https://github.com/virtualagc/virtualagc
Revision 66d8e606a8d996ded60bc81d5edf319142a5fad9 authored by Ron Burkey on 04 October 2021, 11:49:55 UTC, committed by Ron Burkey on 04 October 2021, 11:49:55 UTC
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
ENTRY_LEXICON.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: ENTRY_LEXICON.agc
## Purpose: Part of the source code for Colossus build 237.
## This is for the Command Module's (CM) Apollo Guidance
## Computer (AGC), for Apollo 8.
## Assembler: yaYUL
## Contact: Jim Lawton <jim DOT lawton AT gmail DOT com>
## Website: www.ibiblio.org/apollo/index.html
## Page Scans: www.ibiblio.org/apollo/ScansForConversion/Colossus237/
## Mod history: 2011-03-02 JL Adapted from corresponding Colossus 249 file.
## 2017-01-01 RSB Proofed comment text using octopus/ProoferComments,
## and fixed errors found.
## 2017-01-08 RSB Fixed comment errors detected in cross-diff vs
## Colossus 249.
## 2017-01-22 RSB Back-ported comment error fixes detected in diff'ing
## Artemis 72 vs Comanche 55.
## Page 788
# VARIABLE DESCRIPTION MAXIMUM VALUE * COMPUTER NAME
# -------- ----------- ------- ----- -------- ----
# -
# URT0 INITIAL TARGET VECTOR 2 (UNIT VECTOR) = RTINIT
# -
# UZ UNIT VECTOR NORTH 1 = UNITW
# -
# V VELOCITY VECTOR 2 VSAT = VEL
# -
# R POSITION VECTOR 2 EXP 29 METERS = RN
# -
# VI INERTIAL VELOCITY 128 M/CENTISEC = VN
# -
# RTE VECTOR EAST AT INITIAL TARGET 2 = RTEAST
# -
# UTR NORMAL TO RTE AND UZ 2 = RTNORM
# -
# URT TARGET VECTOR 2 = RT
# -
# UNI UNIT NORMAL TO TRAJECTORY PLANE 2
# -
# DELV INTEGRATED ACCEL. FROM PIPAS 5.85 16384 CM/S
# -
# G GRAVITY VECTOR 128 M/CENTISEC = GDT/2
# A0 INITIAL DRAG FOR UPCONTRL 805 FPSS FPSS=FT/SEC/SEC
# AHOOKDV TERM IN GAMMAL CALC. = AHOOK DVL 8
# A1 DRAG VALUE IN FACTOR CALCULATION 805 FPSS
# ALP CONST FOR UPCONTRL 1
# ASKEP KEPLER RANGE 21600 NM NM = NAUTICAL MILE
# ASP1 FINAL PHASE RANGE 21600 NM
# ASPUP UP-RANGE 21600 NM
# ASP3 GAMMA CORRECTION 21600 NM
# ASPDWN RANGE DOWN TO PULL-UP 21600 NM
# ASP PREDICTED RANGE 21600 NM NOT STORED
# COSG COSINE(GAMMAL) 2 = COSG/2
# C/D0 RECIPROCAL DRAG, -4/D0 B-8 64/FPSS
# D TOTAL ACCELERATION 805 FPSS
# D0 CONTROLLED CONSTANT D 805 FPSS
# DHOOK TERM IN GAMMAL COMPUTATION 805 FPSS
# DIFF THETNM-ASP (RANGE DIFFERENCE) 21600 NM
# DIFFOLD PREVIOUS VALUE OF DIFF 21600 NM
# DLEWD CHANGE IN LEWD 1
# DR REFERENCE DRAG FOR DOWNCONTROL 805 FPSS NOT STORED
# DREFR REFERENCE DRAG 805 FPSS NOT STORED
# DVL VS1-VL 2 VSAT
# E ECCENTRICITY 4 NOT STORED
# F1 DRANGE/D DRAG (FINAL PHASE) 2700/805 = FX +5
# F2 DRANGE/D RDOT (FINAL PHASE) 2700/2VS NM/FPS = FX +4
## Page 789
# F3 DRANGE/D (L/D) 2700 NM = FX
# FACT1 CONST FOR UPCONTRL 805 FPSS
# FACT2 CONST FOR UPCONTRL 1/805 FPSS
# FACTOR USED IN UPCONTRL 1 * MAXIMUM VALUE DENOTES UNSCALED
# GAMMAL FLIGHT PATH ANGLE AT VL 1 RADIAN VARIABLE VALUE WHEN SCALED
# GAMMAL1 SIMPLE FORM OF GAMMAL 1 RADIAN VARIABLE HAS MAXIMUM VALUE OF ONE.
## Page 790
# VARIABLE DESCRIPTION MAXIMUM VALUE COMPUTER NAME
# -------- ----------- ------- ----- -------- ----
# HEADSUP INDICATOR FOR INITIAL ROLL 1
# KA DRAG TO LIFT UP IF DOWN 805 FPSS = KAT
# KLAT LATERAL SWITCH GAIN 1 (NOM = .0125)
# K2ROLL INDICATOR FOR ROLL SWITCH
# LAD MAX L/D (MIN ACTUAL VEHICLE L/D) 1
# LADPAD NOMINAL VEHICLE L/D, SP PAD LOAD 1 (NOM = 0.3)
# LATANG LATERAL RANGE 4 RADIANS
# LEQ EXCESS C.F. OVER GRAV=(VSQ-1)GS 128.8 FPSS
# LEWD UPCONTROL REFERENCE L/D 1
# LOD FINAL PHASE L/D 1 (NOM = 0.18)
# LODPAD FINAL PHASE L/D, SP PAD LOAD 1
# L/D DESIRED LIFT TO DRAG RATIO 1
# (VERTICAL PLANE)
# L/D1 TEMP STORAGE FOR L/D IN LATERAL 1
# L/DCMINR LAD COS(15DEG) 1 (NOM = 0.2895)
# PREDANGL PREDICTED RANGE (FINAL PHASE) 2700 NM = PREDANG
# Q2 FINAL PHASE RANGE -23500 Q3 21600 NM
# Q2 = FCN(LAD)
# Q7 MINIMUM DRAG FOR UPCONTROL 805 FPSS
# RDOT ALTITUDE RATE 2 VSAT
# RDOTREF REFERENCE RDOT FOR UPCONTROL 2 VSAT
# RDTR REFERENCE RDOT FOR DOWNCONT 2 VSAT NOT SAVED
# ROLLC ROLL COMMAND 1 REVOLUTION
# RTOGO RANGE TO GO (FINAL PHASE) 2700 NM = FX +2
# SL SINE OF LATITUDE 1 NOT SAVED
# T TIME B 28 CENTISEC = TIME2,TIME1
# THETA DESIRED RANGE (RADIANS) 2 PI RADIANS = THETAH
# THETNM DESIRED RANGE (NM) 21600 NM NON EXISTENT
# V VELOCITY MAGNITUDE 2 VSAT
# V1 INITIAL VELOCITY FOR UPCONTROL 2 VSAT
# VL EXIT VELOCITY FOR UPCONTROL 2 VSAT
# VREF REFERENCE VELOCITY FOR UPCONTROL 2 VSAT
# VS1 VSAT OR V1, WHICHEVER IS SMALLER 2 VSAT
# 2 2
# VBARS VL /VSAT 4
# 2 2
# VSQ NORMALISED VEL. SQUARED = V /VSAT 4 = VSQUARE
# WT EARTH RATE TIMES TIME 1 REVOLUTION NOT SAVED
# = WIE (DTEAROT)
# X INTERMEDIATE VARIABLE IN G-LIMITER 2 VSAT NOT SAVED
# Y LATERAL MISS LIMIT 4 RADIANS NOT SAVED
## Page 791
# EXTRA COMPUTER ERASABLE LOCATIONS NOT SHOWN ON FLOW CHARTS
# -----------------------------------------------------------
# VARIABLE DESCRIPTION MAXIMUM VALUE
# -------- ----------- ------- -----
# GOTOADDR ADDRESS SELECTED BY SEQUENCER
# XPIPBUF BUFFER TO STORE X PIPA COUNTS
# YPIPBUF BUFFER TO STORE Y PIPA COUNTS
# ZPIPBUF BUFFER TO STORE Z PIPA COUNTS
# PIPCTR COUNTS PASSES THRU PIPA READ ROUTINE
# JJ INDEX IN FINAL PHASE TABLE LOOK-UP
# MM INDEX IN FINAL PHASE TABLE LOOK-UP
# GRAD INTERPOLATION FACTOR IN FINAL PHASE
# FX DRANGE/D L/D = F3 2700 NM
# FX + 1 AREF 805 FPSS
# FX + 2 RTOGO 2700 NM
# FX + 3 RDOTREF VSAT/4
# FX + 4 DRANGE/D RDOT = F2 21600/2VS NM/FPS
# FX + 5 DRANGE/D DRAG = F1 2700/805 NM/FPSS
# TEM1B TEMPORARY LOCATION
# TIME/RTO TIME OF INITIAL TARGET RTINIT B 28 CENTISEC
# DTEAROT EST TIME BETWEEN RTINIT AND RT B 28 CENTISEC
# -
# UNITV UNIT V VECTOR 2
# -
# UNITR UNIT R VECTOR 2
# -
# -VREL NEGATIVE VELOCITY REL TO ATMOSP 2 VSAT
# COMPUTER SWITCHES INITIAL STATE CM/FLAGS = STATE +6
# -------- -------- ------------- -------------------
# ENTRYDSP DO ENTRY DISPLAY, IF SET NON-BRANCH (1) 92D, BIT13
# GONEPAST INDICATES OVERSHOOT OF TARGET NON-BRANCH (0) 95D, BIT10
# RELVELSW RELATIVE VELOCITY SWITCH NON-BRANCH (0) 96D, BIT 9
# EGSW FINAL PHASE SWITCH NON-BRANCH (0) 97D, BIT 8
# FIRSTPAS INITIAL PASS THRU HUNTEST NON-BRANCH (0) 98D, BIT 7
# HIND INDICATES ITERATION IN HUNTEST NON-BRANCH (0) 99D, BIT 6
# INRLSW INDICATES INIT ROLL ATTITUDE SET NON-BRANCH (0) 100D, BIT 5
# LATSW INHIBIT DOWNLIFT SWITCH IF NOT SET BRANCH (1) 101D, BIT 4
# .05GSW INDICATES DRAG EXCEEDS .05 GS BRANCH (0) 102D, BIT 3
# GONEBY INDICATES GONE PAST TARGET (SET) SELF-INITIALZNG 112D, BIT 8
## Page 792
# CONSTANTS AND GAINS VALUE
# ------------------- -----
# C1 FACTOR IN ALP COMPUTATION 1.25
# C16 CONSTD GAIN ON DRAG .01
# C17 CONSTD GAIN ON RDOT .001
# C18 BIAS VEL. FOR FINAL PHASE START 500 FPS
# C20 MAX DRAG FOR DOWN-LIFT 175 FPSS
# CHOOK FACTOR IN AHOOK COMPUTATION .25
# CH1 FACTOR IN GAMMAL COMPUTATION 1.0
# COS15 COS( 15 DEG) .965
# DLEWD0 INITIAL VARIATION IN LEWD -.05
# D2 DRAG TO CHANGE LEWD 175 FPSS
# DT COMPUTATION CYCLE TIME INTERVAL 2 SEC.
# GMAX MAXIMUM ACCELERATION 257.6 FPSS (8 G-S)
# KA1 FACTOR IN KA CALC 1.3 GS
# KA2 FACTOR IN KA CALC .2 GS
# KA3 FACTOR IN D0 CALC 90 FPSS
# KA4 FACTOR IN D0 CALC 40 FPSS
# KB1 OPTIMIZED UPCONTROL GAIN 3.4
# KB2 OPTIMIZED UPCONTROL GAIN .0034
# KDMIN INCREMENT ON Q7 TO DETECT END OF KEPLER PHASE .5 FPSS
# KTETA TIME OF FLIGHT CONSTANT 1000
# KLAT1 FACTOR IN KLAT CALC 1/24
# K44 GAIN USED IN INITIAL ROLL SECTION 19749550 FPS
# LATBIAS LATERAL SWITCH BIAS TERM .41252961 NM
# LEWD1 NOMINAL UPCONTROL L/D .15
# POINT1 FACTOR TO REDUCE UPCONTROL GAIN .1
# Q2 FINAL PHASE RANGE - 23500 Q3 -1002 NM
# Q3 FINAL PHASE DRANGE/D V .07 NM/FPS
# Q5 FINAL PHASE DRANGE/ D GAMMA 7050 NM/RAD
# Q6 FINAL PHASE INITIAL FLIGHT PATH ANGLE .0349 RAD
# Q7F MIN DRAG FOR UPCONTROL 6 FPSS
# Q7MIN MIN VALUE FOR Q7 IN FACTOR CALCULATION 40 FPSS
# Q19 FACTOR IN GAMMAL1 CALCULATION .5
# Q21 FACTOR IN Q2 CALCULATION. 1000 NM
# Q22 FACTOR IN Q2 CALCULATION. -1302 NM
# VFINAL1 VELOCITY TO START FINAL PHASE ON INITIAL ENTRY 27000 FPS
# VFINAL FACTOR IN INITIAL UP-DOWN CALC 26600 FPS
# VLMIN MINIMUM VL 18000 FPS
# VMIN VELOCITY TO SWITCH TO RELATIVE VEL VSAT/2
# VRCONTRL RDOT TO START INTO HUNTEST 700 FPS
# VRCONT = COMPUTER NAME
# 25NM TOLERANCE TO STOP RANGE ITERATION 25 NM
# VQUIT VELOCITY TO STOP STEERING 1000 FPS
## Page 793
# CONVERSION FACTORS AND SCALING CONSTANTS
# ---------- ------- --- ------- ---------
# ATK ANGLE IN RAD TO NM 3437.7468 NM/RAD
# GS NOMINAL G VALUE FOR SCALING 32.2 FPSS
# HS ATMOSPHERE SCALE HEIGHT 28500 FT
# J GRAVITY HARMONIC COEFFICIENT .00162346
# KWE EQUATORIAL EARTH RATE 1546.70168 FPS
# MUE EARTH GRAVITATIONAL CONSTANT 3.986032233 E 14 CUBIC M/ SEC SEC
# RE EARTH RADIUS 21202900 FT
# REQ EARTH EQUATORIAL RADIUS 20925738.2 FT
# VSAT SATELLITE VELOCITY AT RE 25766.1973 FPS
# WIE EARTH RATE .0000729211505 RAD/SEC
# (END GSOP AS-278, VOL 1, FIG. 5.6-3 CONSTANTS,GAINS, ETC.)
# DISPLAY QUANTITIES
# ------------------
# (SEE SECTION 4 OF THE GSOP FOR SIGN CONVENTIONS. )
# VARIABLE DESCRIPTION MAXIMUM VALUE
# -------- ----------- ------- -----
# QMAX PREDICTED MAXIMUM ENTRY ACCEL 163.84 GS N 60
# VPRED PREDICTED VELOCITY AT ALTITUDE 128 M/CENTISEC N 60
# 400K FT ABOVE FISCHER RADIUS.
# GAMMAEI PREDICTED GAMMA AT ALTITUDE 1 REVOLUTION N 60
# 400K FT ABOVE FISCHER RADIUS.
# D DRAG ACCELERATION 805 FPSS N 64
# VMAGI INERTIAL VELOCITY MAGNITUDE 128 M/CENTISEC N 64, N 68
# THETAH DESIRED RANGE ANGLE NM 1 REVOLUTION N 64, N 67
# LAT PRESENT LATITUDE 1 REVOLUTION N 67
# LONG PRESENT LONGITUDE 1 REVOLUTION N 67
# RTOGO RANGE ANGLE TO SPLASH FROM 1 REVOLUTION N 63
# EMSALT FT ABOVE FISCHER RADIUS. (IN NM)
# VIO PREDICTED VELOCITY AT ALTITUDE 128 M/CENTISEC N 63
# EMSALT FT ABOVE FISCHER RADIUS.
# TTE TIME OF FREE FALL TO ALT B 28 CENTISEC N 63
# EMSALT FT ABOVE FISCHER RADIUS.
# ROLLC ROLL COMMAND 1 REVOLUTION N 66, N 68, N 69
# LATANG CROSS-RANGE ERROR (XRNGERR) 4 RADIANS N 66
# DNRNGERR DOWN RANGE ERROR 1 REVOLUTION N 66
# (PREDANG - THETAH IN NM)
# HDOT ALTITUDE RATE 128 M/CENTISEC N 68
# Q7 MINIMUM DRAG FOR UPCONTROL 805 FPSS N 69
# VL EXIT VELOCITY FOR UP-CONTROL 2 VSAT N 69
## Page 794
# BODY ATTITUDE QUANTITIES (CM/POSE)
# -----------------------------------
# VARIABLE DESCRIPTION MAXIMUM VALUE
# -------- ----------- ------- -----
# -
# -VREL NEGATIVE VELOCITY REL TO ATMOS. 2 VSAT
# -
# OLDUYA USED FOR UYA BELOW 1000 FPS 2
# -
# UXA/2 UNIT VECTOR TRIAD 2
# -
# UYA/2 BASED ON 2
# -
# UZA/2 THE TRAJECTORY. 2
# -
# UBX/2 UNIT VECTOR 2
# -
# UBY/2 BODY TRIAD 2
# -
# UBZ/2 FOR CM. 2
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