Document title: VOLDESC.SFD for NDADS DE HAPI SATM data Project: DE NDADS Datatype: HAPI Super-EID: DOCUMENT There may be other documents also identified by this super-EID. NDADS filename: HAPI_VOLDESC.SFD TRF entry: B46591.txt in NSSDC's controlled digital document library, Feb. 1998. Document text follows: ---------------------- CCSD3ZF0000100000001CCSD3VS00002MRK**001 LOG_VOL_IDENT: USANASANSSDDEA5-0001C LOG_VOL_INITIATION_DATE: 1992-12-03 LOG_VOL_CLOSING_DATE: YYYY-MM-DD LOG_VOL_CAPACITY: 1 GB/LOGICAL_VOL LOG_VOL_FILE_STRUCTURE: FILES-11 VOLUME_DIAMETER: 12 INCHES VOLUME_DRIVE_MFGR_AND_MODEL: OPTIMUM 1000 WITH 1.6 CONTROLLER COMPUTER_MANUFACTURER: DIGITAL EQUIPMENT CORPORATION OPERATING_SYSTEM: MICROVMS 5.4 COMPUTER_SYSTEM: MICRO VAX II TRANSFER_SOFTWARE: SOAR 4.2 TECHNICAL_CONTACTS: ROBERT M. CANDEY NASA/GSFC CODE 632 GREENBELT, MD 20771 PHONE: 1-301-286-6707 SPAN: NCF::CANDEY INTERNET: ROBERT.M.CANDEY.1@GSFC.NASA.GOV PREV_LOG_VOLS: USANASANSSDDEA5-0001A USANASANSSDDEA5-0001B CCSD$$MARKERMRK**001CCSD3SS00002MRK**002 DATA_SET_NAME: HAPI SATM file. (SATM = Stand Alone Telemetry) DATA_SOURCES: DYNAMICS EXPLORER A, HIGH ALTITUDE PLASMA INSTRUMENT (HAPI) SCIENTIFIC_CONTACTS: DR. J. L. BURCH / DR. R. A. HOFFMAN DEPT. OF SPACE SCIENCES CODE 696 SOUTHWEST RESEARCH INST. NASA/GSFC P.O. DRAWER 28510 GREENBELT, MD 20771 SAN ANTONIO, TX 78284 PHONE: 301-286-7386 SPAN DE696::U6RAH SOURCE_CHARACTERISTICS: A. DESCRIPTION_OF_SPACECRAFT: The Dynamics Explorer 1 spacecraft was one of two satellites launched for the Dynamics Explorer program. The two spacecraft were launched together into coplanar polar orbits for the purpose of studying coupling between the magnetosphere, ionosphere, and the atmosphere. The DE-1 spacecraft was placed in a highly elliptical orbit whereas the DE-2 spacecraft had an orbit with low ellipticity. Instruments aboard the DE-1 spacecraft were: magnetometer (MAGA), plasma wave instrument (PWI), spin-scan auroral imager (SAI), retarding ion mass spectrometer (RIMS), high-altitude plasma instrument (HAPI), and hot plasma composition instrument (EICS - energetic ion composition spectrometer). B. ORBIT_INFORMATION: Because the Delta launch vehicle did not complete a full burn, the DE-1 satellite was placed in a lower than anticipated polar orbit, initially 23173 by 570 km. The orbital period was 409 min. The DE-1 and DE-2 satel- lites were launched by the same vehicle so that their orbits would be coplanar, allowing occasional two-point measurements along magnetic field lines. The DE-1 spacecraft spun at a rate of 10 rpm and the spin axis was perpendicular to the orbital plane. The apogee latitude precessed through 360 degrees in 3 years. The apogee was positioned over the north pole on September 8, 1981. C. PERFORMANCE: The DE-1 spacecraft performed well through its lifetime. The launch was on Aug. 3, 1981 and the satellite ceased science operations on Feb. 26, 1991. Power limitations forced the duty cycle to be limited such that the instruments were not on continuously. The initial average duty cycle was over 90%, but this decreased over the lifetime to about 20% at the end of life. INVESTIGATION_OBJECTIVES: The objectives of the High Altitude Plasma investigation are to contribute to the Dynamics Explorer mission goals to provide high-resolution phase-space measurements of electrons and positive ions over the energy range from 5 eV to 32 keV. These measurements, along with supporting measurements from other instruments on DE-A and DE-B, primarily address the identification of the charge carriers of Birkeland currents by the high-latitude plasma populations, the transport of plasma through the mid-altitude cusp and into the polar cap, the upward mass flow from the ionosphere into the hot plasma population of the magnetosphere, and resonant interactions between hot plasma and natural and artificially-injected plasma waves and electromagnetic waves. ( Refer to J. L. Burch et. al., Space Science Instrumentation Vol. 5, No. 4, 1981, pp. 455-456). INSTRUMENT_ATTRIBUTES: A. DESCRIPTION_OF_INSTRUMENT: The High Altitude Plasma Instrument (HAPI) consisted of an array of 5 parabolic electrostatic analyzers lying in a plane containing the spacecraft spin axis, and spanning 90 degrees in angle. Each parabolic analyzer was followed by two channel electron multipliers to measure simultaneously electrons and positive ions. The basic mode of operation provided a 32-point energy spectrum every one-half second between 5 eV and 32 keV by stepping through 32 sets of voltages on the analyzer plates on a logarithmic scale each half second. No more than 8 of the 10 sensors were used at one time; typically, 3 electron and 5 ion detectors were monitored. The detectors sampled, sampling rate, voltage levels, etc. could be changed on command allowing a large variety of modes. B. OPERATIONAL_MODE: Operation modes were normally selected to emphasize either high angular resolution or high temporal (and spatial) resolution. 1. HIGH_ANGULAR_RESOLUTION_MODE: In this mode, the programmable power supply (PPS) was stepped each time a nadir pulse was received from the spacecraft. That is, a single energy was sampled every 0.93 degree for an entire spacecraft spin period. This mode was used primarily near apogee for studies of the loss-cone effects of wave-particle interactions and for detection of ion beams produced by the upward acceleration of ionospheric ions. 2. HIGH_TEMPORAL_RESOLUTION_MODE: In this mode, multiple energy spectra were required during each spacecraft spin. Typically 24 16-point energy spectra, each covering 15 degree of spacecraft spin were measured during each spin period. An increase to 32 energy steps, covering the full energy range of the instrument, decreased the angular resolution to 30 degrees of spacecraft spin. C. MEASURED_PARAMETERS: Outputs from pulse amplifiers in the detector modules were converted into an 8-bit compressed telemetry word using a quasi-logarithmic compression scheme. A decompression algorithm is used to calculate a decimal count rate, and with appropriate geometric factors, accumulation times and detector efficiencies, various types of fluxes can be derived as a function of energy. These fluxes are described in the file FORMAT.SFD and include the calculations via software provided of the differential number flux, the differential energy flux, and the phase space density. The distribution function can be derived from the phase space density data by contouring the density in velocity space. Software is not provided for this last calculation. D. PERFORMANCE_OF_THE_INSTRUMENT: The HAPI instrument initially performed very well after the spacecraft was launched. However, no data were received after December 1, 1981 due to high voltage power failure. E. RESOLUTION: Each SATM record contains one DE-1 major telemetry frame (8 seconds) of data. The HAPI stepping power supply always provided voltages to the electrostatic analyzers at a rate of 64 steps per second. It had the capability of producing a staircase of 64 different steps to cover the energy range from 5 eV to 32 keV on a logarithmic scale. However, typically 32 (or 16) of the steps were used by skipping some of the steps, allowing two (or four) sweeps through the energy range per second. PARAMETERS: The SATM files contain: The date and time of the start of each record, the number of sensors which were operating, each sensor's ID number, the energy step rate, skip rate, start step, and stop step, orbit/attitude information, nadir pulse times, magnetic field data, counts from the sensors, and energy step numbers. ( Refer to Dynamics Explorer-1, HAPI/LAPI Data Processing Software System I. High Altitude Plasma Instrument (HAPI), CSC documentation CSC/TM-82/6132, Section 2). It should be noted that the SATM files do not contain geophysically meaningful parameters from the HAPI instrument. Such parameters, as described in (C. MEASURED PARAMETERS), are obtained via the software provided which reads the SATM files and calculates the parameters. The magnetic field parameters are only used for the calculation of the pitch angles of the detectors. DATA_SET_QUALITY: There have been few problems with data quality. There is about a 5% error in the calibration. DATA_PROCESSING_OVERVIEW: A. DATA_PROCESSING_CYCLE: The Stand Alone Telemetry (SATM) files were generated directly from DE-1 Telemetry files stored on optical disks and merged with orbit data from the DE Orbit/Attitude database. B. HISTORY: The original HAPI SATM file database was generated on the DE Sigma-9 computer. The Sigma-9 software had problems dealing with time gaps and telemetry errors, and produced fragmented files (several files per pass). Mission Analysis Files (MAFs) were also generated on the Sigma-9 and used for analysis and plotting. In 1992, the HAPI SATM database was regenerated on a microVax computer to correct these problems. Only a few of the old Sigma-9 files are still in use where new SATM files could not be generated. However these have been converted to the new SATM format. These are marked by the letter D in the SATM file name. (See NAMING_CONVENTION.) These SATM files may be incomplete. The rest of the old Sigma-9 files, as well as MAFs are no longer in use. A new, more efficient file structure was used allowing easier access and reducing file size. See the file FORMAT.SFD for information concerning the HAPI SATM files. DATA_SET_NAME: HAPI STAND-ALONE TELEMETRY FILES (SATM) DATA_USAGE: DATA_ORGANIZATION: Are described in FORMAT.SFD . TIME_SPAN_OF_THE_DATA: 20-AUG-1981 TO 01-DEC-1981 TYPE_OF_FILE_RELATIONSHIP: All the HAPI instrument data are contained in SATM files. TIME_GAPS: There are occasionally time gaps between major frames. This is due to the fact that bad major frames were not written to the SATM files. Care should be taken in checking for time gaps when analyzing the data. SOFTWARE_TO_UNPACK_THE_DATA: The utility is included in HLAPI_SOFTWARE.TAR-GZ that must be uncompressed and untarred (zcat hlapi_software.tar-gz | tar xvf -) and stored in your local directory. Instructions on how to use the software can be found in the file HOW_TO_USE_REDUCE_SATM.TXT in the HAPI directory. SOFTWARE_APPLICATION_SCOPE: This utility applies to all the data files, i.e. those that can be named (using wildcards, and "/" to denote directory levels) /HAPI/8*/*.SATM . CCSD$$MARKERMRK**002CCSD3KS00002MRK**003 LOG_VOL_COVERAGE: 1981-11-05 TO 1981-12-01 General Note: Inspecting the names of the directories that are subordinate to the HAPI directory will directly indicate the dates of the data covered in the given volume. For example, on the first side (HAPI01) one of the directories is named: 81228_81257 This means that the data covered in the directory is "from 1981, 228th day through 1981, 257th day, inclusive." The three platter-sides are named HAPI01, HAPI02, and HAPI03. The directories on the three platter-sides are: (HAPI01) (HAPI02) (HAPI03) 81228_81257 81285_81288 81309_81312 81258_81263 81289_81292 81313_81316 81264_81269 81293_81296 81317_81321 81270_81275 81297_81300 81322_81325 81276_81279 81301_81304 81326_81330 81280_81284 81305_81308 81331_81335 There are two files that list the names/time-coverages/directories of the data files (*.SATM). One of these files lists this information for the "current" platter-side, and the other file lists this for all three platter sides. The format of these two lists is the same, and is described in the file LISTFORM.SFD . TYPES_OF_DATA_FILES_INCLUDED: HAPI SATM FILES ONLY SATM_TIME_COVERAGE: 1981-11-05T01:30:51 TO 1981-12-01T12:57:37 NAMING_CONVENTION: The start day and time are encoded in the HAPI SATM filename. Each HAPI SATM filename is in the following format: 'HyrdayhhmmB.SATM' H - indicates a HAPI file ( all files in this dataset are H) yr - the last two digits of the year, i.e., 81 for 1981 day - the Julian day (Jan 1 = 001) hh - the starting hour of the file mm - the starting minute of the file B - the production version of the file. Most files in this data set are B, the few files from the Sigma-9 are D. Further information may be found in DATA_PROCESSING_OVERVIEW (above), in subsection B, "HISTORY". SATM - the extension, indicating it is a Stand Alone Telemetry file For example: H812820506B.SATM would be a HAPI SATM file which started at 5:06 on Julian day 282 in 1981. FILE_TIME_COVERAGE: See LOG_VOL_COVERAGE, above, and See NAMING_CONVENTION, above, and See file THIS_SIDE_.DATA_FILE_LIST, and See file ALL_3_SIDES.DATA_FILE_LIST. OTHER_LOG_VOL_COVERAGE: 1981-08-16 TO 1981-10-11 1981-10-12 TO 1981-11-04 CCSD$$MARKERMRK**003CCSD3RF0000300000001 REFERENCETYPE=$CCSDS2; LABEL=ATTACHED; REFERENCE="/HAPI/FORMAT.SFD"; REFERENCE="/HAPI/LISTFORM.SFD"; LABEL=CCSD3SF0000200000001; REFERENCE="/HAPI/HLAPI_SOFTWARE.TAR-GZ-*"; REFERENCE="/HAPI/HOW_TO_USE_REDUCE_SATM.TXT-*"; LABEL=NSSD3IF0018400000001; REFERENCE="/HAPI/81309_81312/*.SATM-*"; REFERENCE="/HAPI/81313_81316/*.SATM-*"; REFERENCE="/HAPI/81317_81321/*.SATM-*"; REFERENCE="/HAPI/81322_81325/*.SATM-*"; REFERENCE="/HAPI/81326_81330/*.SATM-*"; REFERENCE="/HAPI/81331_81335/*.SATM-*"; LABEL=NSSD3KF0012900000001; REFERENCE="/HAPI/THIS_SIDE.DATA_FILE_LIST-*"; REFERENCE="/HAPI/ALL_3_SIDES.DATA_FILE_LIST-*"; /* (EOF) */ CCSD3ZF0000100000001CCSD3VS00002MRK**001 LOG_VOL_IDENT: USANASANSSDDEA5-0001C LOG_VOL_INITIATION_DATE: 1992-12-03 LOG_VOL_CLOSING_DATE: YYYY-MM-DD LOG_VOL_CAPACITY: 1 GB/LOGICAL_VOL LOG_VOL_FILE_STRUCTURE: FILES-11 VOLUME_DIAMETER: 12 INCHES VOLUME_DRIVE_MFGR_AND_MODEL: OPTIMUM 1000 WITH 1.6 CONTROLLER COMPUTER_MANUFACTURER: DIGITAL EQUIPMENT CORPORATION OPERATING_SYSTEM: MICROVMS 5.4 COMPUTER_SYSTEM: MICRO VAX II TRANSFER_SOFTWARE: SOAR 4.2 TECHNICAL_CONTACTS: ROBERT M. CANDEY NASA/GSFC CODE 632 GREENBELT, MD 20771 PHONE: 1-301-286-6707 SPAN: NCF::CANDEY INTERNET: ROBERT.M.CANDEY.1@GSFC.NASA.GOV PREV_LOG_VOLS: USANASANSSDDEA5-0001A USANASANSSDDEA5-0001B CCSD$$MARKERMRK**001CCSD3SS00002MRK**002 DATA_SET_NAME: HAPI SATM file. (SATM = Stand Alone Telemetry) DATA_SOURCES: DYNAMICS EXPLORER A, HIGH ALTITUDE PLASMA INSTRUMENT (HAPI) SCIENTIFIC_CONTACTS: DR. J. L. BURCH / DR. R. A. HOFFMAN DEPT. OF SPACE SCIENCES CODE 696 SOUTHWEST RESEARCH INST. NASA/GSFC P.O. DRAWER 28510 GREENBELT, MD 20771 SAN ANTONIO, TX 78284 PHONE: 301-286-7386 SPAN DE696::U6RAH SOURCE_CHARACTERISTICS: A. DESCRIPTION_OF_SPACECRAFT: The Dynamics Explorer 1 spacecraft was one of two satellites launched for the Dynamics Explorer program. The two spacecraft were launched together into coplanar polar orbits for the purpose of studying coupling between the magnetosphere, ionosphere, and the atmosphere. The DE-1 spacecraft was placed in a highly elliptical orbit whereas the DE-2 spacecraft had an orbit with low ellipticity. Instruments aboard the DE-1 spacecraft were: magnetometer (MAGA), plasma wave instrument (PWI), spin-scan auroral imager (SAI), retarding ion mass spectrometer (RIMS), high-altitude plasma instrument (HAPI), and hot plasma composition instrument (EICS - energetic ion composition spectrometer). B. ORBIT_INFORMATION: Because the Delta launch vehicle did not complete a full burn, the DE-1 satellite was placed in a lower than anticipated polar orbit, initially 23173 by 570 km. The orbital period was 409 min. The DE-1 and DE-2 satel- lites were launched by the same vehicle so that their orbits would be coplanar, allowing occasional two-point measurements along magnetic field lines. The DE-1 spacecraft spun at a rate of 10 rpm and the spin axis was perpendicular to the orbital plane. The apogee latitude precessed through 360 degrees in 3 years. The apogee was positioned over the north pole on September 8, 1981. C. PERFORMANCE: The DE-1 spacecraft performed well through its lifetime. The launch was on Aug. 3, 1981 and the satellite ceased science operations on Feb. 26, 1991. Power limitations forced the duty cycle to be limited such that the instruments were not on continuously. The initial average duty cycle was over 90%, but this decreased over the lifetime to about 20% at the end of life. INVESTIGATION_OBJECTIVES: The objectives of the High Altitude Plasma investigation are to contribute to the Dynamics Explorer mission goals to provide high-resolution phase-space measurements of electrons and positive ions over the energy range from 5 eV to 32 keV. These measurements, along with supporting measurements from other instruments on DE-A and DE-B, primarily address the identification of the charge carriers of Birkeland currents by the high-latitude plasma populations, the transport of plasma through the mid-altitude cusp and into the polar cap, the upward mass flow from the ionosphere into the hot plasma population of the magnetosphere, and resonant interactions between hot plasma and natural and artificially-injected plasma waves and electromagnetic waves. ( Refer to J. L. Burch et. al., Space Science Instrumentation Vol. 5, No. 4, 1981, pp. 455-456). INSTRUMENT_ATTRIBUTES: A. DESCRIPTION_OF_INSTRUMENT: The High Altitude Plasma Instrument (HAPI) consisted of an array of 5 parabolic electrostatic analyzers lying in a plane containing the spacecraft spin axis, and spanning 90 degrees in angle. Each parabolic analyzer was followed by two channel electron multipliers to measure simultaneously electrons and positive ions. The basic mode of operation provided a 32-point energy spectrum every one-half second between 5 eV and 32 keV by stepping through 32 sets of voltages on the analyzer plates on a logarithmic scale each half second. No more than 8 of the 10 sensors were used at one time; typically, 3 electron and 5 ion detectors were monitored. The detectors sampled, sampling rate, voltage levels, etc. could be changed on command allowing a large variety of modes. B. OPERATIONAL_MODE: Operation modes were normally selected to emphasize either high angular resolution or high temporal (and spatial) resolution. 1. HIGH_ANGULAR_RESOLUTION_MODE: In this mode, the programmable power supply (PPS) was stepped each time a nadir pulse was received from the spacecraft. That is, a single energy was sampled every 0.93 degree for an entire spacecraft spin period. This mode was used primarily near apogee for studies of the loss-cone effects of wave-particle interactions and for detection of ion beams produced by the upward acceleration of ionospheric ions. 2. HIGH_TEMPORAL_RESOLUTION_MODE: In this mode, multiple energy spectra were required during each spacecraft spin. Typically 24 16-point energy spectra, each covering 15 degree of spacecraft spin were measured during each spin period. An increase to 32 energy steps, covering the full energy range of the instrument, decreased the angular resolution to 30 degrees of spacecraft spin. C. MEASURED_PARAMETERS: Outputs from pulse amplifiers in the detector modules were converted into an 8-bit compressed telemetry word using a quasi-logarithmic compression scheme. A decompression algorithm is used to calculate a decimal count rate, and with appropriate geometric factors, accumulation times and detector efficiencies, various types of fluxes can be derived as a function of energy. These fluxes are described in the file FORMAT.SFD and include the calculations via software provided of the differential number flux, the differential energy flux, and the phase space density. The distribution function can be derived from the phase space density data by contouring the density in velocity space. Software is not provided for this last calculation. D. PERFORMANCE_OF_THE_INSTRUMENT: The HAPI instrument initially performed very well after the spacecraft was launched. However, no data were received after December 1, 1981 due to high voltage power failure. E. RESOLUTION: Each SATM record contains one DE-1 major telemetry frame (8 seconds) of data. The HAPI stepping power supply always provided voltages to the electrostatic analyzers at a rate of 64 steps per second. It had the capability of producing a staircase of 64 different steps to cover the energy range from 5 eV to 32 keV on a logarithmic scale. However, typically 32 (or 16) of the steps were used by skipping some of the steps, allowing two (or four) sweeps through the energy range per second. PARAMETERS: The SATM files contain: The date and time of the start of each record, the number of sensors which were operating, each sensor's ID number, the energy step rate, skip rate, start step, and stop step, orbit/attitude information, nadir pulse times, magnetic field data, counts from the sensors, and energy step numbers. ( Refer to Dynamics Explorer-1, HAPI/LAPI Data Processing Software System I. High Altitude Plasma Instrument (HAPI), CSC documentation CSC/TM-82/6132, Section 2). It should be noted that the SATM files do not contain geophysically meaningful parameters from the HAPI instrument. Such parameters, as described in (C. MEASURED PARAMETERS), are obtained via the software provided which reads the SATM files and calculates the parameters. The magnetic field parameters are only used for the calculation of the pitch angles of the detectors. DATA_SET_QUALITY: There have been few problems with data quality. There is about a 5% error in the calibration. DATA_PROCESSING_OVERVIEW: A. DATA_PROCESSING_CYCLE: The Stand Alone Telemetry (SATM) files were generated directly from DE-1 Telemetry files stored on optical disks and merged with orbit data from the DE Orbit/Attitude database. B. HISTORY: The original HAPI SATM file database was generated on the DE Sigma-9 computer. The Sigma-9 software had problems dealing with time gaps and telemetry errors, and produced fragmented files (several files per pass). Mission Analysis Files (MAFs) were also generated on the Sigma-9 and used for analysis and plotting. In 1992, the HAPI SATM database was regenerated on a microVax computer to correct these problems. Only a few of the old Sigma-9 files are still in use where new SATM files could not be generated. However these have been converted to the new SATM format. These are marked by the letter D in the SATM file name. (See NAMING_CONVENTION.) These SATM files may be incomplete. The rest of the old Sigma-9 files, as well as MAFs are no longer in use. A new, more efficient file structure was used allowing easier access and reducing file size. See the file FORMAT.SFD for information concerning the HAPI SATM files. DATA_SET_NAME: HAPI STAND-ALONE TELEMETRY FILES (SATM) DATA_USAGE: DATA_ORGANIZATION: Are described in FORMAT.SFD . TIME_SPAN_OF_THE_DATA: 20-AUG-1981 TO 01-DEC-1981 TYPE_OF_FILE_RELATIONSHIP: All the HAPI instrument data are contained in SATM files. TIME_GAPS: There are occasionally time gaps between major frames. This is due to the fact that bad major frames were not written to the SATM files. Care should be taken in checking for time gaps when analyzing the data. SOFTWARE_TO_UNPACK_THE_DATA: The utility is included in HLAPI_SOFTWARE.TAR-GZ that must be uncompressed and untarred (zcat hlapi_software.tar-gz | tar xvf -) and stored in your local directory. Instructions on how to use the software can be found in the file HOW_TO_USE_REDUCE_SATM.TXT in the HAPI directory. SOFTWARE_APPLICATION_SCOPE: This utility applies to all the data files, i.e. those that can be named (using wildcards, and "/" to denote directory levels) /HAPI/8*/*.SATM . CCSD$$MARKERMRK**002CCSD3KS00002MRK**003 LOG_VOL_COVERAGE: 1981-11-05 TO 1981-12-01 General Note: Inspecting the names of the directories that are subordinate to the HAPI directory will directly indicate the dates of the data covered in the given volume. For example, on the first side (HAPI01) one of the directories is named: 81228_81257 This means that the data covered in the directory is "from 1981, 228th day through 1981, 257th day, inclusive." The three platter-sides are named HAPI01, HAPI02, and HAPI03. The directories on the three platter-sides are: (HAPI01) (HAPI02) (HAPI03) 81228_81257 81285_81288 81309_81312 81258_81263 81289_81292 81313_81316 81264_81269 81293_81296 81317_81321 81270_81275 81297_81300 81322_81325 81276_81279 81301_81304 81326_81330 81280_81284 81305_81308 81331_81335 There are two files that list the names/time-coverages/directories of the data files (*.SATM). One of these files lists this information for the "current" platter-side, and the other file lists this for all three platter sides. The format of these two lists is the same, and is described in the file LISTFORM.SFD . TYPES_OF_DATA_FILES_INCLUDED: HAPI SATM FILES ONLY SATM_TIME_COVERAGE: 1981-11-05T01:30:51 TO 1981-12-01T12:57:37 NAMING_CONVENTION: The start day and time are encoded in the HAPI SATM filename. Each HAPI SATM filename is in the following format: 'HyrdayhhmmB.SATM' H - indicates a HAPI file ( all files in this dataset are H) yr - the last two digits of the year, i.e., 81 for 1981 day - the Julian day (Jan 1 = 001) hh - the starting hour of the file mm - the starting minute of the file B - the production version of the file. Most files in this data set are B, the few files from the Sigma-9 are D. Further information may be found in DATA_PROCESSING_OVERVIEW (above), in subsection B, "HISTORY". SATM - the extension, indicating it is a Stand Alone Telemetry file For example: H812820506B.SATM would be a HAPI SATM file which started at 5:06 on Julian day 282 in 1981. FILE_TIME_COVERAGE: See LOG_VOL_COVERAGE, above, and See NAMING_CONVENTION, above, and See file THIS_SIDE_.DATA_FILE_LIST, and See file ALL_3_SIDES.DATA_FILE_LIST. OTHER_LOG_VOL_COVERAGE: 1981-08-16 TO 1981-10-11 1981-10-12 TO 1981-11-04 CCSD$$MARKERMRK**003CCSD3RF0000300000001 REFERENCETYPE=$CCSDS2; LABEL=ATTACHED; REFERENCE="/HAPI/FORMAT.SFD"; REFERENCE="/HAPI/LISTFORM.SFD"; LABEL=CCSD3SF0000200000001; REFERENCE="/HAPI/HLAPI_SOFTWARE.TAR-GZ-*"; REFERENCE="/HAPI/HOW_TO_USE_REDUCE_SATM.TXT-*"; LABEL=NSSD3IF0018400000001; REFERENCE="/HAPI/81309_81312/*.SATM-*"; REFERENCE="/HAPI/81313_81316/*.SATM-*"; REFERENCE="/HAPI/81317_81321/*.SATM-*"; REFERENCE="/HAPI/81322_81325/*.SATM-*"; REFERENCE="/HAPI/81326_81330/*.SATM-*"; REFERENCE="/HAPI/81331_81335/*.SATM-*"; LABEL=NSSD3KF0012900000001; REFERENCE="/HAPI/THIS_SIDE.DATA_FILE_LIST-*"; REFERENCE="/HAPI/ALL_3_SIDES.DATA_FILE_LIST-*"; /* (EOF) */