swh:1:snp:63e2d142f91fc04ec33789d9d7bb85f3bef72e05
Tip revision: 66d8e606a8d996ded60bc81d5edf319142a5fad9 authored by Ron Burkey on 04 October 2021, 11:49:55 UTC
Merge branch 'master' of https://github.com/virtualagc/virtualagc
Merge branch 'master' of https://github.com/virtualagc/virtualagc
Tip revision: 66d8e60
ORBITAL_INTEGRATION_PROGRAM.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: ORBITAL_INTEGRATION_PROGRAM.agc
## Purpose: A module for revision 0 of BURST120 (Sunburst). It
## is part of the source code for the Lunar Module's
## (LM) Apollo Guidance Computer (AGC) for Apollo 5.
## Assembler: yaYUL
## Contact: Hartmuth Gutsche <hgutsche@xplornet.com>.
## Website: www.ibiblio.org/apollo/index.html
## Mod history: 2016-09-30 RSB Created draft version.
## 2016-10-26 HG Transcribed
## 2016-10-31 RSB Typos.
## 2016-11-01 RSB More typos.
## 2016-12-06 RSB Comments proofed using octopus/ProoferComments,
## changes made.
## 2017-06-12 MAS Just a couple of typos found while updating for
## Sunburst 37.
## Page 776
# FBR3 SETS UP A TIMESTEP CALL TO KEPLER.
FBR3 DLOAD SR3
H
SR3R DAD
TC
STODL TAU
EARTHTAB +9D
DMP SRR
DT/2
12D
DAD
TET
STORE TET
## Page 777
# THIS ORBITAL KEPLER SUBROUTINE FINDS THE POSITION AND VELOCITY OF THE VEHICLE AFTER TIME FOUND IN GIVENT
# SINCE RECTIFICATION TO POSITION RRECT AND VELOCITY VRECT. THE RESULTING POSITION AND VELOCITY ARE LEFT IN
# FOUNDR AND FOUNDV, RESPECTIVELY.
KEPLER VLOAD SETPD # UNIT OF RECTIFICATION POSITION TO 0
RRECT
0
UNIT PDDL # AND LENGTH OF ORIGINAL IN 6
36D
PDVL # LENGTH OF POSITION AT RECTIFICATION.
VRECT
VSQ ROUND
DMP DSU
6 # LENGTH OF POSITION AT RECTIFICATION
DP1/4
SL2R PUSH # A4 TO REGISTER 8
SR2 DCOMP
DAD DDV
DP1/4
6
PDVL DOT # ALPHA TO REGISTER 10
RRECT
VRECT
ROUND PDVL # A1 TO REGISTER 12
RCV
UNIT DOT
VCV
PDDL # IR/2.VC IN 14D.
36D
STODL ALPHAM # RC IN ALPHAM
DT/2
SR3 SR3R
DDV AXT,2
ALPHAM
10D # MAX ITERATION COUNT IS 10
## Page 778
PDDL DDV # Q IN 16
DP1/4
ALPHAM
DSU DMPR
10D # 1/4RC : ALPHA
16D # Q( )
DMPR DMPR
16D # QQ( )
DP1/3
SL3 SL3
PDDL DMPR
14D
16D
SL4 PUSH # 16(UR/2.VC)Q IN 20
BDSU DMPR
DP1/2
BDSU DSU
DP1/2
DMP SL1R
DAD SSP
XKEP
S2
1
STORE XKEP
## Page 779
# ITERATING EQUATIONS - GIVEN X IN MPAC, FIND TIME OF FLIGHT.
KTIMEN+1 DSQ ROUND # FORM ALPHA X-SQUARED AND CALL S AND C
DMP SL2R
10D
SETPD CALL # SET PD INDICATOR TO 16
16D
S(X)C(X)
DMP SL4
XKEP
DMP SL1
XKEP
DMP SL1R
XKEP
STORE 23D # A3
DMPR PDDL
8D
XKEP
DMP SL4
16D # VALUE OF C
SL1 DMP
XKEP
SL2R
STORE 21D # A2
DMP SR1R
12D # A1
DAD
PDDL DMPR
6
XKEP
DAD
PUSH BDSU # COMPARE WITH GIVEN TIME OF FLIGHT
GIVENT
STORE 16D # DIFFERENCE TO REGISTER 16
EXIT
## Page 780
DUMPDUMP TC INTPRET # FOR DUMP ONLY *******
ABS DSU
KEPSILON # SEE IF WITHIN EPSILON OF GIVEN TIME.
BMN TIX,2 # IF SO, GET R AND V AND EXIT.
GETRANDV
GETNEWX
GOTO
GETRANDV
GETNEWX DLOAD DMP
10D # ALPHA
23D # A3
SL2R BDSU
XKEP
DMP SL4R
12D # A1
STODL 18D
21D # A2
DMP SL1R
8D # A4
DAD
DAD PDDL
6 # R0
16D
DDV DAD
18D
XKEP
STCALL XKEP
KTIMEN+1
## Page 781
# SUBROUTINE FOR COMPUTING THE UNIVERSAL CONIC FUNCTIONS S(X) AND C(X). THE ACTUAL OUTPUT OF THIS ROUTINE
# CONSISTS OF SCALED VERSIONS DEFINED AS FOLLOWS -
# S (X) = S(64X) C (X) = C(64X)/4
# S S
# IT IS ASSUMED THAT THE INPUT ARRIVES IN MPAC,MPAC+1 AND THAT IT LIES BETWEEN -30/64 AND 40/64. UPON EXIT,
# S(X) WILL BE LEFT IN MPAC,MPAC+1 AND C(X) ON TOP OF THE PUSHDOWN LIST.
S(X)C(X) STORE 34D # X TO 34D
RTB DSQ
A(X)
ROUND PUSH
STORE 36D # A SQUARED TO 36D
DMP SL1R
34D # 2 2
BDSU DMPR # C (X) = A (.25 - 2XA ) TO PD LIST
POS1/4 # S
36D
PDDL SR2R # 2
PDDL RTB # A /4 TO PD LIST
34D
B(X)
DSQ ROUND
PDDL DMPR # B SQUARED TO PD LIST
34D
36D
BDSU DMPR # 2 2 2
POS1/16 # LEAVES S (X)=B (.0625-A X)+A /4 IN MPAC
DAD ITCQ # S
-1/12 2DEC -.1 # DONT MOVE.
## Page 782
# A AND B POLYNOMIALS WHOSE COEFFICIENTS WERE OBTAINED WITH THE *AUTOCURVEFIT* PROGRAM.
A(X) TC POLY
DEC 4
2DEC 7.071067810 E-1
2DEC -4.714045180 E-1
2DEC 9.42808914 E-2
2DEC -8.9791893 E-3
2DEC 4.989987 E-4
2DEC -1.79357 E-5
TC DANZIG
B(X) TC POLY
DEC 4
2DEC 8.164965793 E-1
2DEC -3.265986572 E-1
2DEC 5.90988980 E-2
2DEC -4.0085592 E-3
2DEC 2.781528 E-4
2DEC -1.25610 E-5
TC DANZIG
## Page 783
# ROUTINE FOR OBTAINING R AND V, NOW THAT THE PROPER X HAS BEEN FOUND.
GETRANDV DLOAD SETPD
21D # A2 FROM LAST ITERATION
25D
DCOMP VXSC
0 # UNIT OF GIVEN POSITION VECTOR
PDDL DSU
18D # LAST VALUE OF T
23D # LAST VALUE OF A3
SL2 VXSC
VRECT
VAD VSL1 # ADDITION MUST BE DONE IN THIS ORDER
PUSH VAD
RRECT
VAD STADR
STORE FOUNDR # RESULTING CONIC POSITION
ABVAL
STODL 16D
10D # ALPHA
DMP SL2R
23D # A3
DSU DDV
XKEP
16D # LENGTH OF FOUND POSITION
VXSC VSL2
0 # UNIT OF RECTIFICATION POSITION
PDDL SR1
16D
DSU DDV
21D
16D
VXSC VAD
VRECT
VSL1
STCALL FOUNDV # THIS COMPLETES THE CALCULATION
HBRANCH
## Page 784
# THE POSTRUE ROUTINES SET UP THE BETA VECTOR AND OTHER INITIAL CONDITIONS FOR THE NEXT ACCOMP.
POSTRUE SSP VLOAD # TIME STEP CALLS TO KEPLER RETURN HERE
SCALEA
4
ALPHAV
VSR VAD
10D
RCV # POSITION OUTPUT OF KEPLER
LXA,2 BOF
DIFEQCNT
WMATFLAG
NOSAVE1
STORE VECTAB,2
NOSAVE1 SSP SSP # SETS UP SCALE B AND GMODE
SCALEB
14D
GMODE
2
STORE BETAV
## Page 785
# AGC ROUTINE TO COMPUTE ACCELERATION COMPONENTS.
ACCOMP VLOAD UNIT
ALPHAV
STODL ALPHAV
36D
STORE ALPHAM
BOV
ACCOMP2 # TURN OFF OVERFLOW INDICATOR
ACCOMP2 VLOAD VSR1
BETAV
VSQ SETPD
0
NORM ROUND
S1
PDDL NORM # NORMED B SQUARED TO PD LIST
ALPHAM # NORMALIZE (LESS ONE) LENGTH OF ALPHA
X1 # SAVING NORM SCALE FACTOR IN X1
SR1 PDVL
BETAV # C(PDL+2) = ALMOST NORMED ALPHA
UNIT
STODL BETAV
36D
STORE BETAM
NORM BDDV # FORM NORMALIZED QUOTIENT ALPHAM/BETAM
X2
SR1R PUSH # C(PDL+2) = ALMOST NORMALIZED RHO.
LXC,2 XAD,2
X2 # C(X2) = -SCALE(RHO) + 1
SCALEA # = -S(B)-N(B)+S(A)+N(A)+1
XAD,2 XSU,2
X1
SCALEB
INCR,2 SR*
2
0,2
PUSH SR2R # RHO/4 PD+6
PDVL DOT
ALPHAV
BETAV
SL1R BDSU # (RHO/4) - 2(ALPHAV/2.BETAV/2)
PUSH DMPR # TO PDL+6
4
## Page 786
PUSH DAD # Q/4 = RHO(C(PDL+4)) TO PD+8D
DQUARTER # (Q+1)/4 TO PD+10D
PUSH SQRT # 3/2
DMPR PUSH # ((Q+1)/4) TO PD+12D
10D
SL1 DAD
DQUARTER # 3/2
PDDL DAD # (1/4)+2((Q+1)/4) TO PD+14D
10D
DP1/2
DMPR SL1
8D
DAD DDV
THREE/8
14D
DMPR VXSC
6
BETAV # -
PDVL VSR3 # (G/2)(C(PD+4))B/2 TO PD+16D
ALPHAV
VAD PUSH # A12 + C(PD+16D) TO PD+16D
DLOAD DMP
0
12D # -
NORM ROUND # GAMMA TO PD+22D
S2 # - SCALE(GAMMA)-1 TO X1
BDDV LXC,1
2
X2 # C(X2) = SCALE(RHO)
XAD,1 XAD,1
S2 # C(S2) = N((B.B/4)(....)3/2)
S1 # C(S1) = N(B.B/4)
XAD,1 XAD,1
SCALEB
SCALEB
DCOMP VXSC
16D # RESULT OF PRECEDING EQUATION
PUSH CGOTO
GMODE
GTABLE
GTABLE CADR GMODE10
CADR GMODE11
CADR GMODE12
## Page 787
# THE GMODE12 ROUTINE SETS UP THE SECONDARY BODY DISTURBING ACCELERATION FOR ACCOMP.
GMODE12 VSL* # -SCALE(GAMMA)-1 IS LEFT IN X1.
31D,1 # ADJUST GAMMA TO SCALE OF -32
STOVL FV
BETAV
STODL ALPHAV # BETA VECTOR INTO ALPHA FOR NEXT ACCOMP
BETAM
STORE ALPHAM
BOFF CALL
MIDFLAG
OBLATEST
MOONPOS
STORE BETAV # MOON(EARTH) POSITION WILL BE BETA NEXT
LXA,1 BOF
DIFEQCNT # SAVE R/QV IN VECTAB FOR W-MATRIX UPDATE
WMATFLAG
NOSAVE2
STORE VECTAB +6,1
NOSAVE2 AXT,2 XCHX,2 # SETUP ALPHAM AND SCALEA
19D # SCALE FOR R/QV
SCALEB # SWAP SCALEB AND X2
SXA,2 GOTO
SCALEA
ACCOMP2 # ENTRY IF UNIT(ALPHAV) AVAILABLE
## Page 788
# THE GMODE11 ROUTINE SETS UP THE SUNS DISTURBING ACCELERATION.
GMODE11 LXC,2 CALL # SET X2 TO TABLE OF PROPER CONSTANTS
PBODY
ADDTOFV
CALL # BARICENTER-TO-SUN POSITION VECTOR.
SUNPOS # LEAVES VECTOR IN PDL
LXA,1 VLOAD* # COMPUTE R/PS USING CORRECT TABLE FOR
DIFEQCNT # MASS RATIO, ETC.
VECTAB +6,1
VXSC* VAD
6,2 # USE SCALAR AT ENTRY 6 IN THE TABLE
AXT,1 SXA,1
28D
SCALEB # SET SCALEB AND RETURN TO ACCOMP
STCALL BETAV
ACCOMP2
# THE GMODE10 ROUTINE ADDS IN THE SUNS PERTURBING ACCELERATION AND COMPUTES THE OBLATENESS CONTRIBUTION
GMODE10 LXC,2 INCR,2
PBODY
DEC -3
CALL
ADDTOFV
OBLATEST BON
MOONFLAG
NBRANCH
## Page 789
# THE OBLATE ROUTINE COMPUTES THE ACCELERATION DUE TO THE EARTHS OBLATENESS. 2T USES THE UNIT OF THE VEHICLE
# POSITION VECTOR FOUND IN ALPHAV AND THE DISTANCE TO THE CENTER IN ALPHAM. THIS IS ADDED TO THE SUM OF THE
# DISTURBING ACCELERATIONS IN FV AND THE PROPER DIFEQ STAGE IS CALLED VIA X1.
OBLATE DLOAD
ALPHAV +4 # Z COMPONENT OF POSITION IS COS PHI
SETPD DMPR
0
3/4
PDDL DSQ # P2:/8 TO REGISTER 0
ALPHAV +4
SL3 DMPR
15/16
DSU PUSH # P3:/4 TO REGISTER 2
3/8
DMPR DMPR
ALPHAV +4
7/12
SL1 PDDL # P4:/16 TO REGISTER 4
0
DMPR BDSU
2/3
PUSH DMPR # BEGIN COMPUTING P5:/128
ALPHAV +4
DMPR PDDL
9/16
2
DMPR BDSU # FINISH P5:/128 AND TERM USING UNIT
5/128 # POSITION VECTOR AT ALPHA
DMP SL2
J4REQ/J3
DDV DAD
ALPHAM
4
DMPR DDV
2J3RE/J2
ALPHAM
DAD VXSC
2
ALPHAV
STODL ALPHAV
## Page 790
DMP SL1 # COMPUTE TERM USING IZ
J4REQ/J3
DDV DAD
ALPHAM
PDDL SR3
2J3RE/J2
DMPR
DDV DAD
ALPHAM
BDSU
ALPHAV +4
STODL ALPHAV +4
ALPHAM
DSQ DSQ
NORM BDDV
X1
J2REQSQ
VXSC INCR,1
ALPHAV
4
VSL* VAD # SHIFTS LEFT ON +, RIGHT ON -.
0,1
FV
STORE FV
NBRANCH SLOAD LXA,1
DIFEQCNT
MPAC
DMP CGOTO
-1/12
MPAC
DIFEQTAB
DIFEQTAB CADR DIFEQ+0
CADR DIFEQ+1
CADR DIFEQ+2
ADDTOFV DLOAD* # SETS UP S1 AND S2 PER PRIMARY BODY TABLE
0,2
STOVL S1
22D
XAD,1 VXSC*
S1
1,2
VSL* VAD
31D,1
FV
STORE FV
ITCQ
## Page 791
# BEGIN INTEGRATION STEP WITH RECTIFICATION TEST.
TIMESTEP VLOAD # MOVE TEMPORARY DELTA AND NU VECTORS
TNUV # TO WORKING STORAGE
STOVL ZV
TDELTAV
STORE YV
ABVAL DSU # RECTIFICATION REQUIRED IF THE LENGTH
DP1/2 # OF DELTA IS GREATER THAN .5 (8KM).
BMN CALL
INTGRATE
RECTIFY
INTGRATE SSP SSP # INITIALIZE INDICES AND SWITCHES
FBRANCH # EXIT FROM DIFEQCOM
CADR FBR3
HBRANCH # EXIT FROM KEPLER
CADR POSTRUE
CLEAR
JSWITCH # 1 FOR W MATRIX EXTRAPOLATE, 0 OTHERWISE.
DIFEQ0 VLOAD # POSITION DEVIATION INTO ALPHA
YV
STODL ALPHAV
DPZERO
STORE H # START H AT ZERO. GOES O(DELT/2)DELT.
STCALL DIFEQCNT # ZERO DIFEQCNT AND REGISTER FOLLOWING.
HBRANCH # GOES 0(-12D)(-24D).
## Page 792
# THE RECTIFY SUBROUTINE IS CALLED BY THE INTEGRATION PROGRAM AND OCCASIONALLY BY THE MEASUREMENT INCORPORATION
# ROUTINES TO ESTABLISH A NEW CONIC.
RECTIFY VLOAD VSR8 # RECTIFY - FORM TOTAL POSITION AND VEL.
TDELTAV # ADJUST SCALE DIFFERENCE (ASSUMED
VSR2 VAD # CONSTANT HERE.)
RCV
STORE RRECT
STOVL RCV # SET UP CONIC ,ANSWER, FOR TIMESTEP
TNUV
VSR8 VAD # SAME FOR VELOCITY.
VCV
STORE VRECT
AXT,1 SSP
12D # ZERO DELTA, NU, AND TIME SINCE RECT.
S1
2
STODL VCV
DPZERO
STORE TC
STORE XKEP # ZERO X.
ZEROLOOP STORE YV +12D,1 # INDICES CAUSE LOOP TO ZERO 6 CONSECUTIVE
STORE TDELTAV +12D,1 # DP NUMBERS (DELTA AND NU ARE ADJACENT).
TIX,1 ITCQ # LOOP OR START INTEGRATION STEP IF DONE.
ZEROLOOP
## Page 793
# THE THREE DIFEQ ROUTINES - DIFEQ+0, DIFEQ+12, AND DIFEQ+24 - ARE ENTEREDTO PROCESS THE CONTRIBUTIONS AT THE
# BEGINNING, MIDDLE, AND END OF THE TIMESTEP, RESPECTIVELY. THE UPDATING IS DONE BY THE NYSTROM METHOD.
DIFEQ+0 VLOAD VSR3
FV
STCALL PHIV
DIFEQCOM
DIFEQ+1 VLOAD VSR1
FV
PUSH VAD
PHIV
STOVL PSIV
VSR1 VAD
PHIV
STCALL PHIV
DIFEQCOM
DIFEQ+2 DLOAD DMPR
H
DP2/3
PUSH VXSC
PHIV
VSL1 VAD
ZV
VXSC VAD
H
YV
STOVL YV
FV
VSR3 VAD
PSIV
VXSC VSL1
VAD BOFF # SEE IF THIS IS STATE VECTOR OR W COLUMN.
ZV
JSWITCH
ENDSTATE
AXT,1
0
STORE W +72D,2 # VELOCITY COLUMN VECTOR
DLOAD
YV
STORE W +36D,2 # POSITION COLUMN VECTOR
TIX,2 GOTO # **********
NEXTCOL
STEPEXIT
## Page 794
NEXTCOL VLOAD* # SET UP NEXT COLUMNS OF W MATRIX
W +36D,2
STOVL* YV
W +72D,2
STCALL ZV
DIFEQ0
ENDSTATE STOVL TNUV
YV
STODL TDELTAV
H
SR4 SR2R
DAD
TC
STORE TC
BOFF AXT,2
WMATFLAG
STEPEXIT
36D
SSP AXT,1
S2
6
DOW..
SXA,1 SXA,1
FBRANCH
HBRANCH
INVERT AXT,1
JSWITCH
0
GOTO
NEXTCOL
## Page 795
# COMES HERE TO FINISH FIRST TWO DIFEQ COMPUTATIONS.
DIFEQCOM DLOAD DAD # INCREMENT H AND DIFEQCNT.
DT/2
H
INCR,1 SXA,1
DEC -12
DIFEQCNT # DIFEQCNT SET FOR NEXT ENTRY.
STORE H
VXSC VSR1
FV
VAD VXSC
ZV
H
VAD
YV
STCALL ALPHAV
FBRANCH
## Page 796
# ORBITAL ROUTINE FOR EXTRAPOLATION OF THE W MATRIX. IT COMPUTES THE SECOND DERIVATIVE OF EACH COLUMN POSITION
# VECTOR OF THE MATRIX AND CALLS THE NYSTROM INTEGRATION ROUTINES TO SOLVETHE DIFFERENTIAL EQUATIONS. THE PROGRAM
# USES A TABLE OF VEHICLE POSITION VECTORS COMPUTED DURING THE INTEGRATION OF THE VEHICLES POSITION AND VELOCITY.
DOW.. VLOAD VSR6
ALPHAV
PDVL* UNIT
VECTAB,1
PDVL VPROJ
ALPHAV
VXSC VSU
3/16
PDDL DMP
34D
36D
V/SC STADR
STCALL FV
NBRANCH
## Page 797
# CONSTANTS
KEPSILON OCT 00000
OCT 00002
THREE/8 2DEC .375
3/16 2DEC 3 B -4
DP1/4 2DEC .25
DP1/3 2DEC .333333333
DQUARTER EQUALS DP1/4
POS1/16 2DEC .0625
POS1/4 EQUALS DP1/4
3/8 EQUALS THREE/8
15/16 2DEC 15. B -4
3/4 2DEC 3.0 B -2
J2REQSQ 2DEC .335914874 # SECOND HARMONIC TIMES SQUARE OF RADIUS.
7/12 2DEC .5833333333
9/16 2DEC 9 B -4
5/128 2DEC 5 B -7
2J3RE/J2 2DEC -.003309146
J4REQ/J3 2DEC .60932709
DP1/2 2DEC .5
DPZERO 2DEC 0.0
DP2/3 2DEC .6666666667
2/3 EQUALS DP2/3
## Page 798
# DUMMYMOON POSITION ROUTINE, SUN POSITION ROUTINE, AND PBODY TABLE FOR CHECKOUT OF EARTH-ORBITAL ONLY.
MOONPOS VLOAD ITCQ # LOAD CONSTANT VECTOR INTO A AND EXIT.
MOONVEC
SUNPOS SETPD VLOAD # RETURNS WITH VECTOR IN VAC AND IN PDL.
0
SUNVEC
ITCQ
EARTHTAB DEC 6
2DEC 0.0
DEC 10
2DEC 0.0
2DEC 0.0
DEC -28 # 28 3/2
2DEC .6335627 # 400/SQRT(MU)
MOONVEC EQUALS EARTHTAB
SUNVEC EQUALS EARTHTAB +3 # ******
