***** File FITSHDRS.TXT A selected sample of FITS headers for the nine IHW Disciplines follows: 1.0. ASTROMETRY Table 1.1. Header Keyword Information ______________________________________ Keyword and Its Content ______________________________________ SIMPLE = T BITPIX = 8 NAXIS = 1 NAXIS1 = 2880 OBJECT = 'P/HALLEY' FILE-NUM= 102008 DATE-OBS= '12/ 8/85' TIME-OBS= 0.88403 DATE-REL= '26/ 9/89' DISCIPLN= 'ASTROMETRY' LONG-OBS= '116/ 8/24' LAT--OBS= '-32/00/30' EQUINOX = 'B1950.0' SYSTEM = '18070000' OBSERVER= 'CANDY,M.P ET AL.' SUBMITTR= 'WIMBERLY,R.N' SPEC-EVT= F DAT-FORM= 'ASCII ' COMMENT ADD. OBS.: SMITH,P/DOE,J COMMENT NOTES: VERY FAINT IMAGE END ______________________________________ SYSTEM (C) is the system code in which the leading digit (1) identifies the Astrometry Network and the following three digits are a unique code for the reporting observatory (see Table VI). The trailing four digits are zeroes for the Astrometry Network. OBSERVER (C) gives the name(s) of the observer(s), last name first followed by the initial(s) of their first (and middle) name(s) (see Tables VI and VII). The observers are separated by a slash (/), whereas ET AL. indicates that additional observers (ADD. OBS.) are listed after the COMMENT keyword. Problems with the observation or data reduction process also are identified after a keyword COMMENTS. SUBMITTR (C) is R.N. Wimberly as the person who prepared the original data archive tape and submitted it to the IHW Lead Center at JPL. The SPEC-EVT (L) keyword is not used in the Astrometry Network. DAT-FORM (C) describes the format of the FITS data record, which for Astrometry is to be interpreted as logical records of 80 ASCII characters. __________________________________________________________________________ 2.0. INFRARED STUDIES Table 2.1. Keywords in the FITS Primary Headers(1) ______________________________________________________________________________ Keyword Description ______________________________________________________________________________ SIMPLE Conformity to FITS format (T = yes, F = no) BITPIX Number of bits/pixel NAXIS Number of axes in array NAXIS1 Data array size, axis 1 NAXIS2 Data array size, axis 2 EXTEND Conformity with (new) extension standard (T = yes, F = no) OBJECT Name of object FILE-NUM File identification number DATE-OBS Date of middle of observation (UT) (dd/mm/yy) TIME-OBS Time of middle of observation (expressed in decimal days UT) DATE-REL Date when observation may be publicly released (dd/mm/yy) DISCIPLN IHW Discipline (IR STUDIES) LONG-OBS East longitude of observatory (0-360 deg) LAT--OBS Latitude of observatory (+ = north, - = south) SYSTEM Observing system code 2NNNXXYY, where 2 denotes the IR Studies Network, NNN the IAU observatory code (= 500 if not in IAU list), XX the telescope number as collated by LSPN (if NNN = 500, XX = country code), and YY not used OBSERVER Observer(s) name(s) SUBMITTR Submitter(s) name(s) SPEC-EVT Special event (T = yes, F = no) DAT-FORM Form of data: 'STANDARD' if data records conform to FITS standard, 'ASCII' for tables, or 'NODATA' if data were not submitted DAT-TYPE Type of data being submitted OBSVTORY Name of submitting observatory LOCATION Location of submitting observatory TELESCOP Telescope identification (size) INSTRUME Instrument used COMMENT Cols. 9-80 are a comment HISTORY Cols. 9-80 are a comment FILTER Type of filter used APERSIZE Entrance aperture size (arcsec) AIRM-AVG Average airmass of observation RANGE-SP Approximate spectral range (microns) RESOL-SP Approximate spectral resolution (microns) DIS-CODE Filter table number (in filter table files) BSCALE Scale factor used to convert tape pixel values to true values (true = tape * BSCALE + BZERO) BZERO Offset applied to tape pixel values to convert to true values BUNIT Data units BLANK Missing pixel filler value CDELTn Pixel spacing along axis n of data array CTYPEn Units along data axis n CRPIXn Pixel number of nucleus along axis n PIXSCALE Pixel size in arcsec DATAMIN Minimum data value in the file DATAMAX Maximum data value in the file END End of FITS header ______________________________________________________________________________ (1) Table extension keywords are defined and formatted in each file. 3.0. LARGE-SCALE PHENOMENA NETWORK Table 3.1. Sample FITS header for Large-Scale Phenomena ______________________________________________________________________________ Keyword Content Explanation ______________________________________________________________________________ SIMPLE = T / BASIC FITS FORMAT BITPIX = 16 / 2-BYTE TWO'S COMPL INTEGERS NAXIS = 2 / NUMBER OF AXES, 2=SINGLE IMAGE, 3=MULTIPLE NAXIS1 = 4096 / PIXELS PER ROW NAXIS2 = 3072 / LINES PER IMAGE OBJECT = 'P/HALLEY ' / NAME OF OBJECT FILE-NUM= 300691 / NUMBER OF FILE SENT TO JPL, DNNNNN DATE-OBS= '20/03/86 ' / DATE OF MID-EXPOSURE DD/MM/YY TIME-OBS= 0.29028 / TIME OF MID-OBSERVATION, DAY FRACTION DATE-REL= '07/31/90 ' / DATA RELEASE DATE, DD/MM/YY DISCIPLN= 'LARGE SCALE PHEN ' / IHW NETWORK LONG-OBS= '289/11/07 ' / STATION LONGITUDE DDD/MM/SS LAT--OBS= '-30/09/55 ' / STATION LATITUDE SDD/MM/SS SYSTEM = '38070400 ' / OBSERVING SYSTEM CODE OBSERVER= 'MILLER,F ' / NAME OF OBSERVER WHO TOOK PLATE SUBMITTR= 'NIEDNER,M ' / LSPN SUBMITTER SPEC-EVT= T / SPECIAL EVENTS FLAG DAT-FORM= 'STANDARD ' / STANDARD FITS DATA DAT-TYPE= 'IMAGE ' / TYPE OF FITS DATA LSPNSEQ = 110331 / SEQUENCE # OF PLATE RECEIVED AT LSPN OBSVTORY= 'UNIVERSITY OF MICHIGAN/CTIO ' / NAME OF OBSERVATORY LOCATION= 'LA SERENA, CHILE ' / STATION LOCATION - ADDRESS TELESCOP= 'CURTIS SCHMIDT ' / TYPE OF TELESCOPE APERTURE= 0.610 / APERTURE, METERS FRATIO = 3.500 / EFFECTIVE TELESCOPE F RATIO FOV1 = 5.000 / RA FIELD OF VIEW, DEGREES FOV2 = 5.000 / DEC FIELD OF VIEW, DEGREES PLTSZE1 = 0.203 / X PLATE SIZE, METERS PLTSZE2 = 0.203 / Y PLATE SIZE, METERS PLTSCALE= 96.661 / PLATE SCALE ARC SECONDS PER MM CALAVL = T / CALIBRATION AVAILABLE HYPSEN = T / HYPERSENSITIZATION EMULSION= 'IIA-O ' / EMULSION TYPE FILTER = 'NONE ' / TYPE OF FILTER USED PLTYPE = T / PLATE TYPE, T=ORIGINAL, F=COPY EXPOSURE= 1200. / EXPOSURE TIME, SECONDS HISTORY OBSLOG = '29953 ' / ORIGINAL OBSERVATORY PLATE BSCALE = 1.0 / SCALE FACTOR, TRUE = TAPE * BSCALE + BZERO BZERO = 0.0 / OFFSET FOR TRUE PIXEL VALUE BUNIT = 'DENSITY ' / UNITS OF PIXEL VALUES HISTORY SCNAPR = 40 / PDS SCAN APERTURE, MICRONS HISTORY SCNSTP = 40 / PDS SCAN STEP, MICRONS HISTORY SKYDEN = 190 / SKY BKGND PDS DENSITY HISTORY SKYUNF = 'EXCL ' / SKY BKGND POOR/FAIR/GOOD/EXCL CTYPE1 = 'RA---ARC ' / X AXIS UNITS CTYPE2 = 'DEC--ARC ' / Y AXIS UNITS EQUINOX = 1950.0 / EQINOX OF COORDINATE SYSTEM RA--CPME= 0.293700E+03 / RA PLATE CENTER MID-EXPOSURE DEC-CPME= -0.264086E+02 / DEC PLATE CENTER MID-EXPOSURE CRPIX1 = 0.162615E+04 / REF POINT FOR AXIS1, SAMPLES CRPIX2 = 0.148793E+04 / REF POINT FOR AXIS2, LINES CDELT1 = -0.107401E-02 / RA PER PIXEL, DEGREES CDELT2 = -0.107401E-02 / DEC PER PIXEL, DEGREES CROTA1 = 0.121025E+00 / ROTATION ANGLE IN RA, DEGREES CROTA2 = 0.121025E+00 / ROTATION ANGLE IN DEC, DEGREES SENSE = T / SENSE OF ROTATION, T=CCW, F=CW CRVAL1 = 0.293700E+03 / RA AT REFERENCE POINT, DEGREES CRVAL2 = -0.264086E+02 / DEC AT REFERENCE POINT, DEGREES RA--HEAD= 0.295308E+03 / RA COMET HEAD MID-EXPOSURE DEC-HEAD= -0.261628E+02 / DEC COMET HEAD MID-EXPOSURE DATE-REC= '04/06/87 ' / DATE PLATE WAS RECEIVED AT GSFC, DD/MM/YY HISTORY DATE-PDS= '20/03/87' / DATE DIGITIZED DD/MM/YY HISTORY DATE-PRC= '13/07/88' / DATE PROCESSED/CALIBRATED DD/MM/YY QUALITY = '123 ' / QUAL OF PLATE,GUIDING,TRAILS,SEEING,TRANSP END ______________________________________________________________________________ SYSTEM is a code denoting the observatory and the instrument used to obtain the image, and the location of the observing site. The archive user is referred to the LSPNOBS.TXT file in the DOCUMENT directory of the set of L-SP compressed image discs, HAL_0001 through HAL_0018. Detailed information associated with each SYSTEM code can be found there, information which is also contained in the delimited index LSPNOBS.IDX in the INDEX directory on those same discs. A file listing observatory information across all IHW disciplines is OBSCODES.TXT, which has been deposited in the DOCUMENT directory of these "mixed discs" (HAL_0019--HAL_0023). SPEC-EVT is a keyword signifying the presence or absence of a "special event", and is either "T" or "F" in value. In nearly all cases it was the L-SP Discipline Specialist (M. Niedner) who evaluated the imagery and set this parameter. Disconnection events (DEs) in the plasma tail, strong bursts of tail ray generation, and large amplitude bends in the tail, are but a few of the situations meriting a SPEC-EVT = T. The classification is obviously somewhat subjective and the DS should not be held responsible for database searches of NETLARGE.IDX (resident in the INDEX directory of the compressed image discs) keyed solely to SPEC-EVT; it is a coarse parameter that is meant only to signify possible interest in an image. PLTSCALE should be used with caution. It does indicate plate scale, but only for original plates or films. Moreover, it is derived from the focal length of the telescope, not astrometrically, and hence never varies from one original image to the next taken on the same telescope. In some cases, most notably 35mm film negatives on Kodak Technical Pan 2415, the digital scan was made of a greatly enlarged film copy of the original small frame. In this case PLTSCALE is not remotely close to the scale of the digital image. We have provided a rigorous astrometric plate solution for each scanned image, and the true "digital image scale" is contained in other FITS keywords (CDELT1,2 and SCNSTP, described below). CALAVL is a keyword signifying the existence or absence of calibration data associated with the Halley image. A value of "T" does not, however, necessarily mean that the calibration information resides on these CD-ROMs, because not all calibration plates were digitized by the L-SP Team. Refer to the text file CALIB_LS.TXT in the DOCUMENT directory of these "mixed discs" (or to the CALIB.TXT file on the compressed image discs) for a discussion of which calibration data were included in the archive. The filenames of calibration datafiles in the archive are contained in text tables in CALIB_LS.TXT and in delimited index table CALIB_LS.IDX of directory INDEX. PLTYPE designates whether the digitized image was an original plate or film ("T") or a copy ("F") made by either the contributing observer or by the L-SP Team. In the latter category it should be mentioned that in some cases the observer sent the DS a film copy of sufficient quality for scanning, and in other situations it was necessary to enlarge original small images prior to digitization. CRPIX1,2....CRVAL1,2 form a block of "astrometric keywords", the names and meanings of most of which are identical to keywords defined by Wells et al. (1981). Briefly, CRPIX1 and CRPIX2 fix the location of the upper-left (NE) corner of the scan area relative to the reference position, in numbers of samples and lines, respectively. We have adopted the plate center as the reference position, or "reference pixel" as it is called. CDELT1 and CDELT2 are self-explanatory, but it should be noted that the "classical" plate scale in arcsec/mm can be derived from CDELT1(,2) and SCNSTP (scan step in microns) if one wishes it. CROTA1 and CROTA2 were not tightly defined in the original FITS paper (Wells, D.C., et al.,1981), so we wish to be specific here about how the angles are measured. First, we define CROTA1=CROTA2, always. The angle(s) refer to the rotation of the X-Y PDS (microdensitometer) coordinate frame relative to the axes of the celestial coordinate system. The Large-Scale Phenomena Appendix, LS_PHEN.APX (resident in the DOCUMENT\APPENDIX directory), contains a pictorial diagram to which the Archive user may wish to refer. To reasonable accuracy, the +Y scanning axis is in the direction of North at the plate center, for the epoch of 1950.0. The +X scanning axis is in the approximate direction of due East (again, at the plate center for 1950.0). As a result of the inevitable human error in positioning the plate on the PDS platen, however, there will be a non-zero rotation angle offset (very small) between the two coordinate systems. When the North direction lies in the +X/+Y quadrant, i.e., is rotated in a counterclockwise direction relative to the +Y axis, we say that the rotation angles CROTA1 and CROTA2 are both positive (and the same value). A positive angle for such a counterclockwise rotation is what is meant by SENSE = T, and we adopt SENSE = T throughout this archive. Because of its redundancy, the keyword SENSE is not indexed in NETLARGE.IDX, although it is present in the individual FITS headers. CRVAL1 and CRVAL2 are the right ascension and declination of the reference position, which we have made the plate center. Note that these coordinates are separately given as RA--CPME and DEC-CPME, the formal coordinates of the plate center. RA--HEAD and DEC-HEAD are the measured (approximate) coordinates of the head center, but are not given in either the FITS headers or the appropriate lines in the index table for those plates which did not contain the head region. Note that the head center coordinates are for reference purposes only and are not to be used for accurate positions of the nucleus; well-saturated, wide-field plates are obviously not suitable for that purpose. QUALITY is a keyword which gives a very subjective assessment of the condition of each scanned image in terms of five categories (plate, guiding, trails, seeing, and transparency); the scale is 1-5 (excellent to poor). Not for all plates was it possible to evaluate each category, and hence the archive user will occasionally come across (for example) QUALITY = '123 '. 4.0. NEAR NUCLEUS Table 4.1. The NNSN Header Keywords ______________________________________________________________________________ SIMPLE = T /T conforms to standard FITS format BITPIX = 16 /16 (or 32)-bit data NAXIS = 2 /number of axes in array NAXIS1 = ____ /number of pixels in X axis (samples) NAXIS2 = ____ /number of pixels in Y axis (rows) OBJECT = 'P/HALLEY' /object name FILE-NUM= 4_____ /file number DATE-OBS= '__/__/__' /mid-UT date of observation (dy/mo/yr) TIME-OBS= ._____ /mid-UT decimal part of day DATE-REL= '__/__/__' /date released to archive (dy/mo/yr) DISCIPLN= 'NEAR NUCLEUS' /IHW network LONG-OBS= '___/__/__' /observatory east longitude (deg/min/sec) LAT--OBS= '___/__/__' /observatory latitude (+-deg/min/sec) SYSTEM = '4_______' /observing system code OBSERVER= '__________________' /observer's names (see ADD. OBS.:in COMMENT) SUBMITTR= '__________________' /submitter's names SPEC-EVT= _ /T if jets present (10/85-6/86) DAT-FORM= 'STANDARD' /type of data OBSVTORY= '__________________' /observatory name ELEV-OBS= ____ /elevation of observatory in meters TELESCOP= '__________________' /telescope used APERTURE= _.__ /telescope aperture in meters TELEFL = _.___ /effective focal length in meters PLTSCALE= __.__ /plate scale in arcsec per mm CROTA1 = ___._ /position angle of sample axis, north -> east SENSE = _ /PA counterclockwise (T) or clockwise (F) DETECTOR= '__________________' /detector used DIGITIZE= '__________________' /type of digitizer used if not detector APSIZE = _.___ /original pixel size of detector/digitizer FILTER = '______ ' /filter used (see Table IV) EXPOSURE= ____._ /exposure duration in seconds AIRM-MID= _.___ /calculated airmass at mid-exposure QUALITY = '_________' /general quality of image DATE-WRT= '__/__/__' /date this file written ORIGIN = '__________________' /institution sending data to NNSN BUNIT = '__________________' /intensity units (note that BSCALE=1, BZERO=0) COMETMAX= ______ /approximate maximum value in comet image SKYMIN = ______ /approximate background sky brightness COMMENT (any comments relating to the image contents and additional observers) HISTORY (any comments relating to the reduction process) END _____________________________________________________________________________ The 250 system codes are specific to any detector, array size, telescope, optical configuration and filter, and are of the form 4NNNXXYY, where 4 denotes the NNSN, NNN is the IAU observatory code, XX the telescope, and XX the filter/scale/array size configuration. A list of observers are associated with each system code, so more than one observer group may share a system code. The quality rating is only a rough, qualitative guide that includes the effects of seeing, focussing, guiding, the signal-to-noise ratio, and decalibration. The four rating categories are excellent, good, fair, and poor: excellent refers to images with no obvious flaws and poor denotes images included only because of the lack of better ones on that day. The user will have to gain some experience to know what to expect from the different grades. The airmass at mid-exposure (AIRM-MID) is calculated from current epoch topocentric comet coordinates (RA, DEC) and observatory coordinates (LONG, LAT) as: AIRM-MID = sec Z - 0.0018167 (sec Z - 1) - 0.002875 (sec Z - 1)**2 - 0.0008083 (sec Z - 1)**3, where the zenith distance Z follows from: sec Z = 1/[sin(LAT)*sin(DEC) + cos(LAT)*cos(DEC)*cos(local hour angle)]. The airmass at the zenith is 1, so it does not include a correction for the local elevation. Also note that there is no correction for apparent and true zenith distance. 5.0. PHOTOMETRY AND POLARIMETRY Table 5.1. FITS Header Keywords ______________________________________________________________________________ Item FITS Keyword Format Value/Explanation ______________________________________________________________________________ Comet Name OBJECT string 'P/HALLEY' for all files in this archive. File Number FILE-NUM I6 '56xxxx' 5 ==> Photometry/Polarimetry Network 6 ==> P/Halley xxxx = running number, not in chronological order Date DATE-OBS dd/mm/yy Date of the observations UT Time TIME-OBS F6.5 Decimal fraction of the day at the midpoint of the observations in the table UT Start Time TIME-STR F6.5 Decimal fraction of the day at the start of the observations in the table when available. Our Network DISCIPLN string 'PHOTOMETRY' for this Network Observatory OBSVTORY string Name of observatory Longitude LONG-OBS ddd/mm/ss Positive, eastward from Greenwich Latitude LAT--OBS sdd/mm/ss s='+' or '-' for North or South Elevation ELEV-OBS I4 [m] System SYSTEM I8 See Sec. 7 Telescope TELESCOP string A unique identification of the telescope by name or size Type of data DAT-TYPE string 'POLARIMETRY', 'STOKES", 'BROADBAND' or 'NARROWBAND'. Note the tables that follow 'Fluxes' refers to 'NARROWBAND' and 'Magnitudes' refers to 'BROADBAND' Observer(s) OBSERVER string Name(s) of observer(s) (omitted for FES observations with IUE;large team headed by Feldman & Festou) Submitter SUBMITTR string Person who submitted data to the DS. A blank usually means data were taken from the literature. Comments COMMENT string All comments are character strings (line = 80 characters) following the keywords 'COMMENT' and 'HISTORY' and in some cases the following secondary keywords: 'LIT.' => reference from literature 'NOTE' => footnote to table 'NOTExx' => footnote to line xx 'ADD. OBS.' => names of additional observers beyond those above HISTORY string Comments relevant to calibration 'STDSTARS' => list of standard sta s used in the reduction. In case of polarimetry standard stars POL-STD refers to highly polarized stars, and UNPOL-STD to unpolarized stars ______________________________________________________________________________ The FITS tables can take any of four different formats depending on the type of data in the table. The types of table are known by the following values for the FITS 'DAT-TYPE' keyword: 'BROADBAND', 'NARROWBAND', 'POLARIMETRY', and 'STOKES'. Note that the value 'BROADBAND' is actually used to indicate results given in magnitudes rather than fluxes. It is independent of the actual bandwidth of the filters used. The first few columns in the tables are identical for all types of data and are listed in Table 5.2. Additional entries for DAT-TYPE = 'BROADBAND' are in Table 5.3, for DAT-TYPE = 'NARROWBAND' in Table 5.4, for DAT-TYPE = 'POLARIMETRY' in Table 5.5, and for DAT-TYPE= 'STOKES' in Table 5.6. Table 5.2. Columns Common to All Types of Data ______________________________________________________________________________ Item Format Columns Explanation ______________________________________________________________________________ Date and time(UT) F8.5 1 - 8 Day of month and decimal frac- tion at mid-point of observa- tion Serial number I2 10 - 11 Line number in the table Occasional numbers are skipped Filter name A4 13 - 16 Short-hand name wavelength I4 18 - 21 Central wavelength [A] width I4 23 - 26 FWHM [A] ______________________________________________________________________________ Table 5.3. Columns for Magnitudes (DAT-TYPE = 'BROADBAND') ______________________________________________________________________________ Item Format Columns Explanation ______________________________________________________________________________ Upper limit code char 28 '<' indicates that the result in the following field is a 3-sigma limit Magnitude F7.3 30 - 36 Reduced magnitude error F5.3 38 - 42 One (1) sigma [mag]; omitted if previous field is a limit Aperture size F5.1 44 - 48 Diameter [arcsec] Radial offset I4 50 - 53 Radial distance between center of aperture and the peak brightness of the comet [arcsec] Offset direction I3 55 - 57 Angular direction [deg] (eastward from north) of the radius vector to the center of the aperture from the peak in brightness Integration time I4 59 - 62 Integration time [s] Airmass F5.3 64 - 68 Airmass at midpoint in time, usually as quoted by observer ______________________________________________________________________________ Table 5.4. Columns for Fluxes in Narrowband Filters (DAT-TYPE = 'NARROWBAND') ______________________________________________________________________________ Item Format Columns Explanation ______________________________________________________________________________ Upper limit code char 28 '<' indicates that the result in the following field is a 3-sigma limit Log Flux F7.3 30 - 36 Logarithm (base 10) of the flux See Sec. 4 for details error F5.3 38 - 42 Error of log10 of flux Aperture size F5.1 44 - 48 Diameter [arcsec] Radial offset I4 50 - 53 Radial distance between center of aperture and the peak brightness of the comet [arcsec] Offset direction I3 55 - 57 Angular direction [deg] (eastward from north) of the radius vector to the center of the aperture from the peak in brightness Integration time I4 59 - 62 Integration time [s] Airmass F5.3 64 - 68 Airmass at midpoint in time ______________________________________________________________________________ Table 5.5. Columns for Polarimetry in Percent (DAT-TYPE = 'POLARIMETRY') ______________________________________________________________________________ Item Format Columns Explanation ______________________________________________________________________________ Polarization type A2 28 - 29 'CR' => right circular 'CL' => left circular 'LN' => linear Polarization value F5.2 31 - 35 Degree of polarization [%] error F5.2 37 - 41 One (1) sigma [%] Position angle F5.1 43 - 47 For linear polarization, the position angle of the electric vector [deg] clockwise from the plane of scattering (-45 to +135) error F4.1 49 - 52 One sigma Aperture size F5.1 54 - 58 Diameter [arcsec] Radial offset I4 60 - 63 Radial distance between center of aperture and the peak brightness of the comet [arcsec] Offset direction I3 65 - 67 Angular direction [deg] (eastward from north) of the radius vector to the center of the aperture from the peak in brightness Integration time I4 69 - 72 Integration time [s] Airmass F5.3 74 - 78 Airmass at midpoint in time, usually as quoted by observer ______________________________________________________________________________ Table 5.6. Columns for Stokes Vectors (DAT-TYPE = 'STOKES') ______________________________________________________________________________ Item Format Columns Explanation ______________________________________________________________________________ Q/I F7.4 28 - 34 Normalized Stokes parameter Q/I, positive for the electric vec- tor perpendicular to the plane of scattering, negative for the electric vector parallel to the plane [dimensionless] error F6.4 36 - 41 One sigma U/I F7.4 43 - 49 Normalized Stokes parameter U/I, positive for the electric vec- tor 45 deg counterclockwise from positive values of Q, negative for 45 deg clockwise [dimensionless] error F6.4 51 - 56 One sigma V/I F7.4 58 - 64 Normalized Stokes parameter V/I, positive for left handed as seen by the observer, negative for right handed as seen by the observer [dimensionless] error F6.4 66 - 71 One sigma Aperture size F5.1 73 - 77 Diameter [arcsec] Radial offset I4 79 - 82 Radial distance between center of aperture and the peak brightness of the comet [arcsec] Offset direction I3 84 - 86 Angular direction [deg] (eastward from north) of the radius vector to the center of the aperture from the peak in brightness Integration time I4 88 - 91 Integration time [s] Airmass F5.3 93 - 97 Airmass at midpoint in time, usually as quoted by observer 6.0. RADIO SCIENCE Table 6.1. Keyword Block I ______________________________________________________________________________ Keyword Type Description ______________________________________________________________________________ SIMPLE L Conformity to basic FITS standards BITPIX I Bits per pixel in data record NAXIS I Number of axes in data record; if NAXIS = 0 then no data record NAXIS1 I Number of pixels in row along first axis; if NAXIS1 = 0 then this is Extended FITS Format and GROUP data are present NAXISn I Number of pixels along n-th axis in image OBJECT C Name of the object Examples: 'P/CROMMELIN' 'P/HALLEY' 'P/GIACOBINI-ZINNER' FILE-NUM I 6NNNNV - unique, sequential number to identify files sent to IHW Lead Center. Format description: 6 = denotes Radio Science Network NNNN = unique 4 digit ID number assigned to each observation V = version number (used to keep track of resubmissions) DATE-OBS C 'DD/MM/YY' - UT date of middle of observation if observations made during several intervals, then these intervals will be specified in the HISTORY fields described below TIME-OBS R UT time of middle of observation expressed in decimal days DATE-REL C 'DD/MM/YY' - date when observations may be publicly released DISCIPLN C 'RADIO STUDIES' - the Network identification LONG-OBS C 'DDD/MM/SS' - east longitude of observatory (0-360 deg) LAT--OBS C 'sDD/MM/SS' - latitude of observatory SYSTEM C '6OOOCCTT' - system code formatted: 6 = Radio Science Network OOO = IAU number for observatory (OOO = 500 for radio observatories since no IAU number exists) CC = identifies country according to LSPN Code TT = identifies radio telescope OBSERVER C Name of observer Format : 'LASTNAME,I' - 1 author 'LASTNAME,I/NEXTNAME,J' - 2 authors 'LASTNAME,I/ET AL.' - >2 authors For more than 2 observers, the names of all additional observers are given in special ADD. OBS. comments SUBMITTR C Name of submitter of data SPEC-EVT L Flag for special events as designated by Discipline Specialist DAT-FORM C Describes format of FITS data records 'NODATA ' - no FITS data records written 'STANDARD' - data records conform to FITS standard 'ASCII ' - data records are to be interpreted as logical records of 80 ASCII characters (not FITS standard) 'HARDCOPY' - data submitted as hardcopy ______________________________________________________________________________ Table 6.2. Keyword Block III ______________________________________________________________________________ Keyword Type Description ______________________________________________________________________________ DIS-CODE C 'TFESEWEABENC' - describes parameters of the telescope/ instrument T : Telescope type S = single antenna I = interferometer U = unknown/unclassified FE: Frequency (Center Frequency or Rest Frequency) FE=> frequency = F x 10**(E) MHz 00= unknown SE: Spectral resolution SE=> spectral resolution = S x 10**(E) Hz 00= unknown WE: Bandwidth WE=> bandwidth = W x 10**(E) Hz 00= unknown A : Beam description C = circular E = ellipitical O = other U = unknown BE: Beam size (geometric mean) BE=> beam size = B x 10**(E) arcsec 00= unknown N : Noise estimate N => RMS noise = 10**(N) microJansky/beam 0 = unknown C : Information provided by observer to Discipline Specialist is complete T = TRUE F = FALSE DAT-TYPE C 'NNSTHP' - describes the data format in Header and Data Records NN: Subnetwork OH= OH Subnetwork Spectral line observations of 18-cm OH SL= Spectral Line Subnetwork Spectral line observations (other than 18-cm OH) CN= Continuum Subnetwork Broadband continuum observations OC= Occultation Subnetwork Observation of occultation events RD= Radar Subnetwork Active experiments S : Search/detection status S = search - implies nondetection (< 3 sigma) D = detection - implies detection (> 3 sigma) M = marginal - implies marginal detection (approx. 3 sigma) T : Type of data in FITS Data Records N = no FITS Data Records S = Spectrum => intensity vs frequency C = Continuum scan => intensity vs space T = Time series => intensity vs time I = Image => spatial - spatial image D = Dynamic spectrum => frequency - time image F = SV image => frequency - spatial image V = Visibility Function Data H : Summary of Data in Header? T = Summary of data exists in Header History Section F = No summary of data in Header History Section P : Polarization status I = Intensity data only P = Polarization data format used OBSVTORY C Abbreviation for Observatory. TELESCOP C Telescope identifier - usually gives aperture size in meters LOCATION C Location of Observatory as given in American Ephemeris INSTRUME C 'FRONT/BACK' - describes "frontend" and "backend" of receiver FRONT: Receiver Front End MASER = Maser Amplifier FET = Field Effect Transistor Amplifier PARA = Parametric Amplifier MIXER = Mixer SPEC = Special Front End UNK = Unknown Front End BACK : Receiver Back End FB = Filterbank SEFB = Filterbank with Spectrum Expander AC = Autocorrelator CONT = Broadband Continuum Receiver SPEC = Special Back End AOS = Acousto-Optical Spectrometer UNK = Unknown Back End CENTFREQ R Center frequency of observed bandwidth (Hz) BANDWIDT R Total bandwidth (Hz) BEAMSIZE R Geometric mean of major and minor axes of Elliptical Gaussian Beam (deg) BEAMELON R Ratio of major beam axis to minor beam axis BEAMROTA R Position angle of major beam axis (deg) BEAMEFF R Beam efficiency - fraction of power received that is in the Gaussian Main Beam (BEAMEFF = 0.0 if unknown or unspecified) MOLECULE C Chemical formula for molecule (follows convention of NBS interstellar-line list) TRANSITN C Quantum numbers for transition (follows convention of NBS interstellar-line list) RESTFREQ R Rest frequency of line used by observer (Hz) RES-SPEC R Spectral resolution (Hz) - true spectral resolution of the spectrometer, NOT the channel spacing EQUINOX R Equinox of RA-DEC information presented in this file RAOFF R Pointing offset in RA direction DELTA(RA)*COS(DEC) (deg) DECOFF R Pointing Offset in Dec direction DELTA(DEC) (deg) DATE-BEG C 'DD/MM/YY' - UT date on which observations began DATE-END C 'DD/MM/YY' - UT date on which observations ended ______________________________________________________________________________ There is a group of COMMENT lines give additional information to be used in the production of the IHW printed archive. The ADD. OBS. comment gives the names of the full observing team in the case that more than two observers carried out the observations. More than one ADD. OBS. comment may be used to specify teams with many members or long names. The format of the ADD. OBS. comment is: COMMENT ADD. OBS. NAME,I/NAME2,I/NAME3,I The NOTE comment provides information that is to be printed as a footnote in the printed archive in the following format: COMMENT NOTE THIS IS A TEST Next there are FITS HISTORY keywords provided to incorporate additional information about the observation, such as descriptions of calibration methods and sources, details about observing procedures, and comments by the observer and the IHW Discipline Specialist. Another important use of the HISTORY lines is to provide a summary of the data obtained, or in the case of FITS files with no data records, the actual data values reported by the observer. The general format of the HISTORY lines is: column 1 11 21 HISTORY SUBKEY__ VALUES.... where values is a list of values associated with this subkey. In most cases, the value lists are in a fixed format in order to simplify their use. In order to transmit upper limits or a summary of the data that would be appropriate for tabular presentation in the printed archive, we utilize one of the following HISTORY keyword formats. Such summaries of the data will always be contained in the first part of the HISTORY keyword section; the presence of such a summary shall be indicated in the DAT-TYPE keyword discussed above. In the case where FITS data records accompany the header, USERS OF THE ARCHIVE ARE CAUTIONED THAT THE SUMMARY VALUES ARE ONLY MEANT TO DESCRIBE AND CHARACTERIZE THE DATA ... NOT TO REPLACE THEM. All summary lines follow the same general form: HISTORY SUBKEY ################ 'UNITS ' where the # field is a right justified floating point number. Format for Upper Limits: COMMENT *SUMMARY OF DATA - UPPER LIMIT HISTORY LIMIT 0.5 'JY/BEAM ' Upper limits in the Radio Science Network are always given as 3 standard deviation upper limits. Format for Spectral Lines: COMMENT *SUMMARY OF DATA - SPECTRAL LINE HISTORY LINEPEAK 0.5 'JY/BEAM ' HISTORY ERR-PEAK 0.1 'JY/BEAM ' HISTORY LINE-VEL 10.0 'M/SEC ' HISTORY ERR--VEL 200.2 'M/SEC ' HISTORY LINE-WID 2532.0 'M/SEC ' HISTORY ERR--WID 130.2 'M/SEC ' HISTORY LINEAREA 1243.1 'JY/B*M/S' HISTORY ERR-AREA 143.6 'JY/B*M/S' HISTORY LINEMEAN 32.1 'M/SEC ' HISTORY ERR-MEAN 10.2 'M/SEC ' The spectral line summary values LINEPEAK, LINE-VEL, and LINE-WID are determined from gaussian fits to the line profiles. If one or more parameters were fixed in a fit to the data, the assumed values are listed with no errors. Spectral lines with hyperfine structure (e.g., HCN) are fitted on the assumption that all hyperfine components have their nominal intensity ratios. Format for Continuum Observations: COMMENT *SUMMARY OF DATA - CONTINUUM HISTORY CONTFLUX 0.5 'JY/BEAM ' HISTORY ERR-FLUX 0.1 'JY/BEAM ' Format for Radar Observations: COMMENT *SUMMARY OF DATA - RADAR HISTORY XSECTION 30.0 'SQUARE KILOMETERS' HISTORY ERR-XSEC 6.0 'SQUARE KILOMETERS' Since many radio observations take place over several days, we include the precise observing windows in the HISTORY section according to the format: COMMENT *OBSERVING WINDOW SPECIFICATION HISTORY N-WINDOW # HISTORY WINDOW 'DD/MM/YY' ####### 'DD/MM/YY' ####### HISTORY WINDOW 'DD/MM/YY' ####### 'DD/MM/YY' ####### where N-WINDOW gives the total number of windows for observation and subsequent window lines give the date and time (in decimals as in TIME-OBS) of beginning and end of the observing window. The time fields are right justified floating point numbers. Radio observers track the comet "blind" and it is important to know the precise position on the sky that they were tracking. We include a provision in the HISTORY section to specify the two-body elements and observatory position data used to produce the topocentric ephemeris for tracking. COMMENT *ORBITAL ELEMENT SPECIFICATION HISTORY ORBELEM T - T if orbital elements are provided HISTORY LONGEAST 243.11046715 - east longitude of observatory (deg) HISTORY RHO--COS 0.8159113419 - radius*cos(lat) for observatory (units of Earth equatorial radius) HISTORY RHO--SIN 0.5765085118 - radius*sin(lat) for observatory (units of Earth equatorial radius) HISTORY ET-UT 53.18439 - Ephemeris Time - UT correction (s) HISTORY JD 2446471.16128 - Time of Perihelion passage (ET) HISTORY Q 0.5870959 - Perihelion Distance (AU) HISTORY E 0.9672671 - Eccentricity HISTORY SOMEGA 111.85336 - Arg. of Perihelion (deg) HISTORY LOMEGA 58.15313 - Long. of Ascending Node (deg) HISTORY I 162.23779 - Inclination (deg) Another HISTORY keyword specifies the antenna rms pointing errors. COMMENT *RMS POINTING ERROR OF TELESCOPE HISTORY POINTERR ################ 'UNITS ' There is a group of keywords to provide information on the calibration process. COMMENT *CALIBRATION METHOD INFORMATION HISTORY CALMETH 'DESCRIPTION OF CAL METHOD' If the calibration method is unknown, then no line appears. Current possible values are 'CHOPPER WHEEL', 'NOISE TUBE', 'STANDARDS', 'ABSOLUTE'. COMMENT *CALIBRATION STANDARD INFORMATION HISTORY CALSRCE 'SOURCE NAME' ########## 'UNITS ' Source (or sources) used to provide principal calibration. The # field is a right justified floating point number. For planets as the calibrators, the assumed brightness temperature is given; otherwise, the calibrator flux density is given in Jansky. There may be more than one CALSRCE HISTORY line. COMMENT *SYSTEM TEMPERATURE ETC. HISTORY TSYSTEM ############### '_SB ' HISTORY TRCVR ############### '_SB ' Total system temperature (TSYSTEM) and noise temperature of the reciver alone (TRCVR). '_SB ' allows single side band measurement ('SSB ') or double sideband measurement ('DSB ') to be indicated. The # field is a right justified floating point number. HISTORY TAUZENTH ############### Atmospheric opacity at zenith. The # field is a right justified floating point number. A block of HISTORY lines contains any extra comments about conditions, data quality, etc. that are sent to the Discipline Specialist by the observer. There are generally fewer than eight such comment lines given. COMMENT *OBSERVER COMMENTS HISTORY OBSCOMM ROOM TO REPORT OBSERVER COMMENTS HISTORY OBSCOMM ... HISTORY OBSCOMM ... HISTORY OBSCOMM MORE ROOM FOR OBSERVER COMMENTS Comments by the Discipline Specialist team on this observation. There are generally fewer than eight such comment lines given. COMMENT *DISCIPLINE SPECIALIST COMMENTS HISTORY DSCOMM ROOM TO REPORT DISCIPLINE SPECIALIST COMMENTS HISTORY DSCOMM ... HISTORY DSCOMM ... HISTORY DSCOMM MORE ROOM FOR DISCIPLINE SPECIALIST COMMENTS Table 6.3. Keyword Block VI ______________________________________________________________________________ Keyword Type Description ______________________________________________________________________________ BSCALE R Scale factor data = tape * BSCALE + BZERO BZERO R Zero value BUNIT C Units of data 'JY/BEAM ' - for line and continuum data 'STANDARD DEVIATIONS' - for radar data BLANK I Value for out-of-range data CRVALn R Value of physical coordinate of nth axis at the reference pixel CRPIXn R Array location of reference pixel for nth axis CDELTn R Increment in physical coordinate along nth axis CTYPEn C Type of physical coordinate 'VELO-COM' - frequency coordinate for line work in m/s defined to be velocity relative to the comet 'VELO-GEO' - velocity defined relative to center of Earth 'FREQUENCY' - frequency offset of radar echo from expected value in units of Hz 'CIRCULAR POLARIZATION' - axis used to define different states of circular polarization: -1 = LHC; -2 = RHC 'LINEAR POLARIZATION' - axis used to define linear polarization position angle 'ECHO POLARIZATION' - axis used to define polarization of radar echo 'RAOFF ' - spatial coordinate for maps (deg) 'DECOFF ' - spatial coordinate for maps (deg) 'RA ' - coordinate used for drift scans (deg) 'MAP-TYPE' - coordinate to indicate type of drift scan map: 0 = map with comet in beam; 1,2 = maps of galactic background only CROTAn R Rotation angle of physical coordinate axis n ______________________________________________________________________________ 7.0. SPECTROSCOPY AND SPECTROPHOTOMETRY Table 7.0. Keywords in the FITS headers ______________________________________________________________________________ Keyword Type Description ______________________________________________________________________________ SIMPLE L Does the file conform to the FITS format? If yes, the keyword is set to T. Otherwise the keyword is F. This keyword should be set to true for all SSN files. BITPIX I Keyword contains the number of bits in each pixel. This value is either 16 or 32 for SSN data. NAXIS I Keyword contains the number of axes in the data: 1-dimensional spectra have a value of 1, 2-dimensional spectra a value of 2. NAXISn I n is a number in the range of 1 to NAXIS. Keyword contains the length of axis. NAXIS1 is the dimension of the fastest varying axis in the data. NAXIS2 is the second fastest varying axis etc. EXTEND L Does the file contain extensions conforming to the FITS stan- dards? For all SSN data files, EXTEND = F (no extensions). OBJECT C Keyword contains the name of the object of the data. FILE-NUM I This is a running number of the files sent to the archive. All values have six places and, for the SSN, begin with 7. For P/Giacobini-Zinner, file numbers are in the range of 700100 to 700999. DATE-OBS C Universal Time [UT] date of middle of data acquisition. Date is given in the FITS standard of day, month, year (DD/MM/YY). TIME-OBS F Fractional part of day, indicating the UT time of the middle of data acquisition. The keyword has a value ranging from 0.0 to 0.99999. DATE-REL C Date the submitter or submitters agree to release their data to the public. DISCIPLN C IHW Discipline. For the SSN the value is always SPECTROSCOPY. LONG-OBS C East longitude of observation station. Keyword value range is from 00/00/00 to 359/59/59. LAT--OBS C Latitude of observation station. Degrees north or south are indicated by a preceding '+' or '-', respectively, 0 has no sign. SYSTEM C Station system code. Keyword is a number of the form 7nnnttii where: 7 = Discipline number (SSN) nnn = IAU Observatory Number tt = Telescope Number, as assigned by the IHW Large Scale Phenomena Network (LSPN) ii = Instrument/Detector Number, assigned by the SSN, and corresponds to DD in DIS-CODE keyword OBSERVER C Name of observer. If more than two observers, first observer listed, followed by ET AL. Additional observers are listed in COMMENT ADD.OBS. keyword. SUBMITTR C Name of person or persons who submitted the data to the IHW SS SPEC-EVT L If true, some special event occurred during observation. See COMMENTs and HISTORYs for more information. DAT-FORM C Form of the data. One of: ASCII, STANDARD, HARDCOPY, NODATA. DAT-TYPE C Type of data being submitted. One of: UNKNOWN, REDUCED DIGITAL, RAW DIGITAL, PHOTOGRAPHIC, OBJECTIVE PRISM, INTERFEROMETRIC, SPACE BORNE. DIS-CODE C This keyword contains a 9-digit integer with the digits define as DDCCWWWRQ, where: DD = Detector/Instrument combination. This is a unique number for each combination and has been assigned by the SSN. The value is the same as ii in the SYSTEM code. CC = Configuration (grating, grating tilt, filter, aperture size, order, etc.) for given telescope and detector/instru ment combination. WWW = Wavelength range [Angstrom], included in data. A binary coding scheme is used to specify a unique number for a unique set of wavelength regions. The number is the sum of all defined values for each spectral region in which data are submitted: 1 = <3000 2 = 3000-3499 4 = 3500-3999 8 = 4000-4999 16 = 5000-5999 32 = 6000-6999 64 = 7000-7999 128 = 8000-10000 256 = >10000 Example: for 3700-6400 A, WWW = 4+8+16+32 = 60. R = Resolution. This parameter is based on the spectral resolution (FWHM in Angstrom). 1 = <= 0.05 2 = > 0.05 - 0.2 3 = > 0.2 - 1 4 = > 1 - 5 5 = > 5 - 10 6 = > 10 - 20 7 = > 20 - 50 8 = > 50 - 100 9 = > 100 Q = Quality of the data. We adopted a qualitative judgement for this parameter, and the values are the same as the QUALITY keyword. 0 = Unknown 1 = Excellent 2 = Very Good 3 = Good 4 = Fair 5 = Poor The files CODE.* contain a full listing of the discipline codes used for P/Giacobini-Zinner, as well as the components which define the DIS-CODE values. These files may be read into a database program, and used to translate DIS-CODE values. OBSVTORY C Name of observatory from which data were obtained. ELEV-OBS F Elevation of the observing station [m]. TELESCOP C Telescope used for observation. Where possible, the telescope name as listed in the Astronomical Almanac has been used. INSTRUME C Instrument and detector used to obtain data. RESOL-SP C Approximate spectral resolution of data [Angstrom]. RANGE-SP C Approximate spectral range of data [Angstrom]. EXPOSURE F Exposure or integration time [s]. APERSIZE C Entrance aperture size or slit width and length of instrument or detector [arcsec]. Airmass F One of the following: AIRM-BEG = Airmass at beginning of observation. AIRM-END = Airmass at end of observation. AIRM-MID = Airmass at midpoint of observation. AIRM-AVE = Average of airmass of observation. SEPNUC F Separation between the comet nucleus and center of slit or aperture [arcsec]; see figure below. ORIENT F Position angle of slit or aperture center with respect to the comet's nucleus, measured north through east, ranging from 0 to 360 deg; see figure below. N ORIENT ^ | | | | POSANG | /| Tail \ N |/ | / E <--- \ ^ ( *======= \ | \/ \ \ | / Nucleus \ \| / \^| /------ SEPNUC \|/ Slit Center ------\ \ \---- Slit \ Definition of angles. POSANG F Position angle of the slit measured north through east, ranging from 0 to 360 deg. Two-dimensional spectra only (figure above). See COMMENT and HISTORY sections for observers' variations of this definition. PIXSCALE F Image scale at detector [arcsec per pixel]. Two-dimensional spectra only. QUALITY I A subjective, qualitative estimate of the data. Values used: UNKNOWN, EXCELLENT, VERY GOOD, GOOD, FAIR, and POOR. CTYPEn C n is a number between 1 and NAXIS. Name of the independent variables: LAMBDAA = Wavelength [Angstrom]. VELOCITY = Velocity [km/s]. PIXELS = Pixel number. RHO = Projected distance [arcsec]. OTHER = Described in a comment. BUNIT C Name of dependent variable: FLAMBDA = Flux per wavelength [erg/cm2/s/Angstrom]. FNU = Flux per frequency [erg/cm2/s/Hz]. RAYLAMBDA = Flux per wavelength [Rayleighs/Angstrom]. RELINS = Relative intensity. COUNTS = Counts or count rate [counts/s]. DENSITY = Photographic density. OTHER = Described in a comment. CRVALn F Reference point for CTYPEn. CRPIXn F Reference pixel location corresponding to CRVALn. CDELTn F Increment in CTYPEn per pixel. ______________________________________________________________________________ In addition the FITS headers include a number of HISTORY, COMMENT, and related keywords. They are listed below. Table 7.2. HISTORY, COMMENT, and related keywords in the FITS headers ______________________________________________________________________________ Keyword Type Description ______________________________________________________________________________ HISTORY DATE-REC C Date the file was received by the SSN. HISTORY DATE-CMP C Date of completion of the file archiving HISTORY REDUCED C Known data reduction steps. HISTORY C Other history if known. COMMENT ADD.OBS. C Additional observers. COMMENT NOTE C Some important note on the data extracted from COMMENT or HISTORY fields to appear in the printed archive listing. COMMENT PROC FILE and ORIG. FILE C Comment regarding original file identifi cation of the submitted file. Often file name consists of position of file on original submission tape. Used for SSN archiving. COMMENT REPLACE C A note that this file supercedes another file (previous file would have been deleted from the archive). COMMENT C Additional comments about the data. DATAMAX F Maximum value of dependent variable. DATAMIN F Minimum value of dependent variable. BSCALE F Scale factor to convert FITS pixel value to true values. Used to convert FITS data to original data values: DataValue = BZERO + BSCALE* FileDataValue. BZERO F Offset applied to true pixel values. END C Signals end of FITS header. ______________________________________________________________________________ 8.0. AMATEUR OBSERVATIONS Table 8.0. Keywords for All Types of Data ______________________________________________________________________________ Keyword Description ______________________________________________________________________________ SIMPLE = T / THIS IS A FITS FILE BITPIX = 8 / BITS PER PIXEL NAXIS = 0 / NO IMAGE DATA ARRAY PRESENT EXTEND = T / THERE MAY BE STANDARD EXTENSIONS OBJECT = 'ooo...oo' / NAME OF OBJECT FILE-NUM= 8nnnnn / UNIQUE FILE IDENTIFICATION NO. DATE-OBS= 'dd/mm/yy' / DATE OF MIDDLE OF OBSERVATION (UT) TIME-OBS= .ttttt / TIME OF MIDDLE OF OBSERVATION (UT) DATE-REL= 'dd/mm/yy' / DATE OF PUBLIC RELEASE DISCIPLN= 'AMATEUR ' / IHW DISCIPLINE LONG-OBS= 'ddd/mm/ss' / EAST LONGITUDE OF OBSERVING SITE LAT--OBS= 'sdd/mm/ss' / LATITUDE OF OBSERVING SITE SYSTEM = '8nnnttii' / OBSERVING SYSTEM CODE OBSERVER= 'ooo...oo' / NAME OF OBSERVER SUBMITTR= 'sss...ss' / NAME OF SUBMITTER OF DATA SPEC-EVT= s / SPECIAL EVENT FLAG ______________________________________________________________________________ Table 8.1. Keywords for Visual Appearance Descriptions ______________________________________________________________________________ Keyword Description ______________________________________________________________________________ DAT-FORM= 'ASCII ' / FORM OF DATA DAT-TYPE= 'VISUAL MAG. EST.' / TYPE OF DATA ELEV-OBS= eeee / ELEVATION OF OBSERVING SITE (METER) INSTRUME= 'iii...ii' / TYPE OF INSTRUMENT USED APERTURE= a.aaa / APERTURE SIZE (METER) FRATIO = ff.f / FOCAL RATIO POWER = ppp / MAGNIFICATION ORIGIN = 'JET PROPULSION LAB' / TAPE WRITING INSTITUTION COMMENT ccc...cc : END XTENSION= 'TABLE ' / TABLE EXTENSION BITPIX = 8 / BITS PER PIXEL NAXIS = 2 / 2-D MATRIX NAXIS1 = 71 / NO. OF CHARACTERS PER ROW NAXIS2 = 1 / NO. OF ROWS PCOUNT = 0 / NO RANDOM PARAMETERS GCOUNT = 1 / ONLY ONE GROUP TFIELDS = 16 / NO. OF FIELDS PER ROW TTYPE1 = 'MAG. EST. METHOD' / VALUES: B=BOBROVNIKOFF, M=MORRIS, S=SIDGWICK TBCOL1 = 1 / STARTING COLUMN TFORM1 = 'A1 ' / FORMAT TNULL1 = '? ' / MISSING VALUE TTYPE2 = 'COMA MAGNITUDE' / TOTAL MAGNITUDE (GIVEN AS ALPHANUMERIC TBCOL2 = 3 / STARTING COLUMN STRING, SINCE 1ST COL. TFORM2 = 'A5 ' / FORMAT CAN BE > SIGN, WHICH TNULL2 = '-99.0 ' / MISSING VALUE IMPLIES UPPER LIMIT) TTYPE3 = 'MAGNITUDE COMMENT' / INDICATES UNCERTAINTY IF VALUE IS : OR ? TBCOL3 = 8 / STARTING COLUMN TFORM3 = 'A1 ' / FORMAT TNULL3 = ' ' / MISSING VALUE TTYPE4 = 'CHART NO.' / USED FOR COMPARISON STARS (SEE PRINTED CROM- TBCOL4 = 10 / STARTING COLUMN MELIN ARCHIVE OR TFORM4 = 'A7 ' / FORMAT INT'L. COMET QTRL. FOR EXPLA- NATION) TNULL4 = ' ' / MISSING VALUE TTYPE5 = 'COMA DIAMETER 1' / CIRCULAR COMA DIAM. (OR MAJOR AXIS, TBCOL5 = 18 / STARTING COLUMN ELLIPTICAL COMA) TFORM5 = 'E5.1 ' / FORMAT TUNIT5 = 'ARCMIN. ' / UNIT TNULL5 = '-99.0 ' / MISSING VALUE TTYPE6 = 'COMA DIAMETER 2' / MINOR AXIS, ELLIPTICAL COMA TBCOL6 = 24 / STARTING COLUMN TFORM6 = 'E5.1 ' / FORMAT TUNIT6 = 'ARCMIN. ' / UNIT TNULL6 = '-99.0 ' / MISSING VALUE (OR CIRCULAR COMA) TTYPE7 = 'DEGREE OF COND.' / DEGREE OF CONDENSATION TBCOL7 = 30 / STARTING COLUMN TFORM7 = 'I1 ' / FORMAT TNULL7 = ' ' / MISSING VALUE TTYPE8 = 'LENGTH OF TAIL 1' / TAIL LENGTH (1ST TAIL) TBCOL8 = 32 / STARTING COLUMN TFORM8 = 'E5.2 ' / FORMAT TUNIT8 = 'DEGREE ' / UNIT TNULL8 = '-9.00 ' / MISSING VALUE TTYPE9 = 'P.A. OF TAIL 1' / POSITION ANGLE OF TAIL (1ST TAIL) TBCOL9 = 38 / STARTING COLUMN TFORM9 = 'I3 ' / FORMAT TUNIT9 = 'DEGREE ' / UNIT TNULL9 = '-99 ' / MISSING VALUE TTYPE10 = 'LENGTH OF TAIL 2' / TAIL LENGTH (2ND TAIL, IF SEEN) TBCOL10 = 42 / STARTING COLUMN TFORM10 = 'E5.2 ' / FORMAT TUNIT10 = 'DEGREE ' / UNIT TNULL10 = '-9.00 ' / MISSING VALUE TTYPE11 = 'P.A. OF TAIL 2' / POSITION ANGLE OF TAIL (2ND TAIL, IF SEEN) TBCOL11 = 48 / STARTING COLUMN TFORM11 = 'I3 ' / FORMAT TUNIT11 = 'DEGREE ' / UNIT TNULL11 = '-99 ' / MISSING VALUE TTYPE12 = 'LENGTH OF TAIL 3' / TAIL LENGTH (3RD TAIL, IF SEEN) TBCOL12 = 52 / STARTING COLUMN TFORM12 = 'E5.2 ' / FORMAT TUNIT12 = 'DEGREE ' / UNIT TNULL12 = '-9.00 ' / MISSING VALUE TTYPE13 = 'P.A. OF TAIL 3' / POSITION ANGLE OF TAIL (3RD TAIL, IF SEEN) TBCOL13 = 58 / STARTING COLUMN TFORM13 = 'I3 ' / FORMAT TUNIT13 = 'DEGREE ' / UNIT TNULL13 = '-99 ' / MISSING VALUE TTYPE14 = 'LIMITING MAG.' / MAGNITUDE OF FAINTEST STAR VISIBLE TO NAKED EYE TBCOL14 = 62 / STARTING COLUMN TFORM14 = 'E4.1 ' / FORMAT TNULL14 = '-9.0 ' / MISSING VALUE TTYPE15 = 'SKY INTERFERENCE' / LIGHT INTERFERING WITH OBSERVATION TBCOL15 = 66 / STARTING COLUMN (C=CITY LIGHTS, M=MOONLIGHT, TFORM15 = 'A4 ' / FORMAT T=TWILIGHT, Z=ZODIACAL LIGHT) TNULL15 = ' ' / MISSING VALUE (NO INTERFERENCE) COMMENT VALUE EQUAL TO : IMPLIES UNCERTAINTY IN FAINTEST STAR MAG. TTYPE16 = 'DARK ADAPTED' / WAS OBSERVER DARK ADAPTED? (Y=YES, N=NO) TBCOL16 = 71 / STARTING COLUMN TFORM16 = 'A1 ' / FORMAT TNULL16 = ' ' / MISSING VALUE END ______________________________________________________________________________ Table 8.3. Keywords for Drawings ______________________________________________________________________________ Keyword Description ______________________________________________________________________________ DAT-FORM= 'NODATA ' / FORM OF DATA (NO DATA RECORDS) DAT-TYPE= 'DRAWING ' / TYPE OF DATA ELEV-OBS= eeee / ELEVATION OF OBSERVING SITE (METER) INSTRUME= 'iii...ii' / TYPE OF INSTRUMENT USED APERTURE= a.aaa / APERTURE SIZE (METER) FRATIO = ff.f / FOCAL RATIO N-POWER = n / NO. OF MAGNIFICATIONS USED POWER = ppp / MAGNIFICATION : MAG-LIM = m.m / MAGNITUDE OF FAINTEST STAR VISIBLE TO NAKED EYE PLTSCALE= ppp.p / PLATE (DRAWING) SCALE (ARCSEC/MM) DURATION= ddd / TIME FOR MAKING DRAWING (SECOND) ORIGIN = 'JET PROPULSION LAB' / TAPE WRITING INSTITUTION COMMENT ccc...cc : END ______________________________________________________________________________ Table 8.4. Keywords for Photographs ______________________________________________________________________________ Keyword Description ______________________________________________________________________________ DAT-FORM= 'NODATA ' / FORM OF DATA (NO DATA RECORDS) DAT-TYPE= 'PHOTOGRAPH' / TYPE OF DATA ELEV-OBS= eeee / ELEVATION OF OBSERVING SITE (METER) PRNCPLFL= p.ppp / PRIMARY, UNMODIFIED INSTR. FOCAL LENGTH (METER) TELEFL = t.ttt / EFFECTIVE FOCAL LENGTH (METER) APERTURE= a.aaa / APERTURE SIZE (METER) FRATIO = ff.f / FOCAL RATIO FOVLENGT= ff.f / COMPUTED FOV ASSUMING 135 FORMAT (DEGREE) FOVWIDTH= ff.f / COMPUTED FOV ASSUMING 135 FORMAT (DEGREE) PLTSCALE= ppp.p / PLATE SCALE (ARCSEC/MM) EMULSION= 'eee...ee' / TYPE OF EMULSION ISO = 'aaaa/dd ' / ISO (ASA/DIN) HYPERED = 'hhh...hh' / HYPERSENSITIZATION TREATMENT TEMP-HYP= tt / HYPERSENSITIZATION TEMPERATURE (CELSIUS) TIME-HYP= ttt.t / HYPERSENSITIZATION TIME (HOUR) TEMPEMUL= tt / COLD CAMERA TEMPERATURE (CELSIUS) DEVELOPR= 'ddd...dd' / DEVELOPER USED TEMP-DEV= tt / DEVELOPING TEMPERATURE (CELSIUS) TIME-DEV= ttt / DEVELOPING TIME (SECOND) GUIDING = 'ggg...gg' / GUIDING METHOD EXPOSURE= eeee / EXPOSURE TIME (SECOND) IM-ID = 'iii ' / IMAGE IDENTIFICATION NO. IM-TYPE = 'iii...ii' / TYPE OF IMAGE ON FILE ORIGIN = 'JET PROPULSION LAB' / TAPE WRITING INSTITUTION COMMENT ccc...cc : END ______________________________________________________________________________ Table 8.5. Keywords for Spectroscopy ______________________________________________________________________________ Keyword Description ______________________________________________________________________________ DAT-FORM= 'NODATA ' / FORM OF DATA (NO DATA RECORDS) DAT-TYPE= 'SPECTRUM' / TYPE OF DATA ELEV-OBS= eeee / ELEVATION OF OBSERVING SITE (METER) INSTRUME= 'iii...ii' / TYPE OF INSTRUMENT USED PRNCPLFL= p.ppp / PRIMARY, UNMODIFIED INSTR. FOCAL LENGTH (METER) TELEFL = t.ttt / EFFECTIVE FOCAL LENGTH (METER) APERTURE= a.aaa / APERTURE SIZE (METER) FRATIO = ff.f / FOCAL RATIO EMULSION= 'eee...ee' / TYPE OF EMULSION ISO = 'aaaa/dd ' / ISO (ASA/DIN) HYPERED = 'hhh...hh' / HYPERSENSITIZATION TREATMENT TEMP-HYP= tt / HYPERSENSITIZATION TEMPERATURE (CELSIUS) TIME-HYP= ttt.t / HYPERSENSITIZATION TIME (HOUR) TEMPEMUL= tt / COLD CAMERA TEMPERATURE (CELSIUS) DEVELOPR= 'ddd...dd' / DEVELOPER USED TEMP-DEV= tt / DEVELOPING TEMPERATURE (CELSIUS) TIME-DEV= ttt / DEVELOPING TIME (SECOND) GUIDING = 'ggg...gg' / GUIDING METHOD EXPOSURE= eeee / EXPOSURE TIME (SECOND) GRATING = ggg.g / GRATING CONSTANT (METER) ORDER = o / BLAZE ORDER APDSPRSR= a.aaaa / DISPERSER APERTURE (METER) PROJDIST= p.pppp / PROJECTION DISTANCE (METER) APEX-ANG= aaa / PRISM APEX ANGLE (DEGREE) GLASSTYP= 'ggg...gg' / PRISM GLASS TYPE AP-PRISM= a.aaaa / PRISM APERTURE (METER) METHOD = 'mmm...mm' / SPECTROSCOPIC METHOD IM-ID = 'iii ' / IMAGE IDENTIFICATION NO. IM-TYPE = 'iii...ii' / TYPE OF IMAGE ON FILE ORIGIN = 'JET PROPULSION LAB' / TAPE WRITING INSTITUTION COMMENT ccc...cc : END ______________________________________________________________________________ 9.0. METEOR STUDIES NETWORK Table 9.1. Main Header __________________________________________________________________________ KEYWORD EXPLANATION FORMAT __________________________________________________________________________ BITPIX = 8 \ 8-bit characters EXTEND = T \ Yes, a table DAT-FORM = 'ASCII ' OBJECT Name of meteor shower 'ORIONID' or 'ETA-AQUARID' FILE NUM = File number--Beginning with 9 and followed by a unique 5-digit num- ber DATE-OBS UT date of middle of observing pe- riod. See notes for shower periods 'DD/MM/YY' TIME-OBS UT time of middle of observation. Not significant for meteor observa- tions and therefore usually given as 0.0 DISCIPLN IHW Discipline 'METEOR STUDIES' SYSTEM Key to finding observing system in discipline/station catalog. Insti- tutes with long-standing observing instruments are listed in Attach- ment C '9uuuccnn' OBSERVER 'Onename,I' or or SUBMITTR 'Oneperson,J/Otherperson,K' or 'Firstperson,L/ET AL' if more than two DAT-FORM 'ASCII ' data are in character form, usually implying tables and BITPIX=8. OBSVTORY name of submitting observatory 'Tadjik Astrophy Inst' LOCATION location of submitting observatory 'Dushanbe, USSR' LIM-SENS threshold sensitivity for obser- vations not cataloged by SYSTEM. Given as limiting magnitude (pho- tographic, visual, or equivalent radio magnitude or electron line '+8M radio' density) '10**14 electron/m' QUALITY estimate of the quality of the ob- servation on a scale of: 1 = poor, to 5 = excellent, with 0 = unknown 2 __________________________________________________________________________ Table 9.2. Example of EXTENSION Header and Data for Radar Observations ___________________________________________________________________________ XTENSION= 'TABLE ' / table extension BITPIX = 8 / bits per character NAXIS = 2 / dimensions of table NAXIS1 = 100 / characters per line NAXIS2 = 193 / hours of observations PCOUNT = 0 / no random parameters GCOUNT = 1 / only one group TFIELDS = 35 / fields per line EXTNAME = 'ORIONIDS 86' / name of table COMMENT Description of the table columns. COMMENT There is one space between each field. TTYPE1 = 'YR ' / year TBCOL1 = 1 / starting column TFORM1 = 'I2 ' / 2-digit integer TTYPE2 = 'MO ' / month TBCOL2 = 4 / starting column TFORM2 = 'I2 ' / 2-digit integer TTYPE3 = 'DA ' / UT day TBCOL3 = 7 / starting column TFORM3 = 'I2 ' / 2-digit integer TTYPE4 = 'HR ' / UT hour TBCOL4 = 10 / starting column TFORM4 = 'I2 ' / 2-digit integer TTYPE5 = 'TOTAL ' / total hour count TBCOL5 = 13 / starting column TFORM5 = 'I3 ' / 3-digit integer TTYPE6 = '>=1sec ' / count for durations >=1 sec TBCOL6 = 17 / starting column TFORM6 = 'I3 ' / 3-digit integer TTYPE7 = '>=8sec ' / count for durations >=8 sec TBCOL7 = 21 / starting column TFORM7 = 'I2 ' / 2-digit integer TTYPE8 = ' 75 ' / count in 10km range class 70-80 km TBCOL8 = 24 / starting column TFORM8 = 'I1 ' / 1-digit integer TTYPE9 = ' 85 ' / count in 10km range class TBCOL9 = 26 / starting column TFORM9 = 'I2 ' / 2-digit integer TTYPE10 = ' 95 ' / count in 10km range class TBCOL10 = 29 / starting column TFORM10 = 'I2 ' / 2-digit integer TTYPE11 = '105 ' / count in 10km range class TBCOL11 = 32 / starting column TFORM11 = 'I2 ' / 2-digit integer TTYPE12 = '115 ' / count in 10km range class TBCOL12 = 35 / starting column TFORM12 = 'I2 ' / 2-digit integer TTYPE13 = '125 ' / count in 10km range class TBCOL13 = 38 / starting column TFORM13 = 'I2 ' / 2-digit integer TTYPE14 = '135 ' / count in 10km range class TBCOL14 = 41 / starting column TFORM14 = 'I2 ' / 2-digit integer TTYPE15 = '145 ' / count in 10km range class TBCOL15 = 44 / starting column TFORM15 = 'I2 ' / 2-digit integer TTYPE16 = '155 ' / count in 10km range class TBCOL16 = 47 / starting column TFORM16 = 'I2 ' / 2-digit integer TTYPE17 = '165 ' / count in 10km range class TBCOL17 = 50 / starting column TFORM17 = 'I2 ' / 2-digit integer TTYPE18 = '175 ' / count in 10km range class TBCOL18 = 53 / starting column TFORM18 = 'I2 ' / 2-digit integer TTYPE19 = '185 ' / count in 10km range class TBCOL19 = 56 / starting column TFORM19 = 'I2 ' / 2-digit integer TTYPE20 = '195 ' / count in 10km range class TBCOL20 = 59 / starting column TFORM20 = 'I2 ' / 2-digit integer TTYPE21 = '205 ' / count in 10km range class TBCOL21 = 62 / starting column TFORM21 = 'I2 ' / 2-digit integer TTYPE22 = '215 ' / count in 10km range class TBCOL22 = 65 / starting column TFORM22 = 'I2 ' / 2-digit integer TTYPE23 = '225 ' / count in 10km range class TBCOL23 = 68 / starting column TFORM23 = 'I2 ' / 2-digit integer TTYPE24 = '235 ' / count in 10km range class TBCOL24 = 71 / starting column TFORM24 = 'I2 ' / 2-digit integer TTYPE25 = '245 ' / count in 10km range class TBCOL25 = 74 / starting column TFORM25 = 'I2 ' / 2-digit integer TTYPE26 = '255 ' / count in 10km range class TBCOL26 = 77 / starting column TFORM26 = 'I2 ' / 2-digit integer TTYPE27 = '265 ' / count in 10km range class TBCOL27 = 80 / starting column TFORM27 = 'I2 ' / 2-digit integer TTYPE28 = '275 ' / count in 10km range class TBCOL28 = 83 / starting column TFORM28 = 'I2 ' / 2-digit integer TTYPE29 = '285 ' / count in 10km range class TBCOL29 = 86 / starting column TFORM29 = 'I2 ' / 2-digit integer TTYPE30 = '295 ' / count in 10km range class TBCOL30 = 89 / starting column TFORM30 = 'I2 ' / 2-digit integer TTYPE31 = '305 ' / count in 10km range class TBCOL31 = 92 / starting column TFORM31 = 'I1 ' / 1-digit integer TTYPE32 = '315 ' / count in 10km range class TBCOL32 = 94 / starting column TFORM32 = 'I1 ' / 1-digit integer TTYPE33 = '325 ' / count in 10km range class TBCOL33 = 96 / starting column TFORM33 = 'I1 ' / 1-digit integer TTYPE34 = '335 ' / count in 10km range class TBCOL34 = 98 / starting column TFORM34 = 'I1 ' / 1-digit integer TTYPE35 = '345 ' / count in 10km range class TBCOL35 = 100 / starting column TFORM35 = 'I1 ' / 1-digit integer END __________________________________________________________________________ Table 9.3. Example of EXTENSION Header and Data for Visual Observations __________________________________________________________________________ XTENSION= 'TABLE ' / table extension BITPIX = 8 / bits per character NAXIS = 2 / dimensions of table NAXIS1 = 40 / characters per line NAXIS2 = 134 / number of lines in the table PCOUNT = 0 / no random parameters GCOUNT = 1 / only one group TFIELDS = 10 / fields per line EXTNAME = 'ETA-AQUARIDS85' / name of table COMMENT Description of the table columns. TTYPE1 = 'YR ' / year TBCOL1 = 3 / starting column TFORM1 = 'I2 ' / 2-digit integer TTYPE2 = 'MO ' / month TBCOL2 = 6 / starting column TFORM2 = 'I2 ' / 2-digit integer TTYPE3 = 'DAY ' / UT day & fraction TBCOL3 = 10 / starting column TFORM3 = 'E5.2 ' / 5-DIGIT 2 DECIMAL PLACES TTYPE4 = 'TIME ' / total minute count TBCOL4 = 16 / starting column TFORM4 = 'I3 / 3-digit integer TTYPE5 = 'OBS ' / observer number TBCOL5 = 20 / starting column TFORM5 = 'I3 ' / 3-digit integer TTYPE6 = 'SITE ' / site number TBCOL6 = 24 / starting column TFORM6 = 'I3 ' / 3-digit integer TTYPE7 = 'F-STAR ' / faintest magnitude visible TBCOL7 = 29 / starting column TFORM7 = 'E3.1 ' / 3-digit 1 decimal place TTYPE8 = 'CLOUD ' / cloud cover in % TBCOL8 = 33 / starting column TFORM8 = 'I2 ' / 2-digit integer TTYPE9 = 'NUM-SH ' / count shower meteors TBCOL9 = 35 / starting column TFORM9 = 'I3 ' / 3-digit integer TTYPE10 = 'NUM-NS ' / count non-shower meteors TBCOL10 = 38 / starting column TFORM10 = 'I3 ' / 3-digit integer END ______________________________________________________________________________