NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Ames Research Center Moffett Field, California PIONEER VENUS PROJECT SPECIFICATION PC-456.O4 PIONEER VENUS: DATA USER REQUIREMENTS FOR SUPPLEMENTARY EXPERIMENTER DATA RECORDS May 15, 1976 l. SCOPE This specification defines the requirements of each of the Pioneer Venus data users for the Supplementary Experimenter Data Records (SEDR). 2. APPLICABLE DOCUMENTS 2.1 NASA/ARC SPECIFICATIONS PC-456.OO, Pioneer Venus: Data Records Processing System (DRPS) Description PC-456.O1, Pioneer Venus: Input and Output Tape Description PC-456.O2, Pioneer Venus: Data Records Processing System (DRPS) Detailed Processing Requirements PC-456.O3, Pioneer Venus: Data User Requirements for Experimenter Data Records PC-454.OO, Pioneer Venus: On-Line Ground Data System Software Specification PC-455.OO, Pioneer Venus: Off-Line Telemetry Data Processing Specification -1- Section No. 3.0 Doc. No. YL-430.U4 Orig. Issue Date 7/20/77 Revision No. 3 Revision 3. REQUIREMENTS 3.1 GENERAL REQUIREMENTS The general requirements and content for the Supplementary Experimenter Data Records have been covered in PC-456.O1 Pioneer Venus: Input and Output Tape Requirements. 3.2 SPECIFIC REQUIREMENTS The SEDR formats for all data users shall conform to the specification given below. In the case of the Orbiter Spacecraft, the SEDR shall be generated periodically from launch through mission completion. The Multiprobe Spacecraft SEDR shall be generated periodically from launch up until probe separation. A predicted model trajectory shall be generated for each of the probes after separation, from planet entry to impact in a format TBS. Details on the use of the various tables defined in the SEDR format and the QLSEDR format are described in Section 6.3 of this specification. Coordinate System diagrams in the trajectory portion of the format are in Figures 3.2 Sheets 1 through 8. 3.2.1 Production SEDR. The SEDRs— for both spacecraft shall contain measured or true trajectory data as shown in Figure 3.2.1 sheets 1 through 1O. These data shall be in IBM 360 Double Precision Floating Point formats. 3.2.2 Quick Look SEDR (QLSEDR). The best available data at the time the Quick Look SEDRs are being prepared is predicted trajectory data and will not contain the resolution that the production SEDRs will contain. The Logistics file shall be identical to that described above. The data file shall contain only 24 of the variables that are in the normal production SEDR. Since the variables are predicted, these selected variables shall be in IBM 360 Single Precision Floating Point formats. The format and variables which shall be carried in the QLSEDR are shown in Figure 3.2.2 sheets 1 through 7. 3.3 SEDR TAPE DELIVERY SEDR tapes shall be sent to each addressee shown in Figure 3.4 of Specification PC-456.O3. Section No. 6.3.1.2.1 Doc. No. PC-456.O4 Orig. Issue Date 7/20/77 Revision No. 3 Revision 6.3.1.2.1 Measured SRR Times. For some SRR pulses, one of the telemetered ATTM measurements will contain the time interval between the SRR pulse and the beginning of the major telemetry frame which immediately follows. For these SRR pulses, the time of the SRR pulse is calculated by: TSRR = TMAJ - (telemetered time interval) TMAJ is the Spacecraft Universal Time (SCUT) of the beginning of the major telemetry frame. 6.3.1.2.2 Estimated SRR Times. For about half of the SRR pulses, no time interval measurement will be made. For these pulses, the time of the SRR pulse is estimated by: TSSR(est) = TSRR (last measured) + (n) (spin period) TSRR (last measured) is the SCUT of the last SRR pulse for which a measured time interval was telemetered. Spin period is the spacecraft spin period from Table 3. n is the integer number of spin periods which have elapsed since the last measured SRR pulse. 6.3.1.3 Smoothed Roll Reference Times (Fs). An Fs signal follows each SRR pulse. The time of the Fs signal is calculated by: TFs = TSRR + delta delta is the time delay from SRR to Fs from Table 3. 6.3.1.4 Roll Index Pulse Times (RIP). A RIP pulse follows each Fs signal. The time of the RIP pulse is calculated by: TRIP = TFS + (RIP time delay) (RIP time delay) is the current value of the time from Fs to RIP as determined from the telemetered measurement ARIPAD. (RIP time delay) = (decimal value of ARIPAD) (Spin Period)/1024 Spin period is the spacecraft spin period from Table 3. Section No. 6.3.1.5 Doc. No. PC-456.04 Orig. Issue Date 7/20/77 Revision No. 3 Revision 6.3.1.5 Ram Pulse Times (RAM). A RAM pulse follows each RIP pulse. The time of the RAM pulse is calculated by: TRAM = TRIP + (RAM time delay) (RAM time delay) is the value of the RAM time delay at the RIP time. The RAM time delay at the time of the beginning of each major telemetry frame is calculated from the telemetered measurement AVPDRD by: RAM time delay= (decimal value of AVPDRD) x (spin period)/4096 The RAM time delay at the RIP time is interpolated to the RIP time from the telemetered measurements. (spin period) is the spacecraft spin period from Table 3. 6.3.1.6 NADIR Pulse Times (NADIR). A NADIR pulse follows each RIP pulse. The time of the NADIR pulse is calculated by: TNADIR = TRIP + (NADIR time delay) (NADIR time delay) is the value of the NADIR time delay at the RIP time. The NADIR time delay at the time of the beginning of each major telemetry frame is calculated from the telemetered measurement AVPDND by: NADIR time delay = (decimal value at AVPDND) x (spin period)/4096 (spin period if the spacecraft spin period from Table 3). The NADIR time delay at the RIP time is interpolated to the RIP time from the telemetered measurements. Section No. 6.3.2 Doc. No. PC-456.04 Orig. Issue Date 7/20/77 Revision No. 3 Revision 6.3.2 Pulse Times - Table 1. The times of one complete set of roll reference signals shall be included in Table 1 of the SEDR tape and QL Tape. For the Orbiter spacecraft, one complete set of roll reference signals shall include an Fs signal, the RIP pulse which is based on that Fs signal and the RAM and NADIR pulses which are based on the RIP pulse. For the Bus spacecraft, one complete set of roll reference signals shall include an Fs signal and the RIP pulse which is based on that Fs signal. A separate data record shall be included in the tape for each set of roll reference signals which occur during the time span of the data. The signal times shall be the SCUT of each signal which have been calculated from the telemetry record as described in section 6.3.1. 6.3.3 Spacecraft Attitude. Table 2 shall tabulate the celestial latitude and celestial longitude of the spacecraft spin axis. The entries in the table will be provided as input and will not be calculated. Interpolation for spin axis attitude at times between the tabulated times shall be by using the technique described in section 6.3.6. 6.3.4 Spacecraft Spin Period - Table 3. Table 3 shall tabulate the spacecraft spin period and associated time delay (section 6.3.1.3). The entries in this table will be provided as input and will not be calculated. Linear interpolation may be used to estimate spin period and time delay at times between the entries in the table. 6.3.5 SRR Epochs - Table 4. Table 4 shall tabulate the positions of roll reference celestial bodies. The entries in this table will be input and will not be calculated. If the telemetry measurement ASRRMS indicates that a star is being used for the roll reference, the star celestial latitude and celestial longitude will be included in Table 4. If the telemetry measurement ASRRMS indicates that the Simulated ROll Reference (SIM SRR) is being used, the error between the Sun and the Sim SRR will be tabulated. Table 4 will contain enough entries to model any Sim SRR drift and allow linear interpolation between entries. The use of Table 4 to calculate spacecraft roll angle is described in section 6.4. Section No. 6.3.6 Doc. No. PC-456 04 Orig. Issue Date 7/20/77 Revision No. 3 Revision 6.3.6 Vector Interpolation for Spacecraft Attitude. 6.3.6.1 Interpolation Requirement. If the spacecraft spin axis attitude is needed at a time which is between the times for which Table 2 contains tabulated values, the intermediate attitude must be interpolated as a vector: the attitude must be interpolated in the plane which contains the two tabulated vectors. 6.3.6.2 Vector Representation of Attitudes. Let T be the time at which the interpolated attitude is desired. Let Tl and T2 be the times at which the spin axis attitude is tabulated in Table 2. [T1 < T < T2] ATT1 = vector spin axis attitude at time T1 ATT2 = vector spin axis attitude at time T2 ATT = vector spin axis attitude at time T ATT1X, ATT1Y, ATT1Z = X, Y, Z component of ATT1 ATTlX = cos (CLAT1) cos (CLON1) ATT1Y = cos (CLAT1) sin (CLON1) ATT1Z = sin (CLAT1) ATT2X, ATT2Y, ATT2Z = X, Y, Z components of ATT2 ATT2X = cos (CLAT2) cos (CLON2) ATT2Y = cos (CLAT2) sin (CLONZ) ATT2Z = sin (CLAT2) ATTX, ATTY, ATTZ = X, Y, Z components of the interpolated vector ATT Figure 6.3.6.2 shows the vector relations. Section No. 6.3.6.3 Doc. No. PC-456.O4 Orig. Issue Date 7/20/17 Revision No. 3 Revision 6.3.6.3 Minimum Angle between Vectors. Check that the angle between ATT1 and ATT2 is large enough to avoid a zero divisor later. MAGDIF = [(ATT2X - ATT1X)2 + (ATT2Y - ATT1Y)2 + (ATT2Z - ATT1Z)2112 If MAGDIF less than O.OOO17 set ATTX = ATT1X ATTY = ATT1Y ATTZ = ATT1Z 6.3.6.4 Interpolation Equations. BIGANG = 2 sin-1 (MAGDIF/2) RATIO = (T-T1)/(T2 - T1) LILANG = (BIGANG) (RATIO) ATTX = (ATT2X - ATT1X cos (BIGANG)) RATIO + ATT1X cos (LILANG) ATTY = (ATT2Y - ATT1Y cos (BIGANG)) RATIO + ATT1Y cos (LILANG) ATTZ = (ATT2Z - ATT1Z cos (BIGANG)) RATIO + ATT1Z cos (LILANG) 6.3.6.5 Interpolated Attitude. CLAT = interpolated celestial latitude CLAT = sin-1 (ATTZ) CLON = interpolated celestial longitude CLON = tan-1 (ATTY)/ATTX 6.3.6.6 Attitude Data. When spacecraft attitude is interpolated to the epochs of the SEDR Ephemeris, include the components of ATT in the Ephemeris Data File. Ephemeris File Ephemeris File Interpolated component Variable Words ATTX 63 124 and 125 ATTY 64 126 and 127 ATTZ 65 128 and 129 When spacecraft attitude is interpolated to the epochs of the Quick Look Data Record, include the components of ATT in the Ephemeris Record, File 6. Section No. 6.3.6.6 Doc. No. PC-454.O4 Orig. Issue Date 7-20-77 Revision No. 3 Revision Interpolated component Ephemeris File Word ATTX 18 ATTY 19 ATTZ 20 _____________________________________ PRL LRL P/L FILE I.D. _____________________________________ FILE l LOGISTICS RECORD (EBCDIC) _____________________________________ EOF _____________________________________ PRL LRL P/L FILE I.D. _____________________________________ PT11 RECORD FILE 2 _____________________________________ PT11 RECORD _____________________________________ EOF _____________________________________ PRL LRL P/L FILE I.D. _____________________________________ AT12 RECORD _____________________________________ FILE 3 AT12 RECORD _____________________________________ EOF _____________________________________ PRL LRL P/L FILE I.D. _____________________________________ FILE 4 SP13 RECORD _____________________________________ 5P13 RECORD _____________________________________ EOF _____________________________________ PRL LRL P/L FILE I.D. _____________________________________ SR14 RECORD _____________________________________ FILE 5 SR14 RECORD _____________________________________ EOF _____________________________________ PRL LRL P/L FILE I.D. _____________________________________ EPHEMERIS RECORD (ORBIT TODAY) _____________________________________ FILE 6 EPHEMERIS RECORD _____________________________________ EOF _____________________________________ EOF _____________________________________ PIONEER VENUS SEDR TAPE FORMAT DEFINITION REV.NO. 3 DATE 1/20/78 For Definitions Refer to Log WORD 0 WORD 1 WORD 2 WORD 3 WORD 4 WORD 5 File Table |-----------------------------------------------| -------------- | | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2| |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3| |-----------------------------------------------| RECORD 1 | *LH WD| | 2 | * P I O N E E R V E N U S S E D R * | 3 | | 4 | T A P E S E Q U E N C E N O . X X X X | 7 5 | | 6 | | 1 7 | S / C I D X X | 7 8 | O R B I T N O X X X X | 7 9 | | 10 | | 11 | | 12 | | 13 | | 14 | | 15 | | 16 | G E N E R A T E D M M M D D , Y Y | 2,7 17 | S T A R T D A T E D O Y , Y Y | 7 18 | S T A R T T I M E H H : M M | 7 19 | S T O P D A T E D O Y , Y Y | 7 20 | S T O P T I M E H H : M M | 7 21 | | 22 | D Q I P ( O R ) A | 8 |-----------------------------------------------| WORD 0 OF RECORD 1 IS LOGICAL READER WORD *LH WD = LOGICAL HEADER WORD DATA FORMAT: EBCDIC (LRL) LOGICAL RECORD LENGTH: 6 WORDS *LOGICAL RECORDS IN FILE: 22 (PRL) PHYSICAL RECORD LENGTH: 132 LOGICAL RECORDS PER PHYSICAL RECORD: 22 PIONEER VENUS SEDR FILE DEFINITION Fig 3.2.1 LOGISTIC FILE RECORD FORMAT REV.NO. 3 DATE 1/20/78 BIT |---------------------------------------------------------------| | | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^ WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| | |---------------------------------------------------------------| | 0| PRL | LRL (#words) | P/L | | 1| Number of Logical Records in This File | | 2| (SPARE) | S/C I.D. | | 3| ORBIT NUMBER | | 4| YEAR | DOY | = HEADER 5| START TIME (DATA) MS BINARY | | RECORD 6| YEAR | DOY | | 7| STOP TIME MS BINARY | | 8| (SPARE) | | 9| (SPARE) | | 10| (SPARE) | | 11| (SPARE) | | |---------------------------------------------------------------| v BIT |---------------------------------------------------------------| | | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^ WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| | |---------------------------------------------------------------| | 0|[ YEAR | DOY ] | | 1|[ ms binary (S/C UT of Fs Pulse ] | | | | | 2|[ YEAR | DOY ] | | 3|[ ms binary (S/C UT of RIP Pulse) ] | | | | | 4|[ YEAR | DOY ] | = DATA 5|[ ms binary (S/C UT of RAM Pulse ] | | RECORD | | | 6|[ YEAR | DOY ] | | 7|[ ms binary (S/C UT of NADIR Pulse ] | | 8| DATA QUALITY FLAG 1 Delta - R*8 | | 9| (SPARE) | | 10| A | | B | | C | | D | | | 11| UCLA Pulse time correction (EBCDIC) | | |---------------------------------------------------------------| v Logical Record Length : 12 words A: STRM Data format : Binary B: CICK Physical Record Length : 120 words C: SRRM No. Logical Records/Physical Record : 10 D: Fire SRRM: 0 = unk Fire: 0 = Norm 1 = Star (22,23) 1 = Fire 2 = Sim 3 = Sun PIONEER VENUS SEDR TAPE FILE FIG 3.2.1 DEFINITION FILE 2 TABLE 1 - PULSE TIMES (Plll) LOGICAL RECORD FORMAT REV. NO. 3 DATE 1/20/78 BIT |---------------------------------------------------------------| | | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^ WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| | |---------------------------------------------------------------| | 0| PRL | LRL (#words) | P/L | FILE ID | | 1| Number of logical Records in This File | = HEADER 2| (SPARE) | S/C ID | | RECORD 3| ORBIT NUMBER | | 4| (SPARE) | | |---------------------------------------------------------------| v BIT |---------------------------------------------------------------| | | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^ WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| | |---------------------------------------------------------------| | 0|[ S/C UT YEAR DOY ] | | 1|[ ms binary ] | = DATA 2| CLAT (celestial latitude)(in deg. dec deg) | | RECORD 3| CLON (celestial longitude)(in deg. dec deg)| | 4| (SPARE) | | |---------------------------------------------------------------| v Logical Record Length : 5 words Data Format : Single Precision Flt. Pt. Binary Physical Record Length: 5O words Logical Records/Physical Record : 10 PIONEER VENUS SEDR TAPE FILE FIG 3.2.1 DEFINITION FILE 3 TABLE 2 - S/C ATTITUDE (ATl2) LOGICAL RECORD FORMAT REV. NO. 3 DATE 1/20/78 BIT |---------------------------------------------------------------| | | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^ WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| | |---------------------------------------------------------------| | 0| PRL | LRL (# words) | P/L |FILE I.D | | 1| Number of Logical Records in This File | | 2| (SPARE) | S/C I.D. | | 3| ORBIT NUMBER | = HEADER 4| YEAR | DOY | | RECORD 5| START DATA TIME | MS BINARY | | 6| YEAR | DOY | | 7| STOP DATA TIME | MS BINARY | | 8| SPARE | | 9| SPARE | | |---------------------------------------------------------------| v BIT |---------------------------------------------------------------| | | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^ WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| | |---------------------------------------------------------------| | 0|[ S/C UT YEAR | DOY ]| | 1|[ ms binary ]| | 2| SPIN PERI0D (in sec. dec secs) | | 3| TIME DELAY (in sec. dec secs) | = DATA 4| (SPARE) | | RECORD 5| (SPARE) | | 6| (SPARE) | | 7| (SPARE) | | 8| (SPARE) | | 9| (SPARE) | | |---------------------------------------------------------------| v Time Delay = delay from SRR Pulse to Fs Pulse. Logical Record Length: 10 words Data Format : Single Precision Flt. Pt., Binary Physical Record Length: 40 words # Logical Records/Physical Record: 4 PIONEER VENUS SEDR TAPE FILE DEFINITION FILE 4 TABLE 3 - S/C SPIN RECORD (SPl3) LOGICAL RECORD FORMAT REV. NO. 3 DATE 1/20/78 BIT |---------------------------------------------------------------| | | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^ WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| | |---------------------------------------------------------------| | 0| PRL | LRL (# words) | P/L |FILE I.D | | 1| Number of Logical Records in This File | | 2| (SPARE) | S/C I.D. | | 3| ORBIT NUMBER | = HEADER 4| YEAR | DOY | | RECORD 5| START DATA TIME | MS BINARY | | 6| YEAR | DOY | | 7| STOP DATA TIME | MS BINARY | | 8| SPARE | | 9| SPARE | | |---------------------------------------------------------------| v BIT |---------------------------------------------------------------| | | | | | | | | | | |1|1|1|1|1|1|1|1|1|1|2|2|2|2|2|2|2|2|2|2|3|3| ^ WD |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1| | |---------------------------------------------------------------| | 0|[ S/C UT YEAR | DOY ]| | 1|[ ms binary ]| | 2| SPIN PERI0D (in sec. dec secs) | | 3| TIME DELAY (in sec. dec secs) | = DATA 4| (SPARE) | | RECORD 5| (SPARE) | | 6| (SPARE) | | 7| (SPARE) | | 8| (SPARE) | | 9| (SPARE) | | |---------------------------------------------------------------| v Logical Record Length : 10 words Data Format : Single Precision, Flt. Pt. Binary Physical Record Length : 100 words #Logical Records/Physical Record : 10 PIONEER VENUS SEDR TAPE FILE DEFINITIONS FILE 5 TABLE 4 - SRR EPOCHS (SR14) LOGICAL RECORD FORMAT REV. NO. 3 DATE 1/20/78 EPHEMERIS HEADER RECORD BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 _________________________________________________________________ word 0| PRL | LRL (# words) | P/L |FILE ID| |_______________________________________________________________| 1| Number of Logical Records in This File | |_______________________________________________________________| 2| (spare) | S/C I.D. | |_______________________________________________________________| 3| ORBIT NUMBER | |_______________________________________________________________| 4| S/C UT YEAR | DOY S/C UT| |_______________________________________________________________| 5| START TIME - MILLISECONDS | |_______________________________________________________________| 6| S/C UT YEAR | DOY S/C UT| |_______________________________________________________________| 7| STOP TIME - MILLISECONDS | |_______________________________________________________________| 8| SPARE | |_______________________________________________________________| 9| SPARE | |_______________________________________________________________| . . . _________________________________________________________________ 282| SPARE | |_______________________________________________________________| 283| SPARE | |_______________________________________________________________| All data is in IBM 360 binary format, 2 and 4 byte integers EPHEMERIS DATA RECORD LOGICAL RECORD LENGTH: 284 1. ALL DATA IS IN IBM 360 format, DP PHYSICAL RECORD LENGTH: 284 2. Except for integer variables, all variables are in double-precision floating point (data records). including calculated attitude, nadir and ram. NO. OF LOGICAL RECORDS PER PHYSICAL RECORD: 1 3. File order is in S/C UT ascending order. BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 WORD __________________________________________________________________________ 0 | S/C YEAR | S/C DOY | NAME VAR |______________________________________________________________|__________ 1 | S/C UT in binary |SCUT 1 |______________________________________________________________|__________ 2-3|DP Julian Date, Days (elapsed days from |JULDAT |Noon, 1 Jan. 4713 B.C. | 2 |______________________________________________________________|__________ 4-5|Gregorian Calendar Date (2 integer words which | |represent the vigesimal date) based on number 20 | VIGDAT 3 |______________________________________________________________|__________ 6-7|ET - UTC, set (Universal Time Co-ordinated) |ETMUTC 4 |______________________________________________________________|__________ 8-9|Range rate of probe. km/sec + |RANGRF 5 |___________________________________________________|__________|__________ 10-11|Magnitude of velocity vector, km/sec (speed of S/C)|Geocentric|MAGVEL 6 |___________________________________________________|__________|__________ 12-13|Earth.probe range, km (radius to S/C) + |REARPR 7 |______________________________________________________________|__________ 14-15|Range to probe, km + |MRANGE 8 |___________________________________________________|__________|__________ 16-17|Probe inertia velocity, km/sec | |MMAGVF 9 |___________________________________________________|__________|__________ 16-19|Probe inertial path angle, deg |HELIO- |HINFTP 10 |___________________________________________________|CENTRIC __|__________ 20-21|Celestial latitude of probe, deg | |CELLTF 11 |___________________________________________________|__________|__________ 22-23|Celestial longitude of probe, deg | |CELLNF 12 |___________________________________________________|__________|__________ 24-25|Celestial latitude of Earth, deg | |CELLTE 13 |___________________________________________________|__________|__________ 26-27|Celestial longitude of Earth, deg | |CELLNE 14 |___________________________________________________|__________|__________ 28-29|X component of S/C in Sun-Earth line, km |HELIO- |XSCSEL 15 |___________________________________________________|CENTRIC __|__________ 30-31|Y component of S/C in Sun.Earth line, km | |YSCSEL 16 |___________________________________________________|__________|__________ 32-33|Z component of S/C in Sun.Earth line, km | |ZSCSEL 17 |___________________________________________________|__________|__________ 34-35|Sun-probe distance in Sun-Earth X-Y plane, km | | |(projection of Sun-S/C vector onto the X-Y plane | |SPSE 18 |___________________________________________________|__________|__________ 36-37| Longitude of S/C in Sun-Earth line system, deg + |LNPSEL 19 ______________________________________________________________|__________ Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft and not to the separated Large or Small Probes. Fig 3.2.1 EPHEMERIS DATA RECORD con't BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var WORD _________________________________________________________________________ 38-39 |X component of geocentric r of S/C, km + |XPGSFF 20 |____________________________________________|________________|__________ 40-41 |Y component of geocentric r of S/C, km | |YPGSFF 21 |____________________________________________|________________|__________ 42-43 |Z component of geocentric r of S/C, km | |ZPGSFF 22 |____________________________________________|________________|__________ 44-45 |X component of geocentric r of S/C, km/sec | |DXPGSF 23 |____________________________________________|________________|__________ 46-47 |Y component of geocentric r of S/C, km/sec | |DYPGSF 24 |____________________________________________|________________|__________ 46-49 |Z component of geocentric r of S/C, km/sec | |DZPGSF 25 |____________________________________________|________________|__________ 50-51 |X component of heliocentric r of S/C, km | |XPHSFF 26 |____________________________________________|________________|__________ 52-53 |Y component of heliocentric r of S/C, km | Space-fixed |YPHSFF 27 |____________________________________________| Coordinates ___|__________ 54-55 |Z component of heliocentric r of S/C, km | FERP |ZPHSFF 28 |____________________________________________| Earth Mean ___|__________ 56-57 |X component of heliocentric r of S/C, km/sec| Equinox & |DXPHSF 29 |____________________________________________| Ecliptic of ___|__________ 56-55 |Y component of heliocentric r of S/C, km/sec| 1950.0 |DYPHSF 30 |____________________________________________|________________|__________ 60-61 |Z component of heliocentric r of S/C, km/sec| |DZPHSF 31 |____________________________________________|________________|__________ 62-63 |X component of body 1 - S/C r, km |+ |XP1SFF 32 |____________________________________________||_______________|__________ 64-65 |Y component of body 1 - S/C r, km || |YP1SFF 33 |____________________________________________||_______________|__________ 66-67 |Z component of body 1 - S/C r, km || |ZP1SFF 34 |____________________________________________||_ Body __|__________ 68-69 |X component of body 1 - S/C r, km/sec || 1 = Venus |DXP1SF 35 |____________________________________________||_______________|__________ 70-71 |Y component of body 1 - S/C r, km/sec || |DYP1SF 36 |____________________________________________||_______________|__________ 72-73 |Z component of body 1 - S/C r, km/sec || |DZP1SF 37 |____________________________________________||_______________|__________ 74-75 |Body 1 - S/C range, km || |B1MAGR 38 |____________________________________________||_______________|__________ 76-77 |Body l - S/C velocity magnitude, km/sec ++ |B1MAGV 39 |_____________________________________________________________|__________ 78-79 |Latitude of probe, deg + |EALATP 40 |____________________________________________|________________|__________ 80-81 |Longitude of probe, deg | |EALOMP 41 |____________________________________________|Body Fixed Earth|__________ 82-83 |Velocity magnitude of probe relative to body|(see EN/1) |EAVELP 42 |km/sec. | | |____________________________________________|________________|___________ 84-85 |Body fixed path angle of probe. deg | |EAPTHP 43 |____________________________________________|________________|__________ 86-87 |Body fixed azimuth angle of probe. deg + |EAAZIP 44 _________________________________________________________________________ Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft and not to the separated Large or Small Probes. EN/1 -- Earth true equator of date and Greenwich Meridian Fig 3.2.1 EPHEMERIS DATA RECORD con't BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var WORD _________________________________________________________________________ 88-89| Latitude of probe. deg + |B1LATP 45 |___________________________________________|_________________|__________ 90-91| Longitude of probe. deg | |B1LOMP 46 |___________________________________________|Body Fixed _|__________ 92-93| Velocity magnitude of probe relative to |Body 1 = Venus |B1VELP 47 | body km/sec |(see EN/2) | |___________________________________________|_________________|__________ 94-95| Body fixed path angle of probe. deg | |B1PTHP 48 |___________________________________________|_________________|__________ 96-97| Body fixed azimuth angle of probe. deg + |B1AZIP 49 |_____________________________________________________________|__________ 98-100| Earth-probe-body 1 angle, deg + |EPB1AN 50 |___________________________________________|_________________|__________ 100-101| Earth-probe-sun angle, deg | |EPSUAN 51 |___________________________________________| Angle Group __|__________ 102-103| Sun-Earth-probe angle, deg | All angles in |SEPANG 52 |___________________________________________| degrees __|__________ 104-105| Earth-Sun-probe angle, deg | |ESPANG 53 |___________________________________________|_________________|__________ 106-107| Sun-probe-body 1 angle, deg | |SPB1AN 54 |___________________________________________|_________________|__________ 108-109| Body 1-Earth-probe angle, deg + |B1EPAN 55 |_____________________________________________________________|__________ 110-111| Flag for periapsis (See EN/3) |PERIAP 56 |_____________________________________________________________|__________ 112-113| X-coordinate of XROLL + + |XROLLX 57 |______________________________|____________|_________________|__________ 114-115| Y-coordinate of XROLL | | |XROLLY 58 |______________________________|____________|_________________|__________ 116-117| Z-coordinate of XROLL | | |XROLLZ 59 |______________________________|____________|_________________|__________ 118-119| X-coordinate of YROLL | | |YROLLX 60 |______________________________| Attitude |Spacecraft - ____|__________ 120-121| Y-coordinate of YROLL | Data |Centered |YROLLY 61 |______________________________|____________|Non-Rotating ____|__________ 122-123| Z-coordinate of YROLL | |Coordinates |YROLLZ 62 |______________________________|____________|_________________|__________ 124-125| X-coordinate of ATT | | |ATTX 63 |______________________________|____________|_________________|__________ 126-127| Y-coordinate of ATT | | |ATTY 64 |______________________________|____________|_________________|__________ 128-129| Z-coordinate of ATT + | |ATTZ 65 |___________________________________________|_________________|__________ 130-131| NADROL | |NADROL 66 |___________________________________________|_________________|__________ 132-133| NADLOK | |NADLOK 67 |___________________________________________|_________________|__________ 134-135| RAMROL | |RAMROL 68 |___________________________________________|_________________|__________ 136-137| RAMLOK + |RAMLOK 69 ______________________________________________________________|__________ Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft and not to the separated Large or Small Probes. EN/2 -- Venus true equator of date and Prime Meridian EN/3 -- PERIAP = 0. for no closest approach, = 1 for periapsis to PCB, = 2 for apoapsis to PCB Fig 3.2.1 EPHEMERIS DATA RECORD con't BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var WORD _________________________________________________________________________ 138-153| SPARES | 70-77 |_____________________________________________________________|__________ 154-155|Celestial latitude of probe, deg + | DECPI 78 |___________________________________________|_________________|__________ 156-157|Celestial longitude of probe, deg | | RAP1 79 |___________________________________________|_________________|__________ 158-159|Flight-path angle of probe, deg | | PTHP1 80 |___________________________________________|_________________|__________ 160-161|Azimuth angle of probe, deg | | AZP1 81 |___________________________________________|_________________|__________ 162-163|Range rate of probe. km/sec | | DR1 82 |___________________________________________|_________________|__________ 164-165|X-component of Earth position, km | (EC) | XE1 83 |___________________________________________|_________________|__________ 166-167|Y-component of Earth position, km | (EC) | YE1 84 |___________________________________________|_________________|__________ 168-169|Z-component of Earth position, km | (EC) | ZE1 85 |___________________________________________|_________________|__________ 170-171|X-component of Earth velocity, km/sec | (EC) | DXE1 86 |___________________________________________|_________________|__________ 172-173|Y-component of Earth velocity, km/sec | (EC) | DYE1 87 |___________________________________________|_________________|__________ 174-175|Z-component of Earth velocity, km/sec | (EC) | DZE1 88 |___________________________________________|_________________|__________ 176-177|Venus-to-Earth range, km | Venus Centered | RE1 89 |___________________________________________| Earth Mean _|__________ 178-179|Celestial latitude of Earth direction, deg | Equinox & | DECE1 90 |___________________________________________| Ecliptic of _|__________ 180-181|Celestial longitude of Earth direction, deg| 1950.0 | RAE1 91 |___________________________________________|_________________|__________ 182-183|X-component of Sun position. km | (EC) | XS1 92 |___________________________________________|_________________|__________ 184-185|Y-component of Sun position, km | (EC) | YS1 93 |___________________________________________|_________________|__________ 186-187|Z-component of Sun position, km | (EC) | ZS1 94 |___________________________________________|_________________|__________ 188-189|X-component of Sun velocity, km/sec | | DXS1 95 |___________________________________________|_________________|__________ 190-191|Y-component of Sun velocity, km/sec | | DYS1 96 |___________________________________________|_________________|__________ 192-193|Z-component of Sun velocity, km./sec | | DZS1 97 |___________________________________________|_________________|__________ 194-195|Venus-to-Sun range, km | | RS1 98 |___________________________________________|_________________|__________ 196-197|Celestial latitude of Sun direction, deg | | DESC1 99 |___________________________________________|_________________|__________ 198-199|Celestial longitude of Sun direction. deg + | RAS1 100 |_____________________________________________________________|__________ Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft and not to the separated Large or Small Probes. Fig 3.2.1 EPHEMERIS DATA RECORD con't BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var WORD _________________________________________________________________________ 200-201|Orbit semimajor axis, km + + | SMA 101 |_________________________________________|_____|_____________|__________ 202-203|Orbit eccentricity | | | ECC 102 |_________________________________________|_____|_____________|__________ 204-205|Time from periapsis, secs | | | TFP 103 |_________________________________________|_____|_____________|__________ 206-207|Radius of closest approach, km | | | RCA 104 |_________________________________________|_____|_____________|__________ 208-209|orbit period, day | | | PER 105 |_________________________________________|Conic|_____________|__________ 210-211|Spacecraft true anomaly, deg |Group| | TA 106 |_________________________________________|_____|Venus |__________ 212-213|Orbit inclination, deg | |Centered | INCL 107 |_________________________________________|_____|Earth Mean |__________ 214-215|Longitude of ascending node, deg | |Equinox & | LANL 108 |_________________________________________|_____|Ecliptic of |__________ 216-217|Argument of periapsis, deg | |1950.0 | APF1 109 |_________________________________________|_____|_____________|__________ 218-219|X-component of unit vector to periapsis | | | PX1 110 |_________________________________________|_____|_____________|__________ 220-221|Y-component of unit vector to periapsis | | | PY1 111 |_________________________________________|_____|_____________|__________ 222-223|Z-component of unit vector to periapsis | | | PZ1 112 |_________________________________________|_____|_____________|__________ 224-225|X-component of unit normal to orbit plane| | | WX1 113 |_________________________________________|_____|_____________|__________ 228-227|Y.component of unit normal to orbit plane| | | WY1 114 |_________________________________________|_____|_____________|__________ 228-229|Z-component of unit normal to orbit plane+ | | WZ1 115 |_______________________________________________|_____________|__________ 230-231|Sun-Venus-probe angle, deg + | | S200P 116 |_________________________________________|Angle|_____________|__________ 232-233|Sun-Earth-Venus angle, deg +Group| | SE200 117 |_______________________________________________|_____________|__________ 234-235|X-component of probe position, km | | XP1 118 |_______________________________________________|_____________|__________ 236-237|Y-component of probe position, km | | YP1 119 |_______________________________________________|_____________|__________ 238-239|Z-component of probe position, km | | ZP1 120 |_______________________________________________|_____________|__________ 240-241|X-component of probe velocity, km/sec | | DXP1 121 |_______________________________________________|_____________|__________ 242-243|Y-component of probe velocity. km/sec | | DYP1 122 |_______________________________________________|_____________|__________ 244-245|Z-component of probe velocity, km/sec + | DZP1 123 |_____________________________________________________________|__________ Note: The term "probe" refers to the Multiprobe or Orbiter spacecraft and not to the separated Large or Small Probes. Fig 3.2.1 EPHEMERIS DATA RECORD con't BIT 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 name var WORD _________________________________________________________________________ 246-247|X-component of Earth position, km (EQ) + | XE1 124 |_______________________________________________|_____________|__________ 248-249|Y-component of Earth position, km (EQ) | | YE1 125 |_______________________________________________|_____________|__________ 250-251|Z-component of Earth position, km (EQ) | | ZE1 126 |_______________________________________________|_____________|__________ 252-253|X-component of Sun position, km (EQ) | | XS1 127 |_______________________________________________|_____________|__________ 254-255|Y-component of Sun position, km (EQ) |Venus | YS1 128 |_______________________________________________|Centered |__________ 256-257|Z-component of Sun position, km (EQ) |Earth Mean | ZS1 129 |_______________________________________________|Equinox & |__________ 258-259|X-component of probe position, km |Ecliptic of | XP2 130 |_______________________________________________|1950.0 |__________ 260-261|Y-component of probe position, km | | YP2 131 |_______________________________________________|_____________|__________ 262-263|Z-component of probe position, km | | ZP2 132 |_______________________________________________|_____________|__________ 264-265|X-component of probe velocity, km/sec | | DXP2 133 |_______________________________________________|_____________|__________ 266-267|Y-component of probe velocity, km/sec | | DYP2 134 |_______________________________________________|_____________|__________ 268-269|Z-component of probe velocity. km/sec+ + | DZP2 135 |_____________________________________________________________|__________ 270-271|Celestial latitude of Earth-to-probe direction,deg (see EN/4)| DECP3 136 |_____________________________________________________________|__________ 272-273|Celestial longitude of Earth-to-probe direction,deg | RAP3 137 |_____________________________________________________________|__________ 274-279| (SPARES - Double Precision Zeros) | 138-140 |________________________________________________________________________ EN/4 Earth-centered, Earth mean Equinox & Ecliptic of 1950.0 Fig 3.2.1 The next nine pages contain graphics. Please see TIFF files.