CCSD3ZF0000100000001NJPL3IF0PDSX00000001 PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 1988-01-15 NOTE = "DSN Orbit Data File Software Interface Specification. Typed in from hard copy original" END_OBJECT = TEXT END x (Insert this modular document in 820-13; Rev. A) EFFECTIVE DATE: May 15, 1984 Initial Release Date: June 15, 1983 Reissue Date: January 15, 1988 Approved by: Joseph A. Wackley (430) ----------------------------- Edward J. Christensen (338) ----------------------------- G.L. Goltz (314) ----------------------------- J.E. Ekelund (314) ----------------------------- A. PURPOSE This module specifies the orbit data file (ODF) format of the radio metric data from the Deep Space Network (DSN). The content and formats of the ODF data blocks generated by the Network Operations Control Center (NOCC) Navigation Subsystem (NAV) and either transmitted by the NOCC Support Subsystem (NSS) or provided on magnetic tape are herein defined. B. REVISION AND CONTROL Revisions or changes to information herein presented may be initiated in accordance with the procedures in Section I of this document. C. GENERAL INFORMATION When the ODFs are to be transmitted, the Ground Communications Facility (GCF) is assumed to be transparent. The data shall be formatted into 1200-bit or 4800-bit data blocks and transmitted to the user via the Digital Communications Subsystem (GDC) of the GCF. The data will be stored by the NOCC NAV for transmission. Figure 1 shows the data flow from the DSN Signal Processing Center (SPC) to the Remote Mission Operations Center (RMOC) for the transmitted data and for data provided on magnetic tape. D. DATA FORMAT AND FIELDS 1. GCF Data Blocks The ODF data blocks are standard 1200-bit or 4800-bit data blocks that contain radio metric data that have been reformatted from the 820-13, TRK-2-14, TRK-2-15, or TRK-2-20 formats. Figure 2 shows the ODF 1200-bit block format and Figure 3 shows the ODF 4800-bit block format. The first 120 bits of the block form the block header and provide information common to all data in the block. The Block Information Field (BIF) consisting of 1032 bits for a 1200-bit block, contains three packets (each consisting of nine 32-bit words) described in Tables 1 through 7. The BIF for the 4800-bit block consists of 4632 bits and contains 16 packets of data. The last 48 bits of the data block contain the GCF error detection and correction data, the Error Status Code (ESC) and the Error Polynomial Code (EPC). The ODF blocks will be ordered by block header time and date. Detailed descriptions of the header, BIF, and block ending are provided in the following paragraphs: WORD 1 THRU WORD 8, BIT 8 Standard DSN Block Header as described in module OPS-6-8 of this document, with the following code assignments: UDT Code = 025 (octal; or 15, hexadecimal) DDT Code = 024 (octal; or 14, hexadecimal) WORD 8, BITS 9 THRU 16 Set to zeros WORD 9 THRU WORD 72/WORD 297 BIF - ODF data with the following constraints: (1) Each complete ODF will span several blocks. (2) A complete ODF will consist of the following data presented in order of transmission: a) File Label group - one per ODF (Tables 1a and 1b) b) Identifier group - one per ODF (Tables 2a and 2b) c) Orbit Data group - multiple records, time ordered (Tables 3a and 3b) d) Ramp groups - one group for each DSS, multiple records, time ordered (Tables 4a and 4b) e) Clock Offsets group - multiple records, time ordered (Tables 5a and 5b) f) Data Summary group - multiple records, ordered by station, band, and data type (Tables 6a and 6b) g) End-of-File group - one per ODF (Table 7) (3) Each ODF consists of the radio metric data for one spacecraft, zero or more quasars, and one or more stations. (4) Character data are 8-bit ASCII-equivalent integer values (5) Times, except as noted, are given as seconds past zero hours UTC, of January 1, 1950. (6) For 1200-bit blocks, Words 63 through 72 will always contain filler (repetitive 10002). For 4800-bit blocks, Word 297 will always contain filler. Unused portions of any BIF will contain filler. (7) The ODF data words are 32 bits in length. (8) The 5th data word of an ODF packet/record is always zero (0) for a group header record, and is always non- zero for a data record. WORD 73 THRU WORD 75/WORD 298 THRU WORD 300 Standard DSN block ending as described in module OPS-6-8 of this document. 2. Magnetic Tape Interface The ODF data are provided on unlabeled, 9-track, 1600-b/in. magnetic tapes. Each ODF block (or physical record) consists of 2016 32-bit words, for a total length of 64,512 bits. Each block contains 224 9-word (288-bit) logical records. These records are described in Tables TRK-2-18-1 through -7. Table 1a. ODF File Label Group Header Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Primary Key = 101 | | 2 | 33- 64 | 32 | 2 | Secondary Key = 0 | | 3 | 65- 96 | 32 | 3 | Logical Record Length (in packets) = 1 | | 4 | 97-128 | 32 | 4 | Group Start Packet Number (=0) | | 5-9 | 129-288 | 5*32 | 5-9 | 0 | |============================================================================| Table 1b. ODF File Label Group Data Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 8 | 8 | 1 | 1st ASCII "Character" of System ID | | 2 | 9- 16 | 8 | | 2nd ASCII "Character" of System ID | | 3 | 17- 24 | 8 | | 3rd ASCII "Character" of System ID | | 4 | 25- 32 | 8 | | 4th ASCII "Character" of System ID | | 5 | 33- 40 | 8 | 2 | 5th ASCII "Character" of System ID | | 6 | 41- 48 | 8 | | 6th ASCII "Character" of System ID | | 7 | 49- 56 | 8 | | 7th ASCII "Character" of System ID | | 8 | 57- 64 | 8 | | 8th ASCII "Character" of System ID | | 9 | 65- 72 | 8 | 3 | 1st ASCII "Character" of System ID | | 10 | 73- 80 | 8 | | 2nd ASCII "Character" of System ID | | 11 | 81- 88 | 8 | | 3rd ASCII "Character" of System ID | | 12 | 89- 96 | 8 | | 4th ASCII "Character" of System ID | | 13 | 96-104 | 8 | 4 | 5th ASCII "Character" of System ID | | 14 | 105-112 | 8 | | 6th ASCII "Character" of System ID | | 15 | 113-120 | 8 | | 7th ASCII "Character" of System ID | | 16 | 121-128 | 8 | | 8th ASCII "Character" of System ID | | 17 | 129-160 | 32 | 5 | Spacecraft ID Number | | 18 | 161-192 | 32 | 6 | File Creation Time (YYMMDD) | | 19 | 193-224 | 32 | 7 | File Creation Time (hhmmss) | | 20 | 225-256 | 32 | 8 | 0 (Spare) | | 21 | 256-288 | 32 | 9 | 0 (Spare) | |============================================================================| Table 2a. ODF Identifier Group Header Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Primary Key = 107 | | 2 | 33- 64 | 32 | 2 | Secondary Key = 0 | | 3 | 65- 96 | 32 | 3 | Logical Record Length (in packets) = 1 | | 4 | 97-128 | 32 | 4 | Group Start Packet Number (= 2) | | 5 | 129-288 | 5*32 | 5-9 | 0 | |============================================================================| Table 2b. ODF Identifier Group Data Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1- 8 | 1- 64 | 8*8 | 1-2 | "TIMETAG" - 8 ASCII "Characters" | | 9-16 | 65-128 | 8*8 | 3-4 | "OBSRVBL" - 8 ASCII "Characters" | | 17-28 | 129-224 | 12*8 | 5-7 | "OD-SAMPL-ID" - 12 ASCII "Characters" | | 29-36 | 225-288 | 8*8 | 8-9 | "FRQ RSD" - 8 ASCII "Characters" | |============================================================================| Table 3a. ODF Orbit Data Group Header Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Primary Key = 109 | | 2 | 33- 64 | 32 | 2 | Secondary Key = 0 | | 3 | 65- 96 | 32 | 3 | Logical Record Length (in packets) = 1 | | 4 | 97-128 | 32 | 4 | Group Start Packet Number (= 4) | | 5-9 | 129-288 | 5*32 | 5-9 | 0 | |============================================================================| Table 3b. ODF Orbit Data Group Header Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Record Time Tag, integer part | | 2 | 33- 64 | 32 | 2 | Record Time Tag, fractional part | | | | | | (10^-9) | | 3 | 65- 96 | 32 | 3 | Observable, integer part (two's | | | | | | complement)*~ | | 4 | 97-128 | 32 | 4 | Observable, fractional part (two's | | | | | | complement, 10^-9)#~ | | 5 | 129-131 | 3 | 5 | Format ID (= 1) | | 6 | 132-138 | 7 | | Receiving Station ID Number, if | | | | | | tracking data | | | | | | 1st Receiving Station ID Number, | | | | | | if VLBI data | | 7 | 139-145 | 2 | | Transmitting Station ID Number | | 8 | 146-147 | 2 | | Network ID Number for Receiving | | | | | | Station: 1 = DSN | | 9 | 148-149 | 2 | | Downlink Band ID: | | | | | | 0 = Not applicable | | | | | | 1 = S-band | | | | | | 2 = X-band | | | | | | 3 = L-band | | 10 | 150-155 | 6 | | Data Type ID Number: | | | | | | 01 = Narrowband spacecraft VLBI, mode | | | | | | 02 = Narrowband spacecraft VLBI, | | | | | | phase mode | | | | | | 03 = Narrowband quasar VLBI, | | | | | | Doppler mode | | | | | | 04 = Narrowband quasar VLBI, phase mode| | | | | | 05 = Wideband spacecraft VLBI | | | | | | 06 = Wideband Quasar VLBI | | | | | | 07 = Narrowband delta-DOR | | | | | | 08 = Wideband delta-DOR | | | | | | 11 = One-way Doppler | | | | | | 12 = Two-way Doppler | | | | | | 13 = Three-way Doppler | | | | | | 14 = Three-way coherent Doppler | | | | | | 26 = DRVID using PRA ranging | | | | | | 27 = DRVID using SRA ranging | | | | | | 28 = DRVID using MU2 ranging | | | | | | 36 = Planetary operational discrete | | | | | | spectrum range (PRA) | | | | | | 37 = Planetary operational discrete | | | | | | spectrum range (SRA) | | | | | | 38 = Discrete spectrum range (MU2) | | | | | | 4l = Goddard nanosecond range (GSTDN) | | | | | | 51 = Azimuth | | | | | | 52 = Elevation | | | | | | 53 = Hour angle | | | | | | 54 = Declination | | | | | | 55 = X angle (where +X is East) | | | | | | 56 = Y angle (where +X is East) | | | | | | 57 = X angle (where +X is South) | | | | | | 58 = Y angle (where +X is South) | | 11 | 156-159 | 4 | | Highest Ranging Component, if | | | | | | range data | | | | | | Channel ID Number, if n/b VLBI data | | | | | | Mode ID Number, if w/b VLBI data | | | | | | 0, otherwise | | 12 | 160 | 1 | | 0 if VLBI quasar data; Spacecraft ID | | | 161-167 | 7 | 6 | Number otherwise | | 13 | 168-177 | 10 | | Pass ID Number, if tracking data | | | | | | Quasar ID Number, if VLBI quasar data | | | | | | 0, otherwise | | 14 | 178-179 | 2 | | Split Pass ID Number, if tracking data | | | | | | Modulus indicator, if wideband VLBI data | | | | | | 0, otherwise | | 15 | 180-186 | 7 | | 2nd Receiving Station ID Number, | | | | | | if VLBI data | | | | | | 4-bit spare (0), 2-bit Exciter band ID | | | | | | (see item 16 for codes), and 1-bit | | | | | | Receiver/Exciter Independent Flag | | | | | | (0 = no, 1 = yes) otherwise | | 16 | 187-188 | 2 | | Uplink Band ID: | | | | | | 0 = Not applicable | | | | | | 1 = S-band | | | | | | 2 = X-band | | | | | | 3 = C-band | | 17 | 189-192 | 4 | | Power/Noise Ratio, if range or DRVID | | | 193-199 | 7 | 7 | data (10^-1, two's complement) | | | | | | Modulus integer part, if wideband VLBI | | | | | | data | | | | | | 0, otherwise | | 18 | 200 | 1 | | Data Validity (0 = good, 1 = bad) | | 19 | 201-224 | 24 | | Compression Time (hundredths of | | | | | | seconds), if Doppler or narrow-band | | | | | | VLBI data | | | | | | 18-bit Downlink Ranging Transmitter | | | | | | Coder In-Phase offset from Sample | | | | | | Timetag (seconds), and 6-bit Lowest | | | | | | Ranging Component, if range data | | | | | | Modulus fractional part (10^-7), | | | | | | if wideband VLBI data | | | | | | Integer seconds of range, if | | | | | | Goddard nanosecond range& | | | | | | 0, otherwise | | 20 | 225-256 | 32 | 8 | Frequency, part 1 (tens of Hz)% | | 21 | 257-264 | 8 | 9 | Frequency, part 2 (tenths of Hz)% | | 22 | 265-288 | 24 | | Residual (10-3), two' complement), | | | | | | if Doppler data | | | | | | 18-bit Uplink Ranging Transmitter | | | | | | Coder In-Phase offset from Sample | | | | | | Timetag (seconds), and 6-bit spare | | | | | | (0), if range data | | | | | | 0 (spare), otherwise | |============================================================================| * For Goddard nanosecond range (DT 41), this item will contain the integer nanoseconds of range. # For Goddard nanosecond range (DT 41), this item will contain the fractional nanoseconds of range. ~ See Appendix A for description of the Doppler and Range observables. & Item 19 must be combined with items 3 and 4 to arrive at the observable range value. % Transponder frequency, if 1-way Doppler; receiver frequency, if ramped and not 1-way; transmitter frequency, otherwise. Table 4a. ODF Ramp Groups Header Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Primary Key = 2030 | | 2 | 33- 64 | 32 | 2 | Secondary Key = Station ID Number | | 3 | 65- 96 | 32 | 3 | Logical Record Length (in packets) = 1 | | 4 | 97-128 | 32 | 4 | Group Start Packet Number | | 5 | 129-288 | 5*32 | 5-9 | 0 | |============================================================================| Table 4b. ODF Ramp Groups Data Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Ramp Start Time, integer part | | 2 | 33- 64 | 32 | 2 | Ramp Start Time, fractional part (10^-9) | | 3 | 65- 96 | 32 | 3 | Ramp Rate, integer part(two's complement)| | 4 | 97-128 | 32 | 4 | Ramp Rate, fractional part, (two's | | | | | | complement, 10^-9) | | 5 | 129-160 | 32 | 5 | Receiving/Transmitting Station ID Number | | 6 | 161-192 | 32 | 6 | Ramp Start Frequency, integer part | | 7 | 193-224 | 32 | 7 | Ramp Start Frequency, fractional part | | | | | | (10^-9) | | 8 | 225-256 | 32 | 8 | Ramp End Time, integer part | | 9 | 257-288 | 32 | 9 | Ramp End Time, fractional part (10^-9) | |============================================================================| Table 5a. ODF Clock Offsets Group Header Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Primary Key = 2040 | | 2 | 33- 64 | 32 | 2 | Secondary Key = 0 | | 3 | 65- 96 | 32 | 3 | Logical Record Length (in packets) = 1 | | 4 | 97-128 | 32 | 4 | Group Start Packet Number | | 5 | 129-288 | 5*32 | 5-9 | 0 | |============================================================================| Table 5b. ODF Clock Offsets Group Data Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Ramp Start Time, integer part | | 2 | 33- 64 | 32 | 2 | Ramp Start Time, fractional part (10^-9) | | 3 | 65- 96 | 32 | 3 | Clock Offset, integer part (two's | | | | | | complement) | | 4 | 97-128 | 32 | 4 | Clock Offset, fractional part, (two's | | | | | | complement, 10^-9) | | 5 | 129-160 | 32 | 5 | Primary Station ID Number | | 6 | 161-192 | 32 | 6 | Secondary Station ID Number | | 7 | 193-224 | 32 | 7 | 0 (spare) | | 8 | 225-256 | 32 | 8 | 0 (reserved for End Time, integer part) | | 9 | 257-288 | 32 | 9 | 0 (reserved for End Time,fractional part)| |============================================================================| Table 6a. ODF Data Summary Group Header Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Primary Key = 105 | | 2 | 33- 64 | 32 | 2 | Secondary Key = 0 | | 3 | 65- 96 | 32 | 3 | Logical Record Length (in packets) = 1 | | 4 | 97-128 | 32 | 4 | Group Start Packet Number | | 5 | 129-288 | 5*32 | 5-9 | 0 | |============================================================================| Table 6b. ODF Data Summary Group Data Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | First Sample Time, integer part | | 2 | 33- 64 | 32 | 2 | First Sample Time, fractional part(10^-9)| | 3 | 65- 96 | 32 | 3 | Station ID Number | | 4 | 97-128 | 32 | 4 | Network ID Number | | 5 | 129-160 | 32 | 5 | Band ID Number | | 6 | 161-192 | 32 | 6 | Data Type ID Number | | 7 | 193-224 | 32 | 7 | Number of Samples (in ODF) | | 8 | 225-256 | 32 | 8 | Last Sample Time, integer part | | 9 | 257-288 | 32 | 9 | Last Sample Time, fractional part (10^-9)| |============================================================================| Table 7. ODF End-of-File Group Format |============================================================================| | Item | Bit | Length | Data | Description | |Number | Number | (bits) | Word | | |-------+---------+--------+------+------------------------------------------| | 1 | 1- 32 | 32 | 1 | Primary Key = -1 | | 2 | 33- 64 | 32 | 2 | Secondary Key = 0 | | 3 | 65- 96 | 32 | 3 | Logical Record Length (in packets) = 0 | | 4 | 97-128 | 32 | 4 | Group Start Packet Number | | 5 | 129-288 | 5*32 | 5-9 | 0 | |============================================================================| ------------------------------------------------------------------------------ ---------- --------- ---------- | REMOTE | | | | DSCC | | MISSION |<---------| GCF/ |<--------------| TRACKING | |OPERATIONS| TRK-2-18 | NASCOM | TRK-2-15/2/20 | SUB- | | CENTER | | | | SYSTEMS | ---------- --------- ---------- ^ | TRK-2-18 | | TRK-2-15/2-20 ----------- | | ----------- | NETWORK | | | | DATA | | COMM |----------- ---------------->| RECORDS | | EQUIPMENT | | SUBSYSTEM | | (NCE) | | (GDR) | ----------- ----------- ^ | | | | v | ----- | / \ | TRK-2-18 IDR-12-1 / IDR \ | \ tape / | \ / hand | ----- delivery | | / \ | . - - - \ . | v \ ---------- --------- ------------ ----- | NOCC | | | | NOCC | / \ | SUPPORT |<---------| ODF |<--------------| NAVIGATION |-->/ ODF \ |SUBSYSTEM | | | | SUBSYSTEM | \ tape / | (NSS) | | | | (NAV) | \ / ---------- --------- ------------ ----- ^ | | . | TRK-2-18 | ----- . / \ | / ODF \ < - - - - - - - - - - - - - - - - - - - - - - - - - - - - \ tape / \ / ----- Figure 1. Data Flow for Orbit Data File Interface ------------------------------------------------------------------------------ |-----------------------------------------------| WORD |01|02|03|04|05|06|07|08|09|10|11|12|13|14|15|16| |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 1 |SYNC CODE | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 2 |SYNC CODE |SOURCE CODE | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 3 |DESTINATION CODE |BLOCK FORMAT CODE | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 4 |GDD |UDT CODE |DDT CODE | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 5 |DDT|SPACECRAFT CODE |TIME | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 6 |TIME | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 7 |CCT |DAY OF YEAR | BLK SER NO| |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 8 |BLOCK SERIAL NUMBER | 0 0 0 0 0 0 0 0| |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 9 |FIRST PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 10 | ^ | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| | | | / / / / / / | | | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| 25 | v | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 26 |FIRST PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 27 |SECOND PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 28 | ^ | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| | | | / / / / / / | | | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| 43 | v | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 44 |SECOND PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 45 |THIRD PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 46 | ^ | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| | | | / / / / / / | | | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| 61 | v | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 62 |THIRD PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 63 |FILLER (REPETITIVE BINARY 1000) | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 64 | ^ | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| | | | / / / / / / | | | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| 71 | v | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 72 |FILLER (REPETITIVE BINARY 1000) | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 73 |ERROR CORRECTION | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 74 |ERROR CORRECTION |ESC |ERROR POLY CODE | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 75 |ERROR POLYNOMIAL CODE | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| |01|02|03|04|05|06|07|08|09|10|11|12|13|14|15|16| |-----------------------------------------------| Figure 2. Orbit Data File 1200-Bit Data Block Format ------------------------------------------------------------------------------ |-----------------------------------------------| WORD |01|02|03|04|05|06|07|08|09|10|11|12|13|14|15|16| |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 1 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 2 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 3 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 4 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 5 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 6 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 7 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 8 |GCF | 0 0 0 0 0 0 0 0| |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 9 |1st PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 10 | ^ | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| | | | / / / / / / | | | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| 25 | v | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 26 |1st PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 27 |2nd PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 28 | ^ | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| | | | / / / / / / | | | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| 43 | v | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 44 |2nd PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 45 |3rd PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 46 | ^ | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| | | | / / / / / / | | | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| 61 | v | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 62 |3rd PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 63 |4th PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 64 | ^ | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| | | | / / / / / / | | | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| 277 | v | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 278 |15th PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 279 |16th PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 280 | ^ | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| | | | / / / / / / | | | |--+--+--+--+--|--+--+--+--+--+--+--+--+--+--+--| 295 | v | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 296 |16th PACKET | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 297 |FILLER (REPETITIVE BINARY 1000) | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 298 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 299 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| 300 |GCF | |--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| |01|02|03|04|05|06|07|08|09|10|11|12|13|14|15|16| |-----------------------------------------------| Figure 3. Orbit Data File 4800-Bit Data Block Format ------------------------------------------------------------------------------ APPENDIX A DOPPLER AND RANGE OBSERVABLES Doppler and range observables, rather than the actual measurements made at the Deep Space Stations, are provided in the ODF Orbit Data Group (see Table 3b, items 3 and 4). The Doppler observable (in Hertz) is computed according to the following equation. The time tag is at the mid-point of the compression interval, ti to tj. Observable = (B/|B|) x [(Nj - Ni)/(tj - ti) - |Fb + B|] x K where: B = Bias frequency of measured Doppler Ni = Doppler count at time ti Nj = Doppler count at time tj ti = start time of interval tj = end time of interval K = 1 for S-band receivers (Table 3b, Item 9) 11/3 for X-band receivers 1 for L-band receivers Fb = (240/221) x (96 x Fr) - FSC + R3 for 1-way Doppler = (X1/X2) x (X3 x Fr + X4) - (T1/T2) x (T3 x Ft + T4) for all other Doppler where: Fr = Receiver (VCO) frequency at time tr FSC = Spacecraft (beacon) frequency Ft = Transmitter frequency at time tr-RTLT R3 = 0 for S-band receivers = 0 for X-band receivers = -620,000,000 for L-band receivers T1 = 240 for S-band transmitters (Table 3b, Item 16) = 240 for X-band transmitters = 228 for C-band transmitters T2 = 221 for S-band transmitters = 749 for X-band transmitters = 681 for C-band transmitters T3 = 96 for S-band transmitters = 32 for X-band transmitters = 232 for C-band transmitters T4 = 0 for S-band transmitters = 6,500,000,000 for X-band transmitters = 0 for C-band transmitters X1 to X4 have the same values at T1 to T4 but are dependent on the exciter band (Table 3b, Item 15, 2nd subitem). For Doppler data, the residual is computed as the average of the measured residuals at the end points of the compression interval (so that its time tag is the same as that of the Doppler observable): Residual = (Rj + Ri)/2 For range data, the observable is computed as follows: Observable = R - C + Z - S where: R = range C = Station delay calibration Z = Z correction S = Spacecraft delay