CCSD3ZF0000100000001NJPL3IF0PDSX00000001 PDS_VERSION_ID = PDS3 /* File Format and Length */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 78 FILE_RECORDS = 2684 DATA_SET_ID = "IRAS-D-FPA-3-RDR-ZOHF-MEDIUM-RES-V1.0" DATA_SET_NAME = "IRAS MEDIUM RESOLUTION ZODIACAL HISTORY FILE V1.0" PRODUCT_ID = "SOP 164 OBS 21" /* Record Pointer to Major Object */ ^TABLE = "B_164_21.TAB" /* Description of Object in File */ OBSERVATION_ID = 164.21 NATIVE_START_TIME = 72315628.7 NATIVE_STOP_TIME = 72317361.8 ORBIT_NUMBER = 1144 SOLAR_ELONGATION = 87.734811 SOLAR_ELONGATION_SIGMA = 9.2189E-04 IRAS_CLOCK_ANGLE_START = 6.590236 IRAS_CLOCK_ANGLE_RANGE = 111.250757 IRAS_CLOCK_ANGLE_RATE = 6.4194E-02 IRAS_CLOCK_ANGLE_RATE_SIGMA = 2.6043E-04 START_ECLIPTIC_LATITUDE = 83.032959 STOP_ECLIPTIC_LATITUDE = -27.817351 SOLAR_LONGITUDE = 26.927126 IRAS_HCON = 1 OBJECT = TABLE ROWS = 2684 ROW_BYTES = 78 INTERCHANGE_FORMAT = ASCII COLUMNS = 8 DESCRIPTION = "The IRAS Medium-Resolution (2 arcminute in-scan) Zodiacal Observational History File (ZOHF) consists of the time-ordered IRAS survey data averaged into 2' X 1/2 degree rectangular pixels along with pointing and timing information, covering the entire mission. These pixels contain the average of all detector samples in a given wavelength band summed over a time corresponding to a 2 arcminute scan. The data used in generating this file (Version 2) is not identical to that used in generating the 1/2 X 1/2 degree ZOHF (Version 3). An explanation of the differences in calibration between the two data sets and a statistical analysis of the differences in the resultant positions and fluxes may be found in Oken et al. (1988) and Boulanger (1988). General information about the Infrared Astronomical Satellite (IRAS) and its mission may be found in Beichman et al. (1989) and Neugebauer et al. (1984). " NOTE = " While generally characterized as being 2' x 1/2 degree pixels, the actual pixel dimensions (in arc-minutes) are as follows: Band Wavelength In-Scan Cross-Scan 1 12 1.925 28.4 2 25 1.925 30.3 3 60 1.925 28.5 4 100 1.925 30.5 (Oken et al. 1988)." OBJECT = COLUMN NAME = SAMPLE_TIME UNIT = SECOND DESCRIPTION = " The time associated with a given pixel corresponds to the sample time of the first (100 micron) detector averaged into that pixel measured in seconds since 0 hours Universal Time Coordinated, 1 January 1981 (Beichman et al. 1989). The position and timing information of even numbered scans was derived by averaging the positions and times of the samples on either side or, if it is the last sample of a scan, extrapolating from the previous samples. Time values may be off by as much as 2 seconds." NOTE = "The elapsed time does NOT correspond to the time at which the satellite boresight crosses the given pixel location." DATA_TYPE = REAL START_BYTE = 1 BYTES = 11 FORMAT = "F11.2" END_OBJECT OBJECT = COLUMN NAME = INCLINATION_OBSERVATION DESCRIPTION = "The angle (INCL) between the ecliptic plane and the plane containing the Earth, Sun, and observation direction (i.e., the azimuth angle about the Earth-Sun axis) (Beichman et al. 1989). INCL is zero as the satellite looks at the ecliptic plane in the direction opposite to the motion of the Earth around the Sun. It increases clockwise along the Earth-Sun axis, facing the Sun - opposite from the direction of motion of the satellite in its orbit about the Earth. The position and timing information of even numbered scans was derived by averaging the positions and times of the samples on either side or, if it is the last sample of a scan, extrapolating from the previous samples. In units of degrees, INCL is related to clock angle (CL) by the relation INCL=90-CL. INCL also is related to geocentric ecliptic latitude (BETA) through the relation SIN(BETA)=SIN(INCL)SIN(SE), where SE is the solar elongation of observation." DATA_TYPE = REAL START_BYTE = 13 BYTES = 6 FORMAT = "F6.2" END_OBJECT OBJECT = COLUMN NAME = BETA UNIT = DEGREE DESCRIPTION = "The geocentric ecliptic latitude (Equinox 1950.0, Epoch 1983.5) of observation. The precision of the value corresponds to one-third a pixel width. The position and timing information of even numbered scans was derived by averaging the positions and times of the samples on either side or, if it is the last sample of a scan, extrapolating from the previous samples." DATA_TYPE = REAL START_BYTE = 20 BYTES = 6 FORMAT = "F6.2" END_OBJECT OBJECT = COLUMN NAME = LAMBDA UNIT = DEGREE DESCRIPTION = "The geocentric ecliptic longitude (Equinox 1950.0, Epoch 1983.5) of observation. This is related to the solar elongation of observation (SE) and geocentric ecliptic latitude and the geocentric ecliptic longitude of the sun (LSUN) through the relation COS(SE)=COS(BETA)COS(LAMBDA-LSUN).The position and timing information of even numbered scans was derived by averaging the positions and times of the samples on either side or, if it is the last sample of a scan, extrapolating from the previous samples." DATA_TYPE = REAL START_BYTE = 27 BYTES = 6 FORMAT = "F6.2" END_OBJECT OBJECT = COLUMN NAME = FLUX_12 UNIT = "JANSKY PER STERADIAN" DESCRIPTION = "Flux densities (1 Jy = 1.e-26 Watt/ (meter*2)Hz) are calculated from inband flux (Watts/meter^2) assuming the external source function to be proportional to 1/frequency. Jy (BD) at 12 microns is converted to Watt/(meter^2) (IB) by the relation BD*K=IB, where K=1.348e-13 (Moshir et al 1989)." DATA_TYPE = REAL START_BYTE = 34 BYTES = 10 FORMAT = "E10.4" END_OBJECT OBJECT = COLUMN NAME = FLUX_25 UNIT = "JANSKY PER STERADIAN" DESCRIPTION = "Flux densities (1 Jy = 1.e-26 Watt/ (meter*2)Hz) are calculated from inband flux (Watts/meter^2) assuming the external source function to be proportional to 1/frequency. Jy (BD) at 25 microns is converted to Watt/(meter^2) (IB) by the relation BD*K=IB, where K=5.155e-14 (Moshir et al 1989)." DATA_TYPE = REAL START_BYTE = 45 BYTES = 10 FORMAT = "E10.4" END_OBJECT OBJECT = COLUMN NAME = FLUX_60 UNIT = "JANSKY PER STERADIAN" DESCRIPTION = "Flux densities (1 Jy = 1.e-26 Watt/ (meter*2)Hz) are calculated from inband flux (Watts/meter^2) assuming the external source function to be proportional to 1/frequency. Jy (BD) at 60 microns is converted to Watt/(meter^2) (IB) by the relation BD*K=IB, where K=2.577e-14 (Moshir et al 1989)." DATA_TYPE = REAL START_BYTE = 56 BYTES = 10 FORMAT = "E10.4" END_OBJECT OBJECT = COLUMN NAME = FLUX_100 UNIT = "JANSKY PER STERADIAN" DESCRIPTION = "Flux densities (1 Jy = 1.e-26 Watt/ (meter*2)Hz) are calculated from inband flux (Watts/meter^2) assuming the external source function to be proportional to 1/frequency. Jy (BD) at 100 microns is converted to Watt/(meter^2) (IB) by the relation BD*K=IB, where K=1.e-14 (Moshir et al 1989)." DATA_TYPE = REAL START_BYTE = 67 BYTES = 10 FORMAT = "E10.4" END_OBJECT END_OBJECT = TABLE END