CCSD3ZF0000100000001NJPL3IF0PDS200000001 = SFDU_LABEL /* File Format and Length */ PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 47 FILE_RECORDS = 167 DATA_SET_ID = "GIO-C-DID-3-RDR-HALLEY-V1.0" OBSERVATION_ID = "89007" TARGET_NAME = "HALLEY" OBSERVATION_TIME = 1986-03-13T23:31:12.000Z START_TIME = "UNK" /* Record Pointer to Object */ ^TABLE = "DSUMMARY.TAB" /* Description of Object in File */ OBJECT = TABLE ROWS = 167 ROW_BYTES = 47 INTERCHANGE_FORMAT = ASCII NOTE = "Created by FITS2PDS" DESCRIPTION = " CUMULATIVE FLUXES FROM DISCRETE DATA FOR 10 TIME PE DIDSY DISCRETE DATA ARE A SUBSET OF THE LARGE MASS PARTICLES DETECTED. THEY CONSIST OF UP TO FOUR IMPACTS PER DATA GATHERING INTERVAL (1.13S) FOR WHICH SIGNALS FROM 2 OR MORE SENSORS ARE AVAILABLE. THIS ALLOWS AN ACTUAL MASS TO BE DERIVED. THE UNCERTAINTY IN MASS FOR AN INDIVIDUAL PARTICLE MAY BE HIGH, BUT FOR >10 IMPACTS THE DISTRIBUTION OF MASSES IS REPRESENTATIVE OF THE TRUE POPULATION (C.PERRY PHD). DATA ARE PRESENTED IN 10 TIME PERIODS (~50% OVERLAP) AS GIVEN IN TABLE: PERIOD START TIME END TIME NO OF IMPACTS 1 22:59:50 (-4272S) 00:08:52 (-130S) 20 2 00:04:32 (-390S) 00:09:52 (-70S) 20 3 00:08:53 (-129S) 00:10:19 (-43S) 21 4 00:09:53 (-69S) 00:10:36 (-26S) 20 * 5 00:10:20 (-42S) 00:10:47 (-18S) 19 * 6 00:10:37 (-25S) 00:10:47 (-15S) 18 * 7 00:11:18 (+16S) 00:11:41 (+39S) 15 * 8 00:11:28 (+26S) 00:12:42 (+100S) 14 * 9 00:11:42 (+40S) 00:13:02 (+120S) 12 10 00:12:43 (+100S) 01:01:02 (+3000S) 8 PERIODS MARKED * HAVE LARGER UNCERTAINTIES IN MASS DUE TO THE HIGH FLUX OF SMALLER PARTICLES WHICH CAN CAUSE FALSE COINCIDENCE. MASSES FOR EACH DISCRETE IMPACT WERE CALCULATED WITH MOMENTUM ENHANCEM- ENT OF E=11 FOR NON-PENETRATING PARTICLES: P(MEASURED)=E*P(TRUE). FOR PARTICLES WHICH PENETRATE THE FRONT SHIELD THE MEASURED MOMENTUM IS DERATED: P(MEASURED)=E*P(TRUE)*(MPEN/M)**G WHERE MPEN=PENETRATION MASS (3E-9KG) AND G=MOMENTUM DERATING EXPONENT. A VALUE OF G=0.4 WAS USED HERE. MEAN TIME AND DISTANCE QUOTED ARE MEANS IN LOG(DISTANCE) SPACE. FLUXES FOR TIMES WITHIN 60 SECONDS OF ENCOUNTER ARE CORRECTED FOR INCOMPLETE SAMPLING BY COMPARISON WITH BINNED DATA." COLUMNS = 8 OBJECT = COLUMN NAME = "MEAN_HR" DESCRIPTION = "GROUND RECEIVED TIME" DATA_TYPE = ASCII_INTEGER BYTES = 2 UNIT = "HOUR" START_BYTE = 1 FORMAT = I2 END_OBJECT OBJECT = COLUMN NAME = "MIN" DESCRIPTION = "GROUND RECEIVED TIME" DATA_TYPE = ASCII_INTEGER BYTES = 2 UNIT = "MIN" START_BYTE = 4 FORMAT = I2 END_OBJECT OBJECT = COLUMN NAME = "SEC" DESCRIPTION = "GROUND RECEIVED TIME" DATA_TYPE = ASCII_REAL BYTES = 4 UNIT = "SEC" START_BYTE = 7 FORMAT = "F4.1" END_OBJECT OBJECT = COLUMN NAME = "MEAN_DISTANCE" DESCRIPTION = "COMETOCENTRIC" DATA_TYPE = ASCII_INTEGER BYTES = 6 UNIT = "KM" START_BYTE = 12 FORMAT = I6 END_OBJECT OBJECT = COLUMN NAME = "COUNTS" DATA_TYPE = ASCII_INTEGER BYTES = 2 START_BYTE = 20 FORMAT = I2 END_OBJECT OBJECT = COLUMN NAME = "MASS" DATA_TYPE = ASCII_REAL BYTES = 9 UNIT = "KG" START_BYTE = 23 FORMAT = "E9.3" END_OBJECT OBJECT = COLUMN NAME = RADIANT_FLUX DATA_TYPE = ASCII_REAL BYTES = 9 UNIT = "M**_2.SEC**_1" START_BYTE = 33 FORMAT = "E9.3" END_OBJECT OBJECT = COLUMN NAME = "ERROR" DATA_TYPE = ASCII_INTEGER BYTES = 3 UNIT = "PERCENT" START_BYTE = 43 FORMAT = I3 END_OBJECT END_OBJECT = TABLE END