PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM RECORD_BYTES = 87 FILE_RECORDS = 826 ^SPREADSHEET = "SDCPOWER.CSV" DATA_SET_ID = "NH-P-SDC-3-PLUTO-V3.0" INSTRUMENT_HOST_NAME = "NEW HORIZONS" INSTRUMENT_HOST_ID = "NH" INSTRUMENT_NAME = "STUDENT DUST COUNTER" INSTRUMENT_ID = "SDC" PRODUCT_NAME = "SDCPOWER" PRODUCT_CREATION_TIME = 2017-04-30T00:00:00 START_TIME = 2006-01-19T18:08:00.000 STOP_TIME = 2017-09-12T11:00:05.673 DESCRIPTION = " The Comma-Separated Values (CSV) SPREADSHEET document provides a summary of times of on and off commands sent to the Student Dust Counter (SDC) instrument on-board the New Horizons (NH) spacecraft. The SPREADSHEET file comprises rows, each with comma delimiters between fields, quotes (ASCII code 34 decimal) surrounding character fields, and row lines terminated by a carriage return and a line feed (ASCII codes 13 and 10 decimal, respectively). The purpose of this document is to provide PDS users with a rough guide to assess when the SDC instrument was taking data. Refer to SDC.CAT in the CATALOG/ directory of this data set for information about the SDC instrument. Each row of the SPREADSHEET contains four fields, representing a command that turns the SDC either on or off. This file does not account for power activities that turn individual dust detector channels on and off due either to explicit per-channel commanding or to autonomy rules. Refer to the SDC ON/OFF tables for more detail. The four fields comprise two times, one indication whether the row signals an ON command or and OFF command, and one provenance string providing the source of the information in the row. The SPREADSHEET was generated using two parallel sources for the commands, Spacecraft Sequence Files (SSFs) and CoMmanD (CMD) files. Both types of files come from ground-based simulations of spacecraft operation responding to anticipated command sequences. As such, many of the commands appear twice. Because of differences in the fidelity of the simulations, the times of those events may not match up exactly, but will agree to within a few seconds of each other; this is normal behavior and not an error. In addition, both simulations will also be within a few seconds of the actual execution on the spacecraft. The point to take away is that the SPREADSHEET is a rough, not an exact, model of spacecraft operation, and this is intentional. The first row of the table is a default OFF state at a zero Mission Elapsed Time (MET); it does not come from any SSF for CMD source but is present to initialize the modeled state of the SDC. " OBJECT = SPREADSHEET ROWS = 826 ROW_BYTES = 88 /* 10 + ,23 + ,"3" + ,"43" + CRLF */ FIELDS = 4 FIELD_DELIMITER = "COMMA" OBJECT = FIELD NAME = "MET" FIELD_NUMBER = 1 BYTES = 10 FORMAT = "I10" DATA_TYPE = "ASCII_INTEGER" UNIT = "SECOND" DESCRIPTION = "This field is the approximate Mission Elapsed Time (MET) of the command represented by the row. It is the number of spacecraft seconds counted by the spacecraft clock since approximately 2006-01-19T18:08:00 UTC. " END_OBJECT = FIELD OBJECT = FIELD NAME = "TIME" FIELD_NUMBER = 2 BYTES = 23 FORMAT = "A20" DATA_TYPE = "TIME" DESCRIPTION = "This field is the approximate UTC of the command represented by the row. " END_OBJECT = FIELD OBJECT = FIELD NAME = "ON OFF STATE" FIELD_NUMBER = 3 BYTES = 3 FORMAT = "A3" DATA_TYPE = "CHARACTER" DESCRIPTION = "This field indicates whether the command represented by the row turned the SDC on or off. Its value will be either ON or OFF. " END_OBJECT = FIELD OBJECT = FIELD NAME = "PROVENANCE" FIELD_NUMBER = 4 BYTES = 43 FORMAT = "A43" DATA_TYPE = "CHARACTER" DESCRIPTION = "This field indicates the source of the information on the row. It has three sub- fields, delimited by colons (ASCII code 58 decimal. This field is intended only for debugging of the creation of the SPREADSHEET file and for no other purpose, and it can safely be ignored by PDS users. The second sub-field is the offset from the first line in the source file to the line with this command. The third sub-field has the command, plus any command parameters, as sub-sub-fields; the third field is usually contained within square brackets (ASCII codes 91 and 93, decimal), and multiple sub-sub-fields are delimited by commas. The filename (first sub-field) will typically be of the form YYDOY.ssf or YYDOY.cmd, where YY is the number of the year modulo 100, and DOY is the number of the day of year of the approximate start of the SSF or CMD file. The line number (second sub-field) is never expected to exceed 99,999. Possible values for the third sub-sub-field are the following: None [SDC_LVPS_POWER,CDBOTH,OFF] [SDC_LVPS_POWER,CDBOTH,ON] [SDC_PWR_OFF] For the first line in the SPREADSHEET, the three sub-fields will be 00000.cmd, -1 and None; these are placeholders to match the format, but are otherwise meaningless. " END_OBJECT = FIELD END_OBJECT = SPREADSHEET END