OBJECT = COLUMN NAME = SCLK_SECOND DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 4 DESCRIPTION = "Spacecraft clock counter of onboard seconds, since the epoch of May 3, 2003 (123) at which the first pulse of a sounding set is transmitted. This value is typically referred to as the frame time. Since 160 pulses are transmitted during the collection of a single frame's worth of measurements, this value is almost always constant for each set of 160 records." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCLK_PARTITION DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 5 BYTES = 2 DESCRIPTION = "Spacecraft clock counter partition of onboard counter roll-over/reset. Zero or one indicates the counter is in the first partition. See the NAIF Spice documentation." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCLK_FINE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 7 BYTES = 2 DESCRIPTION = "Spacecraft clock counter of onboard fractions of a second with one fraction being 1/65536. This is the sub-seconds portion of the frame time and is thus also constant for 160 records" END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCET_DAYS DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 9 BYTES = 4 DESCRIPTION = "Spacecraft event time in days since 1958-001T00:00:00Z. This is the historical epoch used since the launch of the first U.S. satellite Explorer I with Dr. James Van Allen's (University of Iowa) cosmic-ray instrument as the principal element of the payload, resulting in the discovery of the Van Allen Radiation Belts." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCET_MSEC DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 13 BYTES = 4 DESCRIPTION = "Spacecraft event time in milliseconds of day. SCET_DAYS and SCET_MSEC are provided to accurately time tag the data in UTC without the need for calls to the spice kernel." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCET_STRING DATA_TYPE = CHARACTER START_BYTE = 25 BYTES = 24 DESCRIPTION = "Spacecraft event time of the first transmit pulse in a set. Pulse sets typically consist of 160 frequencies which are triggered sequentially with 7.8571 milliseconds between pulses." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PROCESS_ID DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 49 BYTES = 1 DESCRIPTION = "The seven bits from the 20,3 telemetry packet header which determine the instrument process id. 0x4D (77d) = Subsurface Sounder (SS1 to SS4) 0x4E (78d) = Active Ionospheric Sounder (AIS) 0x4F (79d) = Calibration (CAL) 0x50 (80d) = Receive Only (RCV)" END_OBJECT = COLUMN OBJECT = COLUMN NAME = INSTRUMENT_MODE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 50 BYTES = 1 DESCRIPTION = "The bits from the 20,3 telemetry packet header used to determine the instrument data type and mode selection." OBJECT = BIT_COLUMN NAME = DATA_TYPE BIT_DATA_TYPE = MSB_UNSIGNED_INTEGER START_BIT = 1 BITS = 4 DESCRIPTION = " 0001 = AIS, Calibration, or Receive Only 0000 = SS1-SS5 Individual Echoes 0010 = SS1-SS5 Acquisition 0011 = SS1-SS5 Tracking " END_OBJECT = BIT_COLUMN OBJECT = BIT_COLUMN NAME = MODE_SELECTION BIT_DATA_TYPE = MSB_UNSIGNED_INTEGER START_BIT = 5 BITS = 4 DESCRIPTION = " 0101 = Calibration 0110 = Receive Only 0111 = Active Ionospheric Sounder 1000 = Subsurface Sounder 1 1001 = Subsurface Sounder 2 1010 = Subsurface Sounder 3 1011 = Subsurface Sounder 4 1100 = Subsurface Sounder 5 " END_OBJECT = BIT_COLUMN END_OBJECT = COLUMN OBJECT = COLUMN NAME = TRANSMIT_POWER DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 60 BYTES = 1 DESCRIPTION = "The transmit power level, expressed as the power supply regulation voltage for the final power amplifier output. 0x00 (0d) = minimum transmit power 2.5V 0x0F (15d) = maximum transmit power 40.0V " END_OBJECT = COLUMN OBJECT = COLUMN NAME = FREQUENCY_TABLE_NUMBER DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 61 BYTES = 1 DESCRIPTION = "The Active Ionospheric Sounder may select one of sixteen frequency tables to use during transmit. Each table has 160 frequencies that are transmitted during an AIS capture. Table 0 is the default table" END_OBJECT = COLUMN OBJECT = COLUMN NAME = FREQUENCY_NUMBER DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 62 BYTES = 1 DESCRIPTION = "The frequency number from the table, ranging from 0 to 159." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BAND_NUMBER DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 63 BYTES = 1 DESCRIPTION = "The band that was selected to receive the echo. 0 = band 0 3 = band 3 1 = band 1 4 = band 4 2 = band 2" END_OBJECT = COLUMN OBJECT = COLUMN NAME = RECEIVER_ATTENUATION DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 64 BYTES = 1 DESCRIPTION = "The receiver attenuation for band selected measured in dB." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FREQUENCY DATA_TYPE = IEEE_REAL START_BYTE = 77 BYTES = 4 UNIT = HZ DESCRIPTION = "The frequency of the transmit pulse" END_OBJECT = COLUMN OBJECT = COLUMN NAME = SPECTRAL_DENSITY DATA_TYPE = IEEE_REAL START_BYTE = 81 BYTES = 320 ITEMS = 80 ITEM_BYTES = 4 UNIT = "VOLT**2/M**2/HZ" DESCRIPTION = "A series of calibrated spectral densities from a single transmit pulse. The time offset of the first spectral density from transmit pulse initiation is 253.9286 microseconds. Each successive spectral density value was taken 91.4286 seconds after the initial value. A table of time delays may be found in the AISDS.CAT CATALOG file." END_OBJECT = COLUMN