time fluctuations. Then the average of all the
detrended region ratios is computed to form the overall correction
factor for each image.
The detrending fits the 11 images before and after the time of the
desired image to a 2nd degree polynomial. No correction is made for
irregular timings.
The offset bias is divided by the on-chip summing to account for th
improper handling of the summing during the generation of the
MONEXP data. There, since the bias wasn't really known, the summed
pixel intensity was just divided by the number of summed pixels. This
division should have been done afer the bias was subtracted. The
computation was correct for LEB summing.
CALLED PROCEDURES
COMPUTE_MONEXP_POLY
COMPUTE_MONEXP_RATIO
OFFSET_BIAS
WRITE_EXP_FACTOR
READ_MONEXP_DATA
GET_MONEXP_DATA
STR_UNIQUE
MODIFICATION HISTORY:
Written, RA Howard and JS Morrill, Aug 1997
26 Feb 1998 RAH Make the calculations double precision
@(#)compute_monexp_factors.pro 1.11 06/04/98 LASCO IDL LIBRARY
NAME:
COMPUTE_MONEXP_POLY
PURPOSE:
This procedure fits a polynomial to the input monexp ratios to
obtain a set of exposure time correction factors
CATEGORY:
DATA_ANAL
CALLING SEQUENCE:
Result=COMPUTE_MONEXP_POLY(Dte,Ratio)
INPUTS:
Dte: Array of CDS date structure
Ratio: Array of image ratios
OUTPUTS:
The function result is the exposure factor for each image
RESTRICTIONS:
NONE
PROCEDURE:
This procedure computes the exposure time correction factors. It first
performs an 11 pointed median filter to the image ratios of a given region.
Then it fits a 2nd degree polynomial to the 9 points on either side of the
image time desired. TAI time is used as the independent variable in the
polynomial curve fit. No correction for any irregular spacing in the image
times is made.
The exposure time correction factor is the observed ratio divided by the
detrended, desired ratio. Thus it should be multipled by the exposure time
to obtain the corrected exposure time.
Plots are made of the fitted and observed factors.
MODIFICATION HISTORY:
Written, RA Howard and JS Morrill, Aug 1997
1/6/2001 RAH FOR loop changed from nw to nt, to include all points
@(#)compute_monexp_poly.pro 1.8 01/06/01 LASCO IDL LIBRARY
NAME:
COMPUTE_MONEXP_RATIO
PURPOSE:
This procedure computes the region ratios
CATEGORY:
DATA_ANAL
CALLING SEQUENCE:
Result=COMPUTE_MONEXP_RATIO(Medimg,Medref)
INPUTS:
Tel: String denoting the telescope
Medimg: Median image (32x32)
Medref: Median reference image (32x32)
OUTPUTS:
The function result is the ratio in each of the regions. The last
element of the array is the average of all regions.
RESTRICTIONS:
NONE
PROCEDURE:
Compute the ratios to the reference image for each region. Correct
for zero pixels in the reference image.
After computing the ratios, throw out those superpixels for which the
difference between the median and the observed ratio is greater
than 0.005. (This is an empirical number.) Compute the overall
average, median and standard deviation of the remaining superpixels.
For each region compute the median of the ratios for nonzero pixels.
If less than half of the superpixels have a ratio greater than zero, then
set the median of the ratios to be 0. This will flag the region
to be bad when computing the overall average.
MODIFICATION HISTORY:
Written, RA Howard, JS Morrill, Aug 1997
@(#)compute_monexp_ratio.pro 1.11 02/26/98 :LASCO IDL LIBRARY
NAME: COMPUTE_STD_VALS PURPOSE: This function computes the standard values over regions and other statistical information for monitoring the exposure value. CATEGORY: DATA_ANAL CALLING SEQUENCE: COMPUTE_STD_VALS,Img,Ihdr,Avgv,Sdev,Medn,Minv,Maxv,Nzero,Mode INPUTS: Img: The 2D image as read in by READFITS Ihdr: The image header in the LASCO structure OPTIONAL INPUTS: None KEYWORD PARAMETERS: None OUTPUTS: Nleb: Number of pixels being added together in the LEB Nccd: Number of pixels being added together on the CCD Avgv: Average intensity (1025 point floating array) Sdev: Standard deviation of the average (1025 point floating array) Medn: Median value (1025 point integer array) Minv: Minimum value (1025 point integer array) Maxv: Maximum value (1025 point integer array) Nzero: Number of zero values (1025 point integer array) Mode: Mode value (1025 point array) PROCEDURE: The image is expanded into a full 1024 x 1024 array to account for sub images. Also leb summing and on-chip summing are accounted for. The image is not normalized by the exposure time and the bias is not subtracted off. The average value, standard deviation, median value, minimum (non-zero) value, maximum value and the number of zero pixels in each block are computed. An array is generated of the six quantities for the entire array and then the 1024 32x32 pixel blocks. Each quantity then has an array size of 1025 values. If the image is a subimage then the blocks outside of the subimage would have zero values for the number of zeros. EXAMPLE: To compute the exposure monitoring information: COMPUTE_STD_SUMS,img,hdr,avg,sd,med,minv,maxv,nz MODIFICATION HISTORY: Written by: R.A. Howard, NRL, 10/3/96 Modified: RAH, NRL, 2/20/96 All blocks Modified: J. S. Morrill, NRL, 4/8-10/96: Added Mode and exp times Modified: RAH, NRL, 9/23/97 Check for odd image readout size Modified: RAH, NRL, 5/24/98 Check for underscan pixels SCCS variables for IDL use @(#)compute_std_vals.pro 1.11 05/24/98 :NRL Solar Physics
NAME: CORRSUBIMAGE PURPOSE: This function determines the exposure time correction factor of a subimage CATEGORY: LASCO EXPFAC CALLING SEQUENCE: Result = CORRSUBIMAGE (Hdr) INPUTS: Hdr: Image header in LASCO structure format OUTPUTS: This function returns the exposure time correction factor. RESTRICTIONS: PROCEDURE: EXPMON data for images earlier and later in time to the input image are tested to see if they have blocks that overlap the input image. The images closest in time to the input image are used. To use this routine an image header containing the following structure components must be provided: readport,detector,mid_date,mid_time,lebxsum,lebysum The MONEXP data must have been read in for the desired dates MODIFICATION HISTORY: Written by: RA Howard, NRL, 01 Oct 1999 @(#)corrsubimage.pro 1.1 11/02/01 LASCO IDL LIBRARY
NAME:
CORR_ALLSUBS
PURPOSE:
This procedure computes the exposure time correction factors for
all subimages
CATEGORY:
DATA_ANAL
CALLING SEQUENCE:
CORR_ALLSUBS,Tel,Dtea,Dteb
INPUTS:
Tel: String giving the telesope name, eg. 'c1'
Dtea: String giving the starting date, eg, '960601'
Dteb: String giving the ending date, eg, '960607'
KEYWORD PARAMETERS:
POL: If set, defines the polarizer position to use
FIL: IF set, defines the filter position to use
OUTPUTS:
None
SIDE EFFECTS:
Writes the exposure correction factors to a file
PROCEDURE:
MODIFICATION HISTORY:
Written, RA Howard Oct 1999
@(#)corr_allsubs.pro 1.1 11/02/01 :LASCO IDL LIBRARY
NAME: DELETE_EXPFAC PURPOSE: This procedure deletes the exposure factor files between two dates. CATEGORY: LASCO Exposure Factor CALLING SEQUENCE: DELETE_EXPFAC,Tel,Dtea,Dteb INPUTS: Tel: The telescope: 'c1','c2,'c3','c4' Dtea: The starting date, can be either a string yymmdd, or the modified julian date, or the CDS time structure Dteb: The ending date, can be either a string yymmdd, or the modified julian date, or the CDS time structure SIDE EFFECTS: The files in $NRL_LIB/lasco/expfac/data/YYMM/tel+.... are deleted. MODIFICATION HISTORY: Written by: RA Howard, NRL, 2/1/98 @(#)delete_expfac.pro 1.2 02/04/98 LASCO IDL LIBRARY
NAME: EXP_CORR PURPOSE: This procedure modifies the header to give the correct exposure time and adds comments to give the old time and the correction factor. CATEGORY: LASCO EXPFAC CALLING SEQUENCE: EXP_CORR,Hdr INPUTS: Hdr: LASCO image header OUTPUTS: The image header is modified RESTRICTIONS: The LASCO image structure is required. PROCEDURE: MODIFICATION HISTORY: Written by: RA Howard, NRL, 2/6/98 @(#)exp_corr.pro 1.1 04/17/98 LASCO IDL LIBRARY
NAME:
GET_EXP_FACTOR
PURPOSE:
This function returns the exposure factor and bias for the
given image.
CATEGORY:
EXPFAC
CALLING SEQUENCE:
Result = GET_EXP_FACTOR (Hdr,Exp_factor,Exp_bias)
INPUTS:
Header: Image header for which the factor and bias are wanted.
OUTPUTS:
Result: 0 for success,
-1 for file not found,
-2 for time not found.
Exp_factor: The exposure correction factor. It should be
multiplied with the exposure time to get the
correct time.
Exp_bias: The offset bias that should be subtracted from the
image.
OPTIONAL OUTPUTS:
Nreg: Number of regions that particpated in the calculation.
Exp_sig: The standard deviation in the fit.
KEYWORDS:
FITS_HDR STRARR = a FITS header, returned modified if set
COMMON BLOCKS:
EXP_FACTOR_ARRAY: The exposure facotor information for a given
date.
PROCEDURE:
The date in the image header is tested to see if the exposure factor
data in the common block are for that date. If not, the data are
then read in to the common block using READ_EXP_FACTOR. The data
are searched for the time of the exposure. If no time matches
the exposure, then the factor is set to 1 and the standard bias from
OFFSET_BIAS is used.
MODIFICATION HISTORY:
Written by: RA Howard, NRL, 21 September 1997
6 Oct 1997 RAH, Split away from READ_EXP_FACTOR
20 Feb 1998 RAH, Added the fits names to common
19 Jul 2000 NBR - Allow FITS header input, and add HISTORY to FITS header
1 Aug 2000 NBR - Add FITS_HDR keyword
7 Aug 2000 NBR - Remove FITS_HDR keyword
17 Sep 2002 NBR - Only use OFFSET_BIAS.pro if no expfactor; add filedate
to common block and FITS header
19 Sep 2002 NBR - Properly account for no expfac file found (2nd time through)
9 Jan 2003 NBR - Use fn instead of filenamenopath in header
EXAMPLE:
To obtain the exposure factor and bias information and then
convert the image counts to DN/sec:
success = GET_EXP_FACTOR(hdr,expfac,bias)
IF (success NE 0) THEN BEGIN
PRINT,'Exposure factor not found for image ',hdr.filename
PRINT,'Exposure factor is assumed to be 1.0'
ENDIF
img = (img-bias)/(hdr.exptime*expfac)
er= '@(#)get_exp_factor.pro 1.13 03/14/03' ;LASCO IDL LIBRARY
NAME: GET_MONEXP_DATA PURPOSE: This function returns the monitor data of datatype = type from the common block. CATEGORY: LASCO data analysis CALLING SEQUENCE: Result = GET_MONEXP_DATA(Type) INPUTS: Type: The data type to be returned OUTPUTS: This function returns an array of the image statistics generated for the exposure time evaluation for the datatype specified as the input parameter. COMMON BLOCKS: MONEXP_DATA: Contains the monexp data RESTRICTIONS: PROCEDURE: MODIFICATION HISTORY: Written by: RA Howard, 2 June 1997 @(#)get_monexp_data.pro 1.6 11/20/97 LASCO IDL LIBRARY
NAME: MONITOR_EXP PURPOSE: This procedure reads all the files for a given date and processes the image to give statistical information for exposure monitoring. CATEGORY: DATA_ANAL CALLING SEQUENCE: MONITOR_EXP,Date,Lz INPUTS: Date: Gives the date to be processed in one of the following formats: YYMMDD, 6 character string YYYY/MM/DD, 10 character string CDS Date Structure Long Word of the modified julian date Lz: 0 for Quick-look, 1 for Level-0 OPTIONAL INPUTS: Tel: The telesope designation (string): c1, c2, c3, c4/eit The default is all three LASCO telescopes. KEYWORD PARAMETERS: None OUTPUTS: None. SIDE EFFECTS: Appends the information to files in $MON_EXP with the file name telstr_monexp_YYMMDD.dat, where telstr is a string denoting the telscope and YYMMDD are 6 digits giving the year, month and day of the data: eg. c1_monexp_961231.dat c2_monexp_961231.dat c3_monexp_961231.dat (records) in the .dat file. RESTRICTIONS: PROCEDURE: EXAMPLE: To process the exposure monitoring information for 1 Sep 1996 quick look data: MONITOR_EXP,'960901',0 or MONITOR_EXP,'1996/09/01',0 or MONITOR_EXP,mjd,0 or MONITOR_EXP,mjd.mjd,0 MODIFICATION HISTORY: Written by: R.A. Howard, NRL, 10/3/96 Modified by: J. S. Morrill, NRL, 4/8/97 Modified by: RAH, 5/22/97, error handling for missing directories Modified by: RAH, 5/22/97, split out loop to monitor_exp_img @(#)monitor_exp.pro 1.7 06/02/97 :NRL Solar Physics
NAME: MONITOR_EXP_IMG PURPOSE: This procedure reads the specified file and processes the image to give statistical information for exposure monitoring. CATEGORY: DATA_ANAL CALLING SEQUENCE: MONITOR_EXP_IMG,Fn INPUTS: Fn: String containing the file name to process KEYWORD PARAMETERS: SAVEDIR Specify directory to save output to besides $MON_EXP OUTPUTS: None. SIDE EFFECTS: Appends the information to files in $MON_EXP with the file name telstr_monexp_YYMMDD.dat, where telstr is a string denoting the telscope and YYMMDD are 6 digits giving the year, month and day of the data: eg. c1_monexp_961231.dat c2_monexp_961231.dat c3_monexp_961231.dat (records) in the .dat file. RESTRICTIONS: PROCEDURE: EXAMPLE: To process the exposure monitoring information for the image specified by 120050001.fts: MONITOR_EXP_IMG,'120050001.fts' MODIFICATION HISTORY: Written by: R.A. Howard, NRL, 10/3/96 Modified by: J. S. Morrill, NRL, 4/8/97 Modified by: RAH, 5/22/97, error handling for missing directories RAH 5/24/97, Extracted from MONITOR_EXP to be able to handle single images NBR 1/10/01, Extract filename from input NBR 1/15/02, Add SAVEDIR keyword; convert nleb and nccd to type LONGWORD @(#)monitor_exp_img.pro 1.3 01/15/02 :NRL Solar Physics
NAME: PLOT_EXP_FACTOR PURPOSE: This procedure reads all the files for the given date range and plots the exposure time factors CATEGORY: EXP_FAC CALLING SEQUENCE: PLOT_EXP_FACTOR,Tel,Dtea INPUTS: Tel: The telesope designation (string): c1, c2, c3, c4/eit The default is all three LASCO telescopes. Dtea: Gives the date to be processed in one of the following formats: YYMMDD, 6 character string YYYY/MM/DD, 10 character string CDS Date Structure Long Word of the modified julian date OPTIONAL INPUTS: Dteb: Gives the final date to be processed in the same format as DteA KEYWORD PARAMETERS: PS: If set then the plot is sent to the printer, else it is sent to the current graphics device OUTPUTS: None. RESTRICTIONS: PROCEDURE: EXAMPLE: MODIFICATION HISTORY: Written by: R.A. Howard, NRL, 10/7/97 @(#)plot_exp_factor.pro 1.2 10/07/97 :LASCO IDL LIBRARY
NAME:
PLOT_MONEXP_STD
PURPOSE:
This procedure reads in the output data file from MONITOR-EXP.PRO,
and makes standard plots
CATEGORY:
DATA_ANAL
CALLING SEQUENCE:
PLOT_MONEXP_STD,Tel,Dtea,Dteb
INPUTS:
Tel: String giving the telesope name, eg. 'c1'
Dtea: String giving the starting date, eg, '960601'
Dteb: String giving the ending date, eg, '960607'
KEYWORD PARAMETERS:
PS: If set, create a postscript file
OUTPUTS:
None
SIDE EFFECTS:
Generates plot files
RESTRICTIONS:
NONE
PROCEDURE:
MODIFICATION HISTORY:
@(#)plot_monexp_std.pro 1.2 09/26/97 LASCO IDL LIBRARY
NAME:
READ_EXP_FACTOR
PURPOSE:
This function reads the exposure factor file for a given date
CATEGORY:
EXPFAC
CALLING SEQUENCE:
Result = READ_EXP_FACTOR(Date)
INPUTS:
Tel: Telescope (string: 'c1','c2','c3')
Date: Date for which the exposure factors are wanted, either
in YYMMDD, MJD, or CDS time structure formate
OUTPUTS:
Result: 0 = Successful read
-1 = File not found
COMMON BLOCKS:
EXP_FACTOR_ARRAY: The exposure facotor information for a given date.
PROCEDURE:
Called by GET_EXP_FACTOR
The file for the image date specified in the image header is
read into the common block.
The format in the exposure factor file is:
fname tsnnnnnn.fts (a12)
factor number (f10.6)
bias number (f10.1)
date YYMMDD (a6)
time SEC.MM (12.2)
Filter string (a12)
Polarizer string (a12)
Wavelength NNNN.NNNN (a9)
Nregion NNNN (i4)
Sigma NNNN.NNNN (f10.2)
Checks for duplicate entries and only saves the last one read in.
MODIFICATION HISTORY:
Written by: RA Howard, NRL, 21 September 1997
6 October 1997 RAH, Split read away from GET_EXP_FACTOR
20 Feb 98 RAH, added fits filenames to the common block
and changed the variable name to be nregion instead
of nzero
22 Feb 98 RAH, check for duplicate entries, and permit any format
for date
4 Dec 01 Use FILEPATH for filename
17 Sep 02 Add filedate to common block, from file_date_mod
@(#)read_exp_factor.pro 1.12, 09/18/02 :LASCO IDL LIBRARY
NAME: READ_MONEXP_DATA PURPOSE: This procedure reads in the MONEXP data for the given telescope and date. CATEGORY: LASCO data analysis CALLING SEQUENCE: READ_MONEXP_DATA,Tel,Dtea,Dteb INPUTS: Tel: String giving the telescope: C1, C2, C3 Dtea: First date to be read in, either YYMMDD, or MJD or UTC Dteb: Last date to be read in, either YYMMDD, or MJD or UTC KEYWORD PARAMETERS: NOSORT: If set then the MONEXP data are not sorted by time. The default is to sort the data OUTPUTS: Stores data into the common array COMMON BLOCKS: MONEXP_DATA SIDE EFFECTS: Reads in the data files of the form, $MON_EXP/cx_monexp_yymmdd.dat where cx is c1, c2, c3, or c4 and yymmdd is the year, month, day RESTRICTIONS: PROCEDURE: MODIFICATION HISTORY: Written by: RAHoward, NRL, June 2 1997 Modified: 11/11/97 RAH Check to see if MON_EXP file exists 06/06/97 RAH Added nosort option, check for nrec=0 12/18/98 RAH Added check for compressed files @(#)read_monexp_data.pro 1.9 01/15/02 LASCO IDL LIBRARY
NAME: WRITE_EXP_FACTOR PURPOSE: This procedure writes out a exposure factor record CATEGORY: LASCO EXPFAC CALLING SEQUENCE: WRITE_EXP_FACTOR,Tel,Fname,Fac,Bias,Date,Filt,Polr,Wavelen,Nz,Sigma INPUTS: Tel: String denoting the telescope, c1,c2, c3 Fname: String giving the filename of the image for which the factor was computed Fac: Exposure correction factor Bias: Offset bias Date: The date of observation as MJD or CDS time structure Filt: Filter wheel position (string) Polr: Polarizer wheel position (string) Wavelen:If C1 then the FP wavelength, else 0 Nz: The number of non-zero regions Sigma: Standard deviation of the computation of the expsoure factor OUTPUTS: Nothing is returned to the calling program. A record is written to the appropriate exposure time file. PROCEDURE: This routine is a subroutine to the expsoure factor determination and is not intended to be used separately. Write information to the exposure factor file in the following format filename tsnnnnn.fts (a12) factor number (f10.6) bias number (f10.1) date YYMMDD (a6) time SSSS.mmm (f10.2) Filter 0-4 (a12) Polarizer 0-4 (a12) Wavelength NNNN.NNNN (a9) Nz NNNN (i4) sigma NNNN.NNNN (f10.2) MODIFICATION HISTORY: Written by: RA Howard, Sep 1997 3 Feb 98 RAH, Make sure subdirectory exists @(#)write_exp_factor.pro 1.7 11/16/99 LASCO IDL LIBRARY
lasco_mk_html_help.pro on
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