SHORT EXPLANATION FOR THE CORRECT USE OF S055 FITS FILES by Mathieu HIRTZIG August 2001 TABLE OF CONTENT Apollo Telescope Mount: instrument S055 Introduction to SKYLAB S055 Content of the README_S055 folder Structure of the FITS files More precisions Structure of the data files Using the programs History of modifications ----------------------------------------- INTRODUCTION TO SKYLAB S055 Acquired from May 1973 to February 1974, the Harvard Skylab ATM S-055 extreme ultraviolet observations of the Sun are the most comprehensive data in existence prior to both CDS and SUMER on SOHO. They laid the foundation to our present day understanding of the dynamics of the Sun and the solar wind. One of the most outstanding characteristics of these data is that observations were made simultaneously through the same optical slit at up to seven wavelengths spanning temperatures characteristic of the chromosphere to the corona. Furthermore, the observations covered the whole range of solar features with many discovered during that mission, for example polar plumes, macrospicules, and sunspot plumes. Spectral scans of these features provided key physical information. In several ways these data are unique. Some of the spectral region studied has not been covered by any subsequent instrument. For some observations very high time resolution is possible (e.g. 5 sec in mirror "line scan" mode, 41 msec in mirror "stopped" mode). The simultantous acquisition of perfectly spatially aligned image data at different wavelengths is also unique. The coverage of such a large spectral width was assured by seven detectors (photomultipliers) whose bandpass were: det 1 1.6 Angstrom det 2 8.3 Angstrom (but an attenuator reduced its flux by a factor 2) det 3 4.0 Angstrom det 4 4.0 Angstrom det 5 8.3 Angstrom det 6 4.0 Angstrom det 7 4.0 Angstrom What follows is inspired by the S055/ATM Scientific User Tape Guide by H T Wadzinski and Data Handbook for the Harvard EUV Spectroheliometer on ATM by W Harby and E M Reeves. For further information, please refer to these booklets. ----------------------------------------- CONTENT OF THE README_S055 FOLDER This is the list of all the files you can find in this folder. A short description of each item is added. Please note that every CD has the same folder written on it. README what you're reading ATMCATALOG a list of the ID records per file per tape FINALCOPY.TXT a list of the DOY/DLC/topic per DLC FINALCOPY2.TXT another version of the former file ATMLIB.C library of F77 routine used for ATM ATMLIB.O the same library in another format ATMAUTO.F called by MAKING_FITS_FROM_TAPE.pro MODIFY_FITS.PRO to modify the header of the S055 FITS files QUICK_S055.PRO quick look for Raster and Linescan mode MAKING_FITS_FROM_TAPE.PRO transforms the raw data into FITS AUTOMATE.PRO lists and treats every FITS in one directory INDEX_S055.TXT the index of all the files COMPLETE_LIST.TXT a merging of FINALCOPY and ATMCATALOG S055_POINTING.FIG a figure illustrating the pointing calculations S055_POINTING.GIF the same figure in another format LIST_CD.TXT a list of the DOYs per CD RASTER.GIF explains how one raster was made WAVE_TABLE?.GIF (5 files) gives the spectral lines visible at GRATPOS How to search these FITS files ? Search per topic: use "grep TOPIC finalcopy.txt" this will return several lines that can still be searched. Files are listed by SL#/DOY/DLC Search per type: use "grep TYPE index_S055.txt" or "ls *TYPE.fits" (where TYPE is R, L, G or S) in the directory. Files are listed by name Search per date: use "grep DATE index_S055.txt" (where DATE = "YYYY-MM-DD") Files are listed by name Search per SL#/DOY/DLC: use "grep X index_S055.txt" (where X = DOY or DLC or SL) Files are listed by name And so on. INDEX_S055.TXT contains the most comprehensive information, and should be used instead of ATMCATALOG or COMPLETE_LIST. The latter are given in case some files are missing. Furthermore, the subject of the images can only be found in FINALCOPY. The repartition of the FITS files per CD is to be read in LIST_CD. ----------------------------------------- STRUCTURE OF THE FITS FILES Name of the files: The name of the file has the same structure as SOHO data files, ie: ATM.YYMMDD.HHmmSS.X.fits X is the type of scientific data contained in the file. Some acronyms must be explained here: DOY= Day of Year; this is the number of the day, 1 being the 1973-01-01, 365 being 1973-12-31, 366 being 1974-01-01, and so on. DLC= Day Light Cycle; this is one revolution of the spacecraft on its orbit around Earth. It begins at the sunrise, witnesses the sunset about 100 minutes later, then ends after 50 minutes of night. GMT= Greenwich Meridian Time from 1973-01-01 at 00:00:00.000, usually in milliseconds. FSS= Fine Sun Sensor ENG1= Engineering data of type 1 ENG2= Engineering data of type 2 All the FITS files have two extensions. The main data cube corresponds to the scientific data The first extension corresponds to the engineering data of type 1 The second extension corresponds to the engineering data of type 2 There are 4 main modes that are displayed in the very name of the FITS file: R stands for Raster: the data form an image of 132x60 pixels, covering an area of 5x5 arcmin. The size of the data cube is fixed and equals 132x60x7 L stands for Linescan: the detector scans a strip (X) of the sun, and goes back and forth without moving Y: the result is a series of lines of 132 pixels, but the structure 132x60x7 is kept, Y being equivalent here to T (time). Indeed, it takes about 5.55 seconds for the detector to scan one line. G stands for Grating: the data form one or more spectra. The size of the data cube changes to fit the length of the grating, and will be noted Nx2x7. There's one Nx2 slice of data per detector. In fact, it is not an image but a couple of vectors: the first one gives the intensity, the other is the grating position (taken from Eng1), with can easily be related to wavelength. S stands for Stopped: neither the mirror nor the grating moves. But the structure is identical to the Grating mode data cube one. The extension ENG1 displays one line per second, and must be read as follow: example: 56561215 72 -31 25 60 11214 3154 3035 10277 5388 1 0 1 word 1: 56561215 = GMT in millisec of each chunk of data (checked every second) word 2: 72 = GAMY = FSS Y deplacement (arc-sec) from center of sun -31 = GAMX = FSS X deplacement (arc-sec) from center of sun 25 = LRBIA = X-bias for S082 from FFS 60 = UDBIA = Y-bias for S082 from FFS word 3: 11214 = time modulo 30 000 (millisec) 3154 = 20*(XPOS = X position on the grid (arc-sec)) 3035 = 20*(YPOS = Y position on the grid (arc-sec)) 10277 = GAMRR = roll of cannister in arc-minute word 4: 5388 = GRTPOS = grating steps (one step~0.21A) 1 = GRAT = grating code (0=STP, 1=GAS, 2=G3S, 3=REF, 4=SS) 0 = MIRR = mirror code (0=STP, 1=M3R, 2=MLS, 3=MAR) 1 = REFSEL = reference chosen (0=mechanical, 1=optical) The exact meaning of each code is explained later. The extension ENG2 displays one line every 1/24 of second, ie one per data point. Here is an example: 56561631 0 0 1 56561631 = time of each data 0 = OPTREF = optical reference hit (1) or not(0) 0 = End of Line or Raster (passes from 1 to 0 when line is finished) 1 = MCHREF = mechanical reference hit (1) or not(0) The third value is used only by Raster and Linescan mode: the EoL bit changes during 3 steps: for the last pixel of one line, and for the 2 first pixels of the following line. Explanation of the different codes used for the modes in ENG1: GRAT 0=STP Stopped mode: the grating does not move 1=GAS Grating Auto Scanned: the grating moves continuously, and will not stop until ordered to. 2=G3S three consecutive scans then stop at reference 3=REF one scan until reference is hit 4=SS Single Step: the grating moves by one step on command MIRR 0=STP Stopped mode: the mirror does not move 1=M3R three consecutive rasters then stop 2=MLS Mirror Line Scan: the Y position does not change, for the mirror rotates in only one direction. Thus on strip of Sun is scanned with a very high time resolution (one line takes about 5.5 sec) X is still a space coordinates, but Y on the images stands now for the time coordinate. 3=MAR Mirror Auto Raster: the mirror moves continuously, until stopped. This code (MIRR) is the one that conditions the format of the temporary files (such files are created by the very first program, DECIPHER_S055, and keep the ancient notations that can be found either in the ID record or in the explanatory booklets): if MIRR=0 then type S (as read in IDstring): Stopped or Spectrum if MIRR=2 then type L: Linescan if MIRR=1 or 3 then type R: Raster The second program (MAKING_FITS_FROM_TAPE) changes these codes into more useful ones, while it tranforms the temporary files into one FITS file: if MIRR=0 then type S (Stopped) or G (Grating) according to the average value of GRAT (this is explained a little later) if MIRR=1 then type R (Raster) if MIRR=2 then type L (Linescan) if MIRR=1 or 3 then type R (Raster) ----------------------------------------- FURTHER PRECISIONS Pointing Please refer to the figure S055_POINTING.FIG at the same time. What follows is a summary of the S055/ATM Scientific User Tape Guide by H T Wadzinski (p19) To calculate the position of some pixel in one image, you must check several values in several parts of the FITS file. *In the Eng1, the words 2.1 and 2.2 give the pointing of ATM_S082, with GAMY and GMAX. GAMRR (word 3.4 of Eng1) gives the rotation of the coordinates system. (GAMRR being positive means the rotation is clockwise) *Then you must consider the bias of S082 from S055. This is given in the words 2.3 and 2.4, with LRBIA and UDBIA. *A coalignment was checked from time to time, and it is NOT in the FITS file. You must instead use these values: SL DOY S82(+/-1) L82(+/-1) 2 143-218 32 8 3 218-330 32 9 4 331-346 32 10 4 346-410 33 10 *Finally, you have to specify which pixel you study: XPOS and YPOS (these are the words 3.2 and 3.3 of Eng1, but they're not really relevant for they were checked only once per second) As a conclusion, in the tilted system of coordinates centered on the sun, the pixel (S,L) is located at the point: Xsun = GAMX - LRBIA + (S-S82)x5" Ysun = GAMY - UDBIA - (L-L82)x5" These formulae give the position with a 5" accuracy. Notes: Here, S and L are used instead of XPOS and YPOS for their units are different: S is the step (ranges from 1 to 60 for the central part of the raster, ie for pixels of [7,126]), and L is the line number. One step or one line correpsonds to 5", so S and L are 5 times smaller than XPOS and YPOS. In a nutshell, the words 3.2 and 3.3 of Eng1 mean: word 3.2 = 3154 means S=31 (pixel #68) XPOS=157.7 arc-sec word 3.3 = 3035 means L=30 (line #30) YPOS=151.75 arc-sec Thus the formulae can be used with XPOS and YPOS: Xsun = GAMX - LRBIA + XPOS - S82x5" Ysun = GAMY - UDBIA - YPOS + L82x5" Warning: the line numbers decrease with Y ! hence the -1 in the second formula. Missing data and Filling data Missing data are scientific (or engineering) data that had been missing before the writing of the very tapes. This could have occurred during the transmission between the spacecraft and the ground antenna, for example. Such data are replaced in general by the value 2^14=16484. Filling data is an avatar of programs that can only return data in a very strict format. The program that permitted the writing of the Exabyte tapes is an example of such robotic program. The program that created these FITS files is a little more flexible, but it kept some rules (seven slices of data even if only ONE detector was ON) and it was often forced to keep its predecessor defaults. Thus, if one set of data was not long enough to fit in the program "box", this "box" was then filled with dummy data. The usual value of such filling data was either 32767 or -1. The FITS files should now only contain -1's in such cases. Errors and overflows The choice of the values used to flag the missing and filling data was led by the knowledge of the average values measured by the detectors: usually, this ranges from 10 to 800. So such a high value could obviously be the sign of some suspect data. Though, so high values could be reached by other means: -bright feature: some solar events (eg flares) can be really luminous, and thus can reach very high values. Sometimes, one (or even more) overflow could occur, giving a very different value in the image from the one seen by the detector. Adding 2^15 in such cases can be done by hand if it is deemed useful, by judicious comparison of neighboring data points which have not overflowed (although some care must be taken for detector non-linearities of detector-overflow data.) The Lyman spectral lines are some of the intense lines that could lead to such situations. -Voltage down: when one detector was given less than 50% of its operational voltage, the 15th bit was set on. This can explain that some values reach 16384. Furthermore, the detector was still working, and it would record the flux of photons it saw. But we do not know if the variations of 16400 +/- 20 can be easily related to the real incoming flux. -corruption of the data: this might be another explanation As a conclusion, care should be taken not to confuse the 2^14 bit of bright features with the voltage flag of suspect data. NVALID Because of the multiple causes of very high values, with some of them due to real events and not to technical alea, it has been difficult to check the state of the data. Nvalid (the number of valid data point per ON detector) should not be taken as reliable. In fact, this number only represents the number of pixels whose values were greater than 0 and less than 16 000 (to avoid both the flags of missing and filling data). But if a bright event is present, it will not be shown in NVALID. There is another way to notice that there was such a bright event: IBAR gives the average intensity of the "valid" pixels (here "valid" has the same meaning as formerly). But if there were a really luminous event, then IBAR should be quite high too, for it is very unlikely that the bright event reached an intensity of 20,000 while the surrounding zone stayed at 100. SDI (Standard Deviation of Intensity !WARNING! it is clearly not a percentage, as wrongly noted in the header) should then be very high too. On the other hand, very dark sets of data can have a very high NVALID, but be of limited interest. Two main cases appear: either the region scanned was very dim, or even off the limb, OR this could be Night Data! Night Data are set of data taken when the spacecraft was in Earth's shadow, and could not see the Sun. This is the case between each DLC, and the detectors were usually turned off during this time. But it was not always the case, so there are sets of data with a very high NVALID, but very low IBARs and SDIs. Once more: these are not always Night Data, and should be checked by hand! Finally, the last problem of NVALID is the one of every calculation of average values: if one detector had a problem (usually, det 5), its number of valid data will be low, while the other detectors may have complete sets of data. So, because of one ugly duckling, NVALID will drop. Differentiating Grating Scan (G) and Grating Stopped (S) modes: NVALID is not the only artificial information in these FITS files. The very classification of Grating/Stopped mode is really difficult to handle. The main common point between these two modes (what explains their similar structures) is that the mirror was not moving. A real Grating mode corresponds to the set of data taken when the grating was continuously moving. On the other hand, a Stopped mode occurs when the grating is not moving at all. But how should a file taken during a manual setup of the detectors be treated? This is the solution we've chosen: if the grating did not move during at least 90% of the length of the file, such a file would be called "Stopped". The other cases would be called "Grating". But it is not perfect. The way to study this was to calculate the average value of the non-(-1) figures from the 11th column of Eng1. Since the main modes of the grating were coded by either 1 (GAS) or 0 (STP), an average value of 0.1 would mean that there were 90% of 0s and 10% of 1s. But there were other modes: GRAT=2 was the G3S mode and GRAT=3 was the REF mode. These can be considered as Grating modes, even if they stop the grating at the end. But GRAT=4 was the SS mode: only one step of the grating, then stop. This is clearly not a grating, but one GRAT=4 with 39 instances of GRAT=0 is enough to have an average of 0.1 and thus this will be considered as a Grating! So, the main point is: always check your files before having them deleted automatically! Grating mode: Grating STEP, Grating POSITION and wavelength Please refer to the graph SPECTRUM.GIF at the same time. It shows the evolution of the Wavelength on Detector 1 as a function of motor steps. (the pattern is similar on each detector) In this example, everything is happening correctly, which may not always be the case. But first, some definitions are needed: Grating STEP or Motor Step, is a cumulative counter that ranges from 0 to 8191. It is reset whenever : 1-Mech Ref is selected and is hit 2-Opt REf is selected and is hit 3-it overflows after 8191 This value is the one inscribed in Eng1. Grating POSITION is a value that directly represent the position of the grating. When everything is right, GRATSTEP and GRATPOS are identical during the first part of the operation (see graph). But during the flyback, GRATSTEP will continue to increase, whereas GRATPOS will decrease to return from 5160 to 0. Wavelength is quickly related to GRATPOS, and we used a linear conversion, given in the booklet by Wadzinski, to provide the header with a nominal wavelength on each detector. Here they are (one equation per detector, the accuracy is 2 Angstroms) lambda1 = 1336.4 -0.2112*GRATPOS lambda2 = 1219.3 -0.2113*GRATPOS lambda3 = 1032.2 -0.2108*GRATPOS lambda4 = 977.4 -0.2111*GRATPOS lambda5 = 896.0 -0.2109*GRATPOS lambda6 = 625.6 -0.2090*GRATPOS lambda7 = 553.4 -0.2093*GRATPOS Of course, the lambdas should be checked by the recognition of well-known spectral lines. Optical reference: this normally chosen reference is hit when the zero order image from the grating strikes a white light detector. In such a position, all the detectors are in focus, and it is the principal position used for Rasters and Linescans. This reference, once hit, stays on during 35 steps. Mechanical reference: this reference is used when the OptRef cannot be (when pointing off the limb, for example). It is a lever that is pushed by the cam (commanding the moves of the grating) at the "launch lock" (see graph). This reference, once hit, stays on during about 600 steps. Known problems: at the very beginning of the mission, some spectra were done off the limb, but without selecting the MechRef. Thus, since the optical reference cannot be hit (there is no real zero order image), the GRATSTEP are not reset on usual occasions, so the counter continues to increase (modulo 8192) and does not have any direct link anymore with GRATPOS. So two solutions can be used. The first one, very easy when the spectra are in good state, is to guess the wavelength by extra- or interpolation with the wavelength of recognizable spectral lines. If it's not the case, the second way can be used. It is a very rough method, that cannot be really precise. At the STARTPNT (Starting Point, given in the Header), the reference is supposed to be hit. So the GRATPOS can be supposed to be 0 on this point. Then it takes about 5160 steps to complete a spectrum, so the launch lock can be supposed to occur on the (STARTPNT+5160)th point. The flyback roughly begins at the (STARTPNT+5465)th point, and is over 30 points later. This can be confirmed by the MechRef value (even if it was not selected, it was always working): it becomes 1 near the launch lock time, and should stay 1 till the end of the flyback (it should go off 250 points after the beginning of the next spectrum) But this method cannot be more accurate than 50 steps, ie the wavelengths are known with an accuracy of more than 10 Angstroms (more than the detectors bandpass). So, it should be used only in desperate cases. ----------------------------------------- STRUCTURE OF THE DATA FILES The raw data files all have the same structure: 1 record of length 180 ID record 1 to 3 records (len 4860) engineering data of type 1 1 to 24 records (len 3360) engineering data of type 2 1 to 30 records scientific data the length of these records depends on the type of data: 5010 for Grating/Stopped, 4950 for Raster or 4620 for Linescan ID record: here is an example 19431 17 53 1973 194 56566215 1 0 0 0 0 0 0 0 21 3 121 0 19431 = word 1 = magnetic band number 17 = word 2 = file number 53 = word 3 = site code (MSFC) or SL#*10^5+DLC (JSC) 1973 = word 4 = year 194 = word 5 = DOY 56566215 = word 6 = GMT start in millisec 1 0 0 0 0 0 0 = words 7>13 = detectors ON/OFF 0 = word 14 = storage mode (0=S 1=r 2=L 3=R) 21 = word 15 = total # of Eng1 + Eng2 records 3 = word 16 = total # of scientific records 121 = word 17 = pointer of starting point of the data 0 = word 18 = unused There were two centers that treated separately different sets of the data from SKYLAB: the Johnson Space Center and the Marshall Space Flight Center. Both of them chose different ways to handle the data, which can be seen in many places. Here is one: the content of the 3rd ID word. Other examples will be seen later. The word 4 is the storage mode used by DECIPHER_S055 to create temporary files: 0 = type S (as read in IDstring): Stopped or Spectrum 1 = type r (for Mini-Raster: a 1-minute long raster that could give a higher time resolution than the usual 5.5-minute mode) 2 = type L: Linescan 3 = type R: Raster The program MAKING_FITS_FROM_TAPE then chooses other notations that suit better to the content of the FITS data cube: 0 = type S (Stopped) or G (Grating) 1 = type R (Raster) 2 = type L (Linescan) 3 = type R (Raster) ID string: the programs usually transform the 18 words of the ID record into a more understandable string, like: 19431/017 194:15:42:46.215|121 1______ 3+18E,3S Carnarvon 19431/ = word 1 = magnetic band number /017 = word 2 = file number 194:15:42:46.215| = word 5+6 = DOY:HH:mm:SS:fff (fff=millisec) |121 = word 17 = pointer of starting point of the data 1______ = words 7>13 = detectors ON/OFF 3+18E, ~ word 15 = total # of Eng1 + Eng2 records ,3S = word 16+14 = total # of scientific data and storage mode (S L R or r) Carnarvon = word 3 = site (MSFC) or SL# + DLC The storage mode here is the same as in IDstring, so it is not the same as in the final names of the files. Again, HERE, S L R and r mean respectively Stopped or Spectrum, Linescan, Raster and Mini-Raster Eng1 records: One record correspond to 121 blocks of 4 words, plus at least 2 words of terminal fill. (JSC flagged all such bits on, while MSFC used them all off) Each block produces: word high order low order 1 milliseconds 2 GAMY GAMX LRBIA UDBIA 3 GMT XPOS YPOS GAMRR 4 GRTPOS MIRR GRAT REFSEL The meanings of these codes were already mentioned above, but they are repeated here for convenience: word 1: GMT = GMT in millisec of each chunk of data (checked every second) word 2: GAMY = Fine Sun Sensor Y deplacement (arc-sec) from center of sun GAMX = FSS X deplacement (arc-sec) from center of sun LRBIA = X-bias for S082 from FFS UDBIA = Y-bias for S082 from FFS word 3: GMT = time modulo 30 000 (millisec) XPOS = 20 times the X position on the grid (arc-sec) YPOS = 20 times the Y position on the grid (arc-sec) GAMRR = roll of cannister in arc-min (positive for clockwise) word 4: GRTPOS = grating steps (one step~0.21A) GRAT = grating code (0=STP, 1=GAS, 2=G3S, 3=REF, 4=SS) MIRR = mirror code (0=STP, 1=M3R, 2=MLS, 3=MAR) REFSEL = reference (0=mechanical, 1=optical) Eng2 records: One record corresponds to 336 words, one per 1/24 of second: 30 bits 10 bits 10 bits 10 bits GMT OptRef EoR/EoL MechRef Their meanings are: GMT = time of each data 0 = OPTREF = optical reference hit (1) or not(0) 0 = End of Line or Raster (passes from 1 to 0 when line is finished) 1 = MCHREF = mechanical reference hit (1) or not(0) The useful words were followed by terminal fill to fit this 336-word structure: all bits on (1) at JSC, or all off (0) at MSFC. Scientific records: The length of each record varies with its type, but its interpretation is quite different too. The Stopped and Grating modes are not treated in different ways, for both of them were considered 'non-moving mirror' data. Here are the meanings of the records for each type of file: R mode: One record corresponds to one quarter of image, ie one 132x15 block of data. These quarters are put together within a file, ignoring OFF detectors and creating only one quarter per image if these are less than 25% worth of data, creating 2 quarters if the images are less than 50% worth of data, and so on. There are at most 4 records per detector, so the maximum number of records is 24 L mode: One record corresponds to a set of 14 lines, 2 per detector, EVEN IF some detector is OFF. In such case, the 2 lines for the OFF detectors will be 264 occurences of 16384. There are at most 30 records per file (fixed format: 132pix x 60lines) S/G modes: one record corresponds to 2004 values (ie 83.5 seconds) only one detector at a time. One detector can produce up to 3 records per file, hence the maximum number of 21 records per file. ----------------------------------------- USING THE PROGRAMS The explanations lie in the files themselves, but for convenience they will be reported here. These are mainly IDL procedures, but one of them requires the use of a F77 program. So if you plan to use MAKING_FITS_FROM_TAPE, you must first run: "f77 -o decipher_s055 atmauto.f atmlib.o" ;+ ; NAME: ; MAKING_FITS_FROM_TAPE ;PURPOSE: ; Creates a FITS file from the raw data file of S055 ;EXPLANATION: ; Reads the IDrecord of the file and creates a Header ; Calls a special F77 routine "persobidule" to cut the file into precise pieces ; Decipher these pieces into understandable matrixes of data, then into a FITS file. ;CALLING SEQUENCE: ; Result = MAKING_FITS_FROM_TAPE( fname ) ;INPUTS: ; fname = name of the raw data file that need to be treated ;OUTPUT: ; result = name of the FITS file created from fname ;- ;+ ; NAME: ; AUTOMATE_S055 ;PURPOSE: ; Transforms all the S055 raw data files it found into FITS files ;EXPLANATION: ; Creates a list of all the image.tTT.fFFF (compressed or not) ; Either transforms them into FITS files, overwriting the existing files, ; or only creates the FITS files that do not fit its list. ; Can create an index of every FITS file in the current directory ; If the index was asked, it can rename the temporary FITS with a more suitable name ;CALLING SEQUENCE: ; AUTOMATE_S055 ;INPUTS: ; none ;OUTPUT: ; none ;- ;+ ; NAME: ; QUICKV ;PURPOSE: ; Quickview of the Raster/Linescan mode S055 FITS files ;EXPLANATION: ; Navigation is done with the mouse. Just click and look! ; The left button displays the following image ; The right button displays the previous image ; The middle button is used for options: change of contrast, ; readout of intensity or exit ;CALLING SEQUENCE: ; QUICKV ;INPUTS: ; none ; But the program asks a "ls type command" to be typed. ; This will help making a selection of the files to be displayed. ;OUTPUT: ; none ;- ;+ ; NAME: ; MODIFY_S055 ;PURPOSE: ; Adds or modify the value of one parameter of the header of a S055 ; FITS file ;EXPLANATION: ; Reads the header and the engineering data ; Calls sxaddpar to change or add the new value ; Asks for confirmation ; Rebuilds the FITS file ;CALLING SEQUENCE: ; MODIFY_S055, fname, title, value, [comment] ;INPUTS: ; fname = name of the FITS file that need to be treated ; title = name of parameter ; value = value of the parameter to be changed/added ;OPTIONAL INPUT: ; comment = String field. ; If ignored, the comment line in the header will be kept. ; Otherwise, this non-empty string will replace the comment line in the ; header. ;OUTPUT: ; none ;- ----------------------------------------- HISTORY OF MODIFICATIONS August 2001, Mathieu HIRTZIG Creation of the IDL routines and of the CD database