ENTRY_LEXICON.agc
### FILE="Main.annotation"
## Copyright: Public domain.
## Filename: ENTRY_LEXICON.agc
## Purpose: Part of the source code for Artemis (i.e., Colossus 3),
## build 072. This is for the Command Module's (CM)
## Apollo Guidance Computer (AGC), for
## Apollo 15-17.
## 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/Artemis072/
## Mod history: 2009-08-11 JL Adapted from corresponding Comanche 055 file.
## 2010-02-20 RSB Un-##'d this header.
## 2017-01-22 RSB Proofed comment text by diff'ing vs Comanche 55
## and corrected errors found.
## Page 842
# 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 AGC ONLY
# 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 (FINAL PHASE TABLE) 805 FPSS NOT SAVED
# DVL VS1-VL 2 VSAT
# E ECCENTRICITY 4 NOT STORED
# F1( ) DRANGE/D DRAG (FINAL PHASE TABLE) 2700/805 = FX +5
# F2( ) DRANGE/D RDOT (FINAL PHASE TABLE) 2700/2VS NM/FPS = FX +4 /8
## Page 843
# F3( ) DRANGE/D (L/D) (FINAL PHASE TABLE) 2700 NM = FX
# * MAXIMUM VALUE DENOTES UNSCALED
# VARIABLE VALUE WHEN SCALED
# FIGURE 7.0-2 COMPUTER VARIABLES VARIABLE HAS MAXIMUM VALUE OF ONE.
## Page 844
# VARIABLE DESCRIPTION MAXIMUM VALUE COMPUTER NAME
# -------- ----------- ------- ----- -------- ----
#
# FACT1 CONST FOR UPCONTRL 2 VSAT
# FACT2 CONST FOR UPCONTRL 1/805 FPSS
# FACTOR USED IN UPCONTRL 1
# GAMMAL FLIGHT PATH ANGLE AT VL 1 RADIAN
# GAMMAL1 SIMPLE FORM OF GAMMAL 1 RADIAN
# 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
# LAT(SPL) GEODETIC LATITUDE OF TARGET 1 REVOLUTION
# LNG(SPL) LONGITUDE OF TARGET 1 REVOLUTION
# 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 21600 NM
# Q7 MINIMUM DRAG FOR UPCONTROL 805FPSS
# RDOT ALTITUDE RATE 2 VSAT
# RDOTREF REFERENCE RDOT FOR UPCONTROL 2 VSAT
# RDOTREF( ) REFERENCE RDOT (FINAL PHASE TABLE) 2 VSAT = FX +3 /8
# RDTR REFERENCE RDOT FOR DOWNCONT 2 VSAT NOT SAVED
# ROLLC ROLL COMMAND 1 REVOLUTION
# RTOGO( ) RANGE TO GO (FINAL PHASE TABLE) 2700 NM = FX +2
# SL SINE OF LATITUDE 1 NOT SAVED
# T TIME B 28 CENTISEC = PIPTIME-TIME/RTO
# 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
# VMAGI INERTIAL VELOCITY MAGNITUDE,|VI| 128 M/CENTISEC
# VREF REFERENCE VELOCITY FOR UPCONTROL 2 VSAT
# VREF( ) REFERENCE V (FINAL PHASE TABLE) 2 VSAT NOT STORED
# 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
## Page 845
# = WIE (DTEAROT)
# X INTERMEDIATE VARIABLE IN G-LIMITER 2 VSAT NOT SAVED
# Y LATERAL MISS LIMIT 4 RADIANS NOT SAVED
#
# FIGURE 7.0-2A COMPUTER VARIABLES (CONTINUED)
## Page 846
# 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 BRANCH (1) 95D, BIT10
# RELVELSW RELATIVE VELOCITY SWITCH NON-BRANCH (0) 96D, BIT 9
# EGSW FINAL PHASE SWITCH NON-BRANCH (0) 97D, BIT 8
# NOSWITCH INHIBIT LATERAL SWITCH 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 NON-BRANCH (0) 102D, BIT 3
#
# GONEBY INDICATES GONE PAST TARGET (SET) SELF-INITIALIZING 112D, BIT 8 IN STATE +7
#
# FIGURE 7.0-2B COMPUTER VARIABLES (CONTINUED)
## Page 847
# BODY ATTITUDE QUANTITIES (CM/POSE)
# -----------------------------------
#
# VARIABLE DECRIPTION 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
#
# FIGURE 7.0-2C COMPUTER VARIABLES (CONTINUED)
## Page 848
# DISPLAY QUANTITIES (FOR USAGE,SEE SECTION 4: P 61 THROUGH P 67)
# ------------------
#
# THIS TABLE PROVIDES THE READER WITH DISPLAY QUANTITY INFORMATION. THE VARIABLE NAMES REFLECT
# SECTION 5 USAGE. EXCEPTING IMBEDDED BLANKS, THE SECTION 4 NAMES ARE PARENTHESIZED,IF DIFFERENT.
# SIGN CONVENTIONS ARE FOUND IN SECTION 4. IF THE DISPLAY VARIABLE NAME DIFFERS FROM SECTION 5 USAGE,
# SAY BECAUSE OF SCALE FACTOR, THE ALTERNATE SECTION 5 NAME IS ENCLOSED IN ANGULAR BRACKETS: < >.
# DISPLAY QUANTITY INFORMATION APPEARING ELSEWHERE IN SECTION 5 OTHER THAN IN 5 7 MAY BE FOUND THUS:
# N 60 & N 63 (ALL) FIGURE 6.10-4 IN 5.6.10.3
# N 22 (ALL) FIGURE 6.10-11 IN 5.6.10.6
# N67 (LAT, LONG) FIGURE 5.3-1 IN 5.5.3
#
# VARIABLE DESCRIPTION MAXIMUM VALUE DISPLAY NOUNS
# -------- ----------- ------- ----- ------- -----
#
# GMAX 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.
# RTGO RANGE ANGLE TO SPLASH (RTOGO) 1 REVOLUTION N 63
# FROM 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 (TFE) TO B 28 CENTISEC N 63
# ALTITUDE EMSALT FT ABOVE FISCHER
# RADIUS.
# OGA OUTER GIMBAL ANGLE (OG ROLL) 1 REVOLUTION N 22
# IGA INNER GIMBAL ANGLE (IG PITCH) 1 REVOLUTION N 22
# MGA MIDDLE GIMBAL ANGLE (MG YAW) 1 REVOLUTION N 22
# ALL ABOVE ANGLES FOR HYPERSONIC TRIM
# D DRAG ACCELERATION (G) 805 FPSS N 64, N 74
# VMAGI INERTIAL VELOCITY MAGNITUDE (VI) 128 M/CENTISEC N 64, N 68, N 74
# ROLLC ROLL COMMAND (BETA) 1 REVOLUTION N 66, N 68, N 69, N 74
# XRNGERR CROSS-RANGE ERROR <LATANG IN NM> 1 REVOLUTION N 66
# DNRNGERR DOWN RANGE ERROR ** 1 REVOLUTION N 66
# <PREDANG - THETAH IN NM>
# ** <DNRNGERR DISPLAYS 9999.9 IF GONEPAST =1 IN P 67>
# HDOT ALTITUDE RATE <RDOT> 128 M/CENTISEC N 68
# Q7 EXIT DRAG LEVEL (DL) 805 FPSS N 69
# VL EXIT VELOCITY FOR UP-CONTROL 2 VSAT N 69
# RTOGO DESIRED RANGE ANGLE <THETAH> 1 REVOLUTION N 67, N 64
# <-THETAH IF GONEBY =0, THETAH IF GONEBY =1>
# LAT GEODETIC LATITUDE OF VEHICLE 1 REVOLUTION N 67
# LONG LONGITUDE OF VEHICLE 1 REVOLUTION N 67
#
# THE FOLLOWING IS A DATA INPUT NOUN (REFER TO SECTION 4,P 61 & P 62)
# HEADSUP INDICATOR FOR INITIAL ROLL 1 REVOLUTION N 61
# LAT(SPL) GEODETIC LATITUDE OF TARGET 1 REVOLUTION N 61
## Page 849
# (IMPACT LAT)
# LNG(SPL) LONGITUDE OF TARGET (IMPACT LONG) 1 REVOLUTION N 61
#
# FIGURE 7.0-2D COMPUTER VARIABLES (CONTINUED)
## Page 850
# CONSTANTS AND GAINS VALUE
# ------------------- -----
#
# C1 FACTOR IN ALP COMPUTATION 1.25
# C16 CONSTD GAIN ON DRAG 0.01
# C17 CONSTD GAIN ON RDOT 0.002
# C18 BIAS VEL. FOR FINAL PHASE START 500 FPS
# C20 MAX DRAG FOR DOWN-LIFT 210 FPSS
# C21 DRAG FOR NO LATERAL SWITCH 140 FPSS
# CHOOK FACTOR IN AHOOK COMPUTATION 0.25
# CH1 FACTOR IN GAMMAL COMPUTATION 1.0
# COS15 COS( 15 DEG) 0.965
# DLEWD0 INITIAL VARIATION IN LEWD -0.05
# 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 0.2 GS
# KA3 FACTOR IN D0 CALC 90 FPSS
# KA4 FACTOR IN D0 CALC 40 FPSS
# KB1 OPTIMIZED UPCONTROL GAIN 2.5
# KB2 OPTIMIZED UPCONTROL GAIN 0.0025
# KDMIN INCREMENT ON Q7F TO DETECT END OF KEPLER PHASE 0.5 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 0.41252961 NM
# LEWD1 NOMINAL UPCONTROL L/D 0.15
# POINT1 FACTOR TO REDUCE UPCONTROL GAIN 0.1
# Q3 FINAL PHASE DRANGE/D V 0.07 NM/FPS
# Q5 FINAL PHASE DRANGE/ D GAMMA 7050 NM/RAD
# Q6 FINAL PHASE INITIAL FLIGHT PATH ANGLE 0.0349 RAD
# Q7F MIN DRAG FOR UPCONTROL 6 FPSS
# Q7MIN MIN VALUE FOR Q7 IN FACTOR CALCULATION 805 FPSS (DISABLE FACTOR)
# Q19 FACTOR IN GAMMAL1 CALCULATION 0.5
# Q21 FACTOR IN Q2 CALCULATION. 3500 NM
# Q22 FACTOR IN Q2 CALCULATION. -1992 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 851
# 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 0.00162346
# 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 0.0000729211505 RAD/SEC
#
# FIGURE 7.0-3 CONSTANTS, GAINS AND CONVERSION FACTORS
