Position Determination with Loran-C Triplets Using the HP-75C, the Sharp PC-1500 (TRS-80 PC-2) or the TRS-80 Model 100
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MONTEKE), CALIFORNIA 93940
NPS55-83-023
—S
AVAL POSTGRADUATE SCHOOL
Monterey, California
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POSITION DETERMINATION WITH LORAN-C
TRIPLETS USING THE HEWLETT-PACKARD HP-75C,
THE SHARP PC-1500 (TRS-80 PC-2) OR
THE RADIO SHACK TRS-80 MODEL 100
PORTABLE COMPUTERS
by
Rex H. Shudde
September 1983
FEDDOCS Approved for public release; distribution unlimited
D 208.14/2:NPS-55-83-023
.-vpared for:
Chief of Naval Res -rch
Arlington, VA 2221”
NAVAL POSTGRADUATE SCHOOL
Monterey, California
Rear Admiral J. J. Ekelund David A. Schrady
Superintendent Provost
This work was supported by the Office of Naval Research, Fleet Activity Support
Division, Code 238.
Reproduction of all or part of this report is authorized.
This report was prepared by:
UNCLASSIFIED
SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered)
REPORT DOCUMENTATION PAGE ee BE eae a4
1. REPORT NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT'S CATALOG NUMBER
NPS55-83-023
4. TITLE (end Subtitle) POSTTION DETERMINATION WITH LORAN-C | §. TYPE OF REPORT & PERIOD COVERED
TRIPLETS USING THE HEWLETT-PACKARD HP-75C, THE
SHARP PC-1500 (TRS-80 PC-2) OR THE RADIO SHACK a ae
TRS-80 MODEL 100 PORTABLE COMPUTERS 6. PERFORMING ORG. REPORT NUMBER
7. AU THOR(a) CONTRACT OR GRANT NUMBER(@)
Rex H. Shudde
3. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK
Naval Postgraduate School BRE AS SORKIUNUT NUMBERS
Monterey, CA 93943 65155N: RO131; NR 364-615
N0001483WR30112
11, CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE
Chief of Naval Research September 1983
Arlington, VA 22217 13. NUMBER OF PAGES
43
14” MONITORING AGENCY NAME & ADDRESS(If diiferent from Controlling Office) 18. SECURITY CLASS. (of thie report)
Unclassified
18a. DECLASSIFICATION/ DOWNGRADING
SCHEDULE
16. DISTRIBUTION STATEMENT (of this Report)
Approved for public release; distribution unlimited.
17. DISTRIBUTION STATEMENT (of the abstract entered In Block 20, If different from Report)
18. SUPPLEMENTARY NOTES
19. KEY WORDS (Continue on reverse side If necessary and Identify by block number)
Loran Hyperbolic Fixing Sharp
Loran-C Radio Positioning Hewlett-Packard
Navigation HP-75C Radio Shack
Position PC-1500
Fixing TRS-80 Model 100
20. ABSTRACT (Continue on reveree elde If neceseary and Identity by block number)
This report contains user instructions and program listings for a Loran-C
position determination algorithm for use on an Hewlett-Packard HP-75C, a
Sharp PC-1500 (Radio Shack TRS-80 PC-2) and a Radio Shack Model 100 portable
computers.
DD 628, 1473 evition oF 1 Nov 68 Is OBSOLETE
S/N 0102- LF- 014-6601
UNCLASSIFIED
SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered)
POSITION DETERMINATION WITH LORAN-C
TRIPLETS USING THE HEWLETT-PACKARD HP-75C,
THE SHARP PC-158@ (TRS-88@ PC-2) OR
THE RADIO SHACK TRS-88 MODEL 168
PORTABLE COMPUTERS.
by
Rex H. Shudde
Naval Postgraduate School
Monterey, California
September 1983
The programs in this report
are for use within the Navy,
and they are presented with-
out representation or warranty
of any kind.
I.
II.
III.
IV.
VI.
CONTENTS
Page
IMNCLOGUCEION cesesecscrsvsccceneevesscevresersrscvees 1
The Hewlett-Packard HP-75C ..ccceccercrcccccecccccccs 4
HP-75C User ImStructionS ..ecccsercccccvrccecvrvcecccce 4
HP-75C Sample ProblemS ..ccccccccccrcssvevccvescescece 6
HP-75C Program LiSting ......ccecceccrccrcccecceveveee 1G
The Sharp PC-15@@ (Radio Shack TRS-8@ PC-2) ......... 15
PC-1508 User InstructionS ......c.ceceecccceccsccecee 15
PC-1588 Sample ProblemS) .....cceerercccccccccccceecee 17
PC-1560 Program Listing ...cccccecerercccecccececesee 21
The Radio Shack TRS-8@ Model 106 .......eeeveecesesese 29
TRS-86 Model User InstructionS ....ececerevccceveveee 29
TRS-86 Model Sample ProblemS) .......cccccccecccvceeee 31
TRS- 88 Model Program Listing .....ccececcccccscveeees 35
Memory REquireMENtS ...ccecccecccccccrccccccccceceees 40
REFELENCES Lecce ccc cc cccccccccccccrcccccvcceseseccees 41
Appendix: Loran-C Station Data ..ccerceccecccceeceseee 42
ABSTRACT
This report contains user instructions and program listings
for a Loran-C position determination algorithm for use on an
Hewlett-Packard HP-75C, a Sharp PC-159@ (Radio Shack TRS-8@ PC-2)
and a Radio Shack Model 198 portable computers.
20
I. INTRODUCTION
This report contains a Loran-C position determination program
for each of the following portable computers: the Hewlett-Packard
HP~75C, the Sharp PC-158@8 (Radio Shack TRS-8@ PC-2) and the Radio
Shack) TRS-8@ Model 100. These programs are part of a set that has
been developed for a portable computer evaluation.
The Loran system is a radio aid to navigation which utilizes
the principle of hyperbolic fixing. The locus of points for which
the difference in arrival time of synchronized signals from a pair
of transmitters is constant determines a hyperbolic line of
positions. The intersection of two hyperbolic lines of position
from two pairs of stations determines a hyperbolic fix. That two
pairs of stations are required for a fix does not necessarily mean
that there are four separate stations, for one station of one pair
may be colocated with one station of the other pair forming a
Loran triplet. Triplets may be joined "end-to-end" by station
colocation to form a Loran chain. Loran chains are common on both
the East and West coasts of the North American continent.
The present day Loran-C operates at 1@8-kHz and is in use in
the Atlantic, Pacific and Mediterranean areas. The computational
programs described herein can be used for position determination
with Loran-C triplets. Further information on the history,
development and operation of the Loran systems may be found in
References 1 and 2. Details of the fixing algorithm can be found
in Reference 3.
In the programs presented here, there are ten user options.
The computer display abbreviations for the option names and their
definitions are listed below.
1.
LORAN FIX. This fixing routine is the main program for
calculating a LORAN-C fix from indicated time delays (ITDs).
ALTERNATE SOLN. The alternate solution routine will allow
the second LORAN-C fix solution to be computed. This routine
toggles an alternate solution flag so that on subsequent
fixes Option 1 will calculate the alternate solution.
INPUT DEST LAT/LONG. This option is used to store the
latitude and longitude of a destination.
HEAD & DIST TO DEST. This option is used to compute the
heading and distance from the currect fix to the destination
stored by Option 3.
PREDICT ITDs. This option may be used to predict the
station ITDs that will be received at a given latitude and
longitude.
TWO POINT HEAD & DIST. This option is similiar to Option 4
except that it may be used to compute the heading and
distance from any origin to any destination.
CALIBRATE. Given the latitude and longitude of a benchmark
position and the indicated time delays from a LORAN-C
triplet received at the benchmark position, the stored
station data are modified so that the fix routine (or
alternate solution routine) will compute the known position
from the same time delays.
8. NEW STA, IDs. This option is used to load the two station
pairs being received by requesting the group repetition
interval (GRI) identifier.
9. ASF Corrections. When a portion of the propagation path
lies over land, the additional secondary factor (ASF) should
be included in the observed time delay if precision
navigation is required. This option allows the user to input
the ASF correction [Ref. 4, 5].
A. STOP. This option will exit from the LORAN-C routine.
An additional HELP option (H) is available in the Hewlett-
Packard HP-75C and Sharp PC-158@ (TRS-8@ PC-2) computers. This
option will review the ten options in the display. The Radio Shack
TRS- 88 Model 108 does not have this option because all ten options
can be displayed simultaneously.
II. THE HEWLETT-PACKARD HP-75C.
HP-75C USER INSTRUCTIONS.
The options are labeled 1 through 9, A or H. The H (Help) option
will review options 1 - 9 & A. Option 6 (TWO POINT HEAD & DIST) is
a stand-alone option which may be used by itself. For LORAN
fixing, Option 8 must be selected first to load the station GRI's.
If Option 8 is not used, then any option requiring the GRI's will
automatically enter Option 8 first. Option 1 (LORAN FIX) must be
selected at least once before Option 2 (ALTERNATE SOLN) can be
selected. Once the GRI's are loaded, any of the remaining options
may be used at any time. When first run, the ASF Correction
Factors are set to zero; if they are subsequently entered as
non-zero values they will remain set until either changed
manually, by selection of Option 9, or until the program is RUN
once more. In all cases, South latitudes and East longitudes must
be negative for input and will be labeled by a minus sign '-' on
output. For ease of reference the options are listed by number
rather than by sequence of selection.
INSTRUCTION DISPLAY INPUT
Run Program Run "LORAN"
NEXT OPTION (Help) ?
1. LORAN FIX 1
ITD for lst GRI ITD FOR gril? lst ITD [RTN]
ITD for 2nd GRI ITD FOR gri 2? 2nd ITD [RTN]
Lat of fix LAT = dd°mm'ss" [RTN]
Long of fix LONG = ddd°mm'ss" [RTN]
NEXT OPTION (Help) ?
2. ALTERNATE SOLN 2
Lat of fix LAT = dd°mm'ss" [RTN]
Long of fix LONG = ddd°mm'ss" [RTN]
NEXT OPTION (Help) ?
3. INPUT DEST LAT/LONG 3
DEST LAT dd.mmss? Lat of dest.
[RTN]
DEST LONG ddd.mmss? Long of dest.
[RTN]
NEXT OPTION (Help) ?
4. HEAD & DIST TO DEST 4
Heading to dest. HEADING = dd°mm'ss" [RTN]
Dist. to dest. DISTANCE = mmm.ff n.mi. [RTN]
NEXT OPTION (Help) ?
HP-75C USER INSTRUCTIONS
INSTRUCTION DISPLAY
PREDICT ITDs
LAT dd.mmss?
LONG ddd.mmss?
lst ITD ITD FOR gri 1 =
XXXXX.XX HS
2nd ITD ITD FOR gri 2 =
XXXXX.XX US
New Lat/Lon or
Return to menu
NEXT OPTION (Help)?
TWO POINT HEAD & DIST
Heading to dest.
Dist. to dest.
CALIBRATE
NEW STA. IDs
ASF Corrections
STOP
ORIGIN LAT dd.mmss?
ORIGIN LONG ddd.mmss?
DEST LAT dd.mmss?
DEST LONG ddd.mmss?
HEADING = dd°mm'ss"”
DISTANCE = mmm.ff n.mi.
NEXT OPTION (Help)?
LAT dd.mmss?
LONG ddd.mmss?
ITD FOR gri 1?
ITD FOR gri 2?
NEXT OPTION (Help) ?
lst GRI?
2nd GRI?
NEXT OPTION (Help) ?
ASF FOR gri 1?
ASF FOR gri 2?
NEXT OPTION (Help) ?
(cont. )
INPUT
5
Lat [RTN]
Long [RTN]
{RTN]
[RTN]
N repeats Option 5
R goes to next line
6
Lat of origin
[RTN]
Long of origin
{RTN]
Lat of dest.
[RTN]
Long of dest.
[RTN]
[RTN]
[RTN]
7
Lat of fix [RTN]
Long of fix [RTN]
ist ITD [RTN]
2nd ITD [REN]
8
Sta. ID [REN]
Sta. ID [RTN]
9
lst ASF [RTN]
2nd ASF [RTN]
A
HP-75C SAMPLE PROBLEM 1
You are sailing off of the coast of California. Your
destination is Moss Landing at about 36°48'N and 121°47'W. Your
present ITD from station pair GRI 99408W is 16819 and your ITD from
station pair GRI 9946Y is 42585. What is your current position and
what is the heading and distance from your current position to
Moss Landing? We assume that the GRI's 994@W and 994@Y have not
yet been loaded.
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? 3 Input destination.
DEST LAT dd.mmss? 36.48 [RTN] 36°48!
DEST LONG ddd.mmss? 121.47 [RTN] 121°47'
NEXT OPTION (Help)? 8 Input station ID's,
ist GRI? 9940W [RTN]
2nd GRI? 9949Y [RTN]
NEXT OPTION (Help)? 1 Compute a fix.
ITD FOR 9940W? 16819
ITD FOR 9940Y? 42585
LAT = 39°14'19" [RTN] Latitude of fix.
LONG = 115°59'52" [RTN] Longitude of fix.
This fix is in Nevada. There are always two
solutions to the LORAN equations. The navigator
must select the correct one.
NEXT OPTION (Help)? 2 Select alternate soln.
LAT = 35°@@'@1" [RTN] Latitude of fix.
LONG = 125°@0'99" (RTN] Longitude of fix.
This fix is in the Pacific. The navigator
knows it is the correct fix because of his
estimate of where he should be.
NEXT OPTION (Help)? 4 Find heading & distance
to destination.
HEADING = 54°34'1]1" [RIN] Heading to Moss Landing.
DISTANCE = 198.38 n.mi. [RTN] Distance to Moss Landing.
NEXT OPTION (Help)? Repeat with new option
or press A to quit.
HP-75C SAMPLE PROBLEM 2
How far, and in what direction, is Corvallis, Oregon
(44° 34'N, 123°16'W) from Cupertino, California (37°19'N,
122° @2'W)?
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? 6 Two point distance
and heading.
ORIGIN LAT dd.mmss? 37.19 [RTN] 37°19'
ORIGIN LONG ddd.mmss? 122.02 [RTN] 122°62'
DEST LAT dd.mmss? 44.34 [RTN] 44°34'
DEST LONG ddd.mmss? 123.16 [RTN] 123°16'
HEADING = 353 62'59" [RTN]
DISTANCE = 438.32 n.mi. [RTN]
NEXT OPTION (Help)? Repeat with new option
Or press A to quit.
HP-75C SAMPLE PROBLEM 3
Suppose that you want to know what ITD's you would expect to
receive at 35° North, 125° West and at 36°27' North, 126°54' West
from 9946W and 9948Y. To determine these ITD's, proceed as follows
(assume that the GRI's have been loaded as in Sample Problem 1):
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? 5 Predict ITD's.
LAT dd.mmss? 35 [RTN] 35°
LONG ddd.mmss? 125 [RTN] 125°
ITD FOR 9940W = 16919.35 us [RTN]
ITD FOR 9948Y = 42584,71 us [RTN]
New Lat/Lon or
Return to menu? N
LAT dd.mmss? 36.27 [RTN] 36° 27!
LONG ddd.mmss? 126.54 [RTN] 126°54'
ITD FOR 9948W = 15572.32 ys [RTN]
ITD FOR 9940Y = 43006.15 us [RTN]
New Lat/Lon or
Return to menu? R
NEXT OPTION (Help)? Repeat with new option
or press A to quit.
HP-75C SAMPLE PROBLEM 4
Suppose you are receiving an ITD of 16388 from 9946W and
42800 from 9940Y. These ITD's would tell you that your location is
36°47'55"N and 121°47'11"W. However, you know that your position
is benchmarked to be at 36°47'36"N and 121°46'58"W, and you wish
to calibrate your HP-75C so that the ITD's of 16388 and 42808 will
give you the latter fix instead of the former. Proceed as follows
(assume the GRI's have been loaded as in Sample Problem 1):
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? 7 Calibrate.
LAT dd.mmss? 36.4736 [RTN] 36°47'36"
LONG ddd.mmss? 121.4658 [RTN] 121°45'58"
ITD FOR 9946W? 16398 [RTN]
ITD FOR 9940Y? 42808 ([RTN]
The station baselines have now been modified to
achieve calibration. Now, reenter 16838 and 42808 into
the fixing routine to test the calibration. Calibration
does not modify the permanent station data stored in the
HP-75C. The calibration remains effective until the
GRI's are reloaded by Option 8. NOTE: The affect of
calibration on the accuracy of fixes far removed from
the benchmark has not been studied. The user should use
the calibration option with caution.
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? 1 Compute a fix.
ITD FOR 9946W? 16308 [RTN]
ITD FOR 9940Y? 42880 [RTN]
LAT = 36°47'35" {RTN] Lat of fix.
LONG = 121° 46'59" (RTN] Long of fix.
The small discrepancy between this fix and the
benchmark is due to assumptions in the fixing algorithm.
If higher precision is required, the ASF Correction
factor may be used (see Sample Problem 5). Note that you
may need to use the Alternate Solution Option 2 if the
fix obtained above is near 38°52'57"N and 116°51'1ll'w.
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? Repeat with new option
or press A to quit.
HP-75C SAMPLE PROBLEM 5
Suppose you are receiving an ITD of 12153.31 microseconds
from 9968W and 44451.83 microseconds from 9969Y. These ITD's would
tell you that your location is 44°15'@5"N and 67°25'23"W. Entering
the ASF Correction Tables [Ref. 5,6] with these readings, the ASF
Correction for GRI 9960W at 44°15'N and 67°25'W is 1.5 micro-
seconds. Similiarly, the ASF Correction for GRI 9960Y at these
coordinates is 2.7 microseconds. Enter these corrections into your
HP-75C and recompute your position. (Load the GRI's 9960W and
9968Y using Option 8).
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? 9 ASF Correction.
ASF FOR 9969W? 1.5 [RTN]
ASF FOR 9968Y? 2.7 [RTN]
NEXT OPTION (Help)? 1 Compute a fix.
ITD FOR 9960W? 12153.31 [RTN]
ITD FOR 9948Y? 44451.83 [RTN]
LAT = 44°15'26" [RTN]
LONG = 67°26'26" [RTN]
NEXT OPTION (Help)? Repeat with new option
or press A to quit.
These ASF Corrections have been entered into the
computer. The range of their validity must be checked
with the ASF Correction tables and reentered if they
change. NOTE: If you are using the ASF Correction Tables
and if you wish to calibrate to a benchmark position,
you should first enter the ASF Corrections for your
benchmark and then use the calibration Option 7 (see
Sample Problem 4).
HP-75C PROGRAM
18 REY LORAK-2 ROUTINE,
rev A?-A8-82, 1336 HOURS
2@ NO=15 @ REM NO=8 OF ¥
ASTER STATIONS
3@ OPTION ANGLE RATT ANS
@ OPTION BASE |
48 DEF FNRCX.M) =
X45) 74
5@ CH=1/298.26 & Au=-1
Cig=""
64 DEF FNP(T) = 129, 8425
O/T-, 4B758+, BAHD4D 70439"
T
70 DEF FNOCT) =
O/T- ALL4AZ+ ABBIZF 74624
aT
82 DISP # COTE 128
9 CS=KEYS W OIF C$="° Th
ER 96
1A CH=UPROS(CS) & FOF ©
=1 TG LENCCAS) @ IF C$=0
@S(C.C] THEN DISP & FETL
PK
118 NEXT C @ GOTO 98
128 DISP “WEXT OPTION ¢°
ACHRE( 284); 'elp)?* & CAF
='123456789AH" &@ GASHIE &
&
138 ON C GOSIIR 916,958, 1
G18, 1846, 1096, 996, 1208. |
96,1358.528,148 @ GOTO }
2h
140 TISP ‘1 - LORAN FIX"
@ DISP *2 - ALTERNATE $
GLK’ @ DISP ‘3 - INPUT B
EST LAT/LONG:
15@ DISP ‘4 - HEAD & DIS
T TO BEST’ @ DISP “5 - P
REDICT ITDs*
16@ DISP ‘6 - TWO POINT
HEAD & DIST’ @ DISP '7 -
CALIBRATE:
17@ DISP ‘8 - NEW STA.
Ds' @ DISP *9 - ASF Corr
ections' @ DISP ‘A - STQ
Pp
TWT (Me
-1@-
LISTING
188 RETURK
182 REM O°T 8
185 TF G1$¢3** THEN RETI
RH
198 FA=1 @ N=t @ INPUT °
ist GRI? *iT$
288 GOSUR 384 @ COSIIE 29
8 @ IF FA=2 THEN 198
218 FA=] & W=2 @ INPUT °
2nd GRI? °; I$ @ GOQSUB 3
£6
228 IF AS=19$ THEN GOSUE
478 ELSE 242
238 TF F@=1 THER 2b
248 GOSUE 394 & IF Fé=2
THEN 218
250 Fi=t @ Fo=1 @ IF GIS
=G2$ THEN Ine
260 TF PCL. PVSPC1.2) ANE
LOL. f=L01.2) THER 218
278 F2=-1 @ TF PCL} )=PL
2,2) GRE LOL P)=L02.2) TF
HEN 218
QRH Fi=-] @ TF (2,1 )=Pi
2.2) AND LOZ, P=aLG2) T
HER 214
298 F2=) @ TF PCO, 3=Pct
2) GWE LOZ. Sled. 2) TH
EH 318
3@R ISP -E. NO TRIPLET
“;G18-" & °:628 @ GASUB
1276 @ GOTO 198
318 FOR T=! TR 2 @ PL=Pé
1-1) @ LEELA. TD) @ P2=PC
2.1) @ L2=L(2,1)
328 DISP @ GOSUB 33 @ K
EXT 1 ® GC1)=@ @ C(2)=8
@ RETURN
338 GOSUB 658 @ B(I)=Sh
@ 201, P=21 @ 2(2, 1 =22
348 T=21282. 3593450
35@ IF 1>=537 THEN P=FHP
(7)
368 IF 1453? THEN P=FNOC
Tr)
TPA T(T)=T+P &@ RETURN
HP-75C PROGRAM LISTING (cont.)
3B@ L=LENC I$) @ AS=IEE1,
L-1] @ BS=I$(L.L) @ B=NU
WCBS) @ BS=CHRS(B-324(B>
SAY) @ RETURN
398 Ne=1 @ RESTORE
488 READ 19$,N@,P4,LA #
Wee"
418 FOR I=1 TO N@ @ PEAL
WAS, BOCTD PICT) LICL? &
WS=HSEKAS A NEXT J
428 JF 19$#A$ THEN 458
43A GOSIIE 474 @ IF Fa=2
THEN 468
44@ RETUPRK
450 WR=H2+] & IF NG’ =NG
THEN 464
46@ RISP 1$,° 1S NOT CAT
ALOCED* @ Fa=2 @ GOSIIE {
37A B® PRETLIPK
47@ FOP J=1 TO NO @ IF ke
$CT,J)=B4 THEN 496
488 HEXT J & FA=2 @ PETII
OH
49A JF N=} THER Ci$=1¢
S@A JF H=2 THER G2$=1$
SIR NCM=N9CT) & PLY NY=
FMACRADCFHH(PAY)) & LL.
WO=RADCFHH(LAY)
S2@ PC2,N=FHACRADCFHH IP
1€7)))) @ L¢2.ND=RADCFHH
(LACT) @ RETURN
538 DISP @ PUT CHRS$/13)
@ END
S48 REM DIR SOLN
558 Z28=SIN(71) @ 29=C0S(
21) @ PR=SINCPI) @ P9=CA
S(P1) @ H=-28eP9 @ C1=CA
Hh @ CO=CAe(1—Meh) 74
568 B=(1-C2)e(1-C2-C lee)
@ PoC2eC14lt4n72)/1 @H
=P9829
578 SISANGLE(P8,N) @ DA=
SB/D @ U=2*(SI-DB) @ W=l
~2ePeCOS(U) @ V=COS(U+DA
)
ovis
SRR X=C2*C 28ST N(DE) eCOSe
Bae (PeleV-1)) @ Y=2eP ale
WaSIN(BR)
S9A S2=DG+tX-Y @ SB=SINCS
2) @ S9=COS(S2) @ K=SORC
Betts (HeSO-PR4S8 42)
6BA P2=ATN( (PRESO+NeS8 34
yy
618 S3=AHGLE(P9"S9-PEeSe
#29, -SB#28)
62A H=Cte({-C2)*S2-C tal?
¥SReC0S(S14S1-S2) @ L2=L
1+S3-H
638 Z2=ANGLE!-(HeS9-PReS
&).-M) @ PETHRN
640 REM REVERSE SOLH
658 L3=L2-L1 @ P3=(P2-P!
72 @ PA=(PL4P2972
66 PE=SIN(PZ) @ PP=CHSC
PZ) @ PR=SIN(Pd) & PO=Ch
SCRA
6708 H=P7#P7-PRaePg & L=P5
ePGtHASTN(L2723*2 & faa?
#ASIN(SOP(L))
GBA U=2ePRePheP7eP7 7 (1-1
) @ V=2eP6ePEaP9eP9/| &
X=U+¥ @ Y=U-V @ T=Ra/SIK
CRA) ® fiadeTeT
690 E=2eCOS(RA) @ A=Nee
@ C=7-(A-E)72 @ HI=Ke(A+
Cey) @ B=R+h @ H2=YaCB+E
s¥) @ N3=faxey
7A W2=CHsCRe (NI -H2+H297
64 @ Bl=CAe(TexX-y)/4 & S
@=(T-D1+B2)*STN(DB)
TIB M=Z2eT-(2A8T-A)eK- (8
+4yaY
72R FaY+¥-Ee(4-%) @ G=CA
#(T/2+CG4N/64) @ Q=-Fahe
TAR(L3) 74
730 L4=(L3+0)72 @ LR=SIN
(L4) ® LO=COS(L4)
748 TI=ANGLE(P9*L8, P6#L9
) @ T2=AHGLE(PS*L 8, -P7eL
9)
HP-75C PROGRAM LISTING (cont.)
75@ TS=PI4P] @ Zt=MORCTI
472,79) @ Z2=MOD(TI-T2.T
9) @ RETURN
768 REM FIXING ROUTINE
77@ AI=FI4SIN(ACL)) @ BI
=COS(ACL) -COS(BC1)) @ CT
f=SIN(BC1))
TBA AZ=F2eSTN(AC2)) @ BZ
=COS(A(2)-COS(B(2)) @ C
2=SIN(B(2))
798 E1=2¢1,1) @ IF Fl=-1
THEN Ei=2(2.1)
eae E2=2(1,2) @ IF F2=-1
THEN E2=2(2.2)
B18 C=B1eC2eC0S(E2)-B2sC
1eCOSCEL) @ S=BleC2eS TNC
£2)-B2eCisSIN(EL)
820 K=B2eA1-R1eA2 @ P=Se
R(CeC+SeS) @ G=ANGLECC.S
)
830 Z=G+ABSALNS(K/R) & SS
B=PNCLE(C2eC0S(2-E2 +A.
B2)
848 IF F2=1 THEN Pi=Pi1.
2) @ LIFL(1.2)
85@ IF F2=-1 THEN Pi=P(?
12) @ LI=L(2.2)
B68 21=Z # GOSUE Soh @ F
B=P2 & L@=L2 @ P=ATK¢TAK
(PA)/(1-€8))
878 P=BEGCP) @ L=MODCDEG
(L8),360) @ IF L518 THE
W L=L-368
RBA PS=FANS(P) @ LE=FADS
(Ld
898 DISP “LAT = “iP$ @G
OSUB 1378 @ DISP “LONG =
“iL$ @ GOSUB 1378 @ RET
URH
988 REM OPT 1 - COMPUTE
FIX
91@ GOSUR 185 @ FOR [=1
TO 2 @ G$=G1$ @ IF [=2 T
HEN G$=62$
-]2-
920 DISP “ITD FOR “Gs:
@ THPUT -? -; A @ A=A+E¢
T)-BCD-TC1) @ TF ABS(AY
<TC1) THEN 944
938 BISP -E. ITD HOT YAL
ID FOR ;G$ @ GOTO 928
940 ACTY=A721295. 8796 &
WEXT | @ GOSUB 778 @ PET
URN
95@ IF A@=1 THEN Aa=-1 &
GOTO 965
968 AB=1
965 IF Gi$="* THEN 916
978 GASUE 778 @ RETURN
980 REM AFT 6
998 INPUT “ORIGIN LAT de
camss? *; P @ THPUT *ORT
GIN LONG ddd.aass? “GL
JORG PR=FNACRAN(FNHCP) +)
@ LA=RADSFNH(L)) @ GOSH
B 1610 @ GQSUR 1644 & PE
TURK
1A1@ IMPLI “DEST LAT dd.
pass? "i P @ TRPUT “DEST
LONG ddd.anss? “GL
1828 PS=FMACRADCFNH(P)) >
@ LS=RARCFNH(L)) @ PETU
RN
1826 REM MPT 4
1048 P1=P@ @ LI=L@ &@ P2=
PS @ L2=L5 @ GQSUB 658
1656 Z2=MODCDEG(21), 368)
@ 2$=FNDS(Z)
1868 BISP “HEARING = -:2
$ @ GOSUB 1378 @ DISP “fh
ISTARCE = *;FWR(3443.917
#S0,188)i" nmi.”
1678 COSUB 1378 @ RETURN
1686 REM OPT 5
1698 COSUB 185 @ GOSUR 1
174 @ FOR K=1 10 2 @ I9=
TURD ADK)
1108 P2=P(2,K) @ L2=L(2.
kK) @ GOSUB 658 @ I=3 @ &
OSUB 340 @ 19=194+T(3)
HP-75C PROGRAM LISTING
111 P2=PCL,K) @ L2=L(t,
K) @ GOSUR 658 @ I-2 6G
OSUB 346 @ 19=19-T(3)
1128 [$=G1$ @ IF K=2 THE
W 1$=G2$
113 DISP “ITD FOR -s If:
= =°FFARCT9, 108) CHRS(12
divs” @ GOQSUB 1376 @ NEY
TK
1148 DISP CHP$(286): "eu
Lat/Lon or *:CHRE(Z1A):°
eturn to menu?” @ CAf="K
Pe @ GOSUE 98
1156 IF C=1 THEN 1a9H
1168 RETURN
1176 INPUT “LAT dd.anse?
°; PL @ INPHT LONG dda
eAAss? ML
118B PL=FNACRANCFRHSP SY)
> @ LISRADCFHH(L1)) @ PE
TUPH
$19@ PEM GPT 7
1288 GOSUB 125 @ GASHE t
178 @ FOR K=! 10 2 @ [$=
G1 @ TF K=2 THEN [$=G2$
1216 DISP “ITD FOR -s I$.
@ INPUT °2 °. 19 @ [9=]
O- ACK
1228 P2=P(2,K) @ L2=L(z,
¥) @ COSUB 658 @ [=2 #6
OSUB 348 @ 19=19-T(3)
1236 P2=PC1,%) @ L2=LC1.
K) @ GOSUB 658 @ 1-3 46
OSB 348 @ T(KI=194T(3)+
GK)
1248 HEXT K @ RETURN
1258 BEF FHH(X)
1268 S=SGH(X) ® X=ABS(X)
@ H=INT(X) @ V=FP(X) #10
@ @ FWH=S#( (16A8FP(V)/68
+ INT CY) 468+)
1278 EWR BEF
1288 DEF FRACX) = ATNOCL
-CA)*TANCX))
129 DEF FHDS(X)
-13-
(cont.)
1380 $=" - @ IF XC@ THE
H C$="-"
1318 X=ABS(K)41/7208 & ¥
@=INT(X) @ CS=CHRSTRSCHA
DECHRS(1)
1328 X=609(X-¥8) @ XASIN
TCX) @ XS=STREC1OG+KR) &
CS=CSEXST2, Z]E °°
1338 X=6ee(X-KAY @ KA=TH
TCX) B XS=STRS(1OG+KB)
FHDS=C$RX$(2. TIRCHPS (34
:)
1348 END DEF
1354 GOSHE 185 @ DISP *G
SF FOR ":C1$: @ INPUT °°
SLY
1366 DISP “ASF FOR ee
, RINPUT 25 GCE 8
ETURK
1370 C$=KEYE @ IF Cs=°
THEN 1374
1386 DISP @ PETURN
5088 BATA 4990,2, 16, 4442
95,169. 38412, -¥", 11886. 2
@.144916,155. 53897
5A18 DATA “Y", 29808. 28.2
3417? 178,17302
5828 DATA 5938,2,46, 4827
199,67. 5537712.7¥", 11066
,41.151193, 69, 583989
5830 BATA “Y",25080.46.4
63218,53. 182816
5048 PATA 5978,3,36.1105
797,-129. 2827279, "Wr 118
8,42. 4437184. -143. 43852
45
5658 DATA “¥-, 31600, 35.4
223871 .-126.3226741,°2°,
42890, 26. 3624975, -128.88
56445
5666 DATA 5998,3,51.575
78, 122. 228224, 7%" 11808,
55. 2628851, 131. 1519648
5876 BATA -Y-,27808,47.8
34799. 119.443953,°2°, 416
8,58. 3629731, 127.212904
3
HP-75C PROGRAM LISTING
5988 DATA 7928,3,59.5917
27:45, 182747. °W" 11088.6
4.542658, 23. 592179
5898 DATA °X",21088,62.!
75964, 7.0426538,°2° 4388
8.46. 46321893. 182816
5160 BATA 7#7928°,3,24.1
7B7888 - 153. 5893252. °X"-
11008,42,4437184,-142.42
a9245
5118 DATA “Y~, 38808. 26.3
624975, -128. @896445,°2°-
49008, 9. 3245789,-138.495
497
5128 BATA 7968.2.63, 1942
814,142. 48319. °X"- 11884.
57, 262821, 1592. 2211225
5138 DATA -¥*,26806,55.2
62RB51, 131. 1519648
5148 BATA 7978,4,62.1759
64.7.0426538, “WH”, 26884, 5
44829872 .-8. 1736312
S158 BATA “X~.11688,68.3
BBE1S,- 14.2747. °7° 46888
764.542658,23. 552175
5168 DATA -2- 68088. 76.5
49261,8. 435869
5178 BATA 7988.4, 38.5935
74,85, 1@@9385 .°W", 11888.
38. 4333818, 98. 49436
5186 BATA °X°,23888,26.3
155886 ,97. SBBAR93, “Y", 42
088, 27..8158393,88. 865342
9
5198 BATA °Z°, 59888, 34.4
346081577. 5446654
5288 PATA 7998,3, 38.5228
587,-16. 4306199, “K", 1168
8,35. 3128787,-12. 3138245
5218 BATA -Y",29880,48.5
82895 ,,-27.528152,°Z" 478
08, 42.8336515,-3. 1215512
=a
(cont. )
5228 BATA #978. 3,39.5187
54,87. 291214, -W", 11088, 2
8.593874, 85. 1889385
5238 BATA ~X- 26800: 42.4
250683, 76. 4953862, “9°, 44
OBB, 48. 364984494. 331846
9
5248 BATA 9948.3, 39, 7306
621,118. 495637
5258 BATA “W".11080.47.6
34799, 119. 443955, °X" 276
8B, 38. 465699, 122. 2944529
5268 DATA -Y° 48086, 35.1
91818, 114. 4817435
5278 DATA 9968.4,42.4258
683, 76.4933862."W", 11008
146.4827199,67, 5957713
S288 BATA *X-,25006, 41.1
51193, 69. 5839R9, “Y> . 2988
8,24, 0346081. 77. 5446604
5298 BATA °2°,54088, 39.5
18754.87.291214
53@@ BATA 9970,4,24, 4803
597-141. 1930383, "WH". 116
88,24. 1787888, -153. 58532
22
S318 BATA °X", 30800.42.4
437104. -143, 4309245. °¥";
S9C8» 26. 3624975,-128,.88
56445
5328 BATA °2°. 75888,9,32
45789.-138. 895497
5338 BATA 9998,3,57.8912
265,178. 1506789, “X" 1168
8,52. 494404 ,-173. 1648974
5348 BATA “Y°,29886,65.1
448386, 166.931295,°2°,43
008,57. 262821, 152.221122
B)
III.
THE SHARP PC-158% (RADIO SHACK TRS-8@ PC-2).
PC-15998 (TRS-8% PC-2) USER INSTRUCTIONS.
The options are labeled 1 through 9, A or H. The H (Help)
option will review options 1 - 9 & A. To step through the HELP
menu, use the ENTER key. Option 6 (TWO POINT HEAD & DIST) is a
stand-alone option which may be used by itself. For
Option 8 must be selected first to load the station GRI's.
LORAN fixing,
If
Option 8 is not used, then any option requiring the GRI's will
automatically enter Option 8 first.
selected at least once
before Option 2
Option 1 (LORAN
(ALTERNATE SOLN) can be
FIX) must be
selected. Once the GRI's are loaded, any of the remaining options
may be used at any time. When first run,
Factors are set to zero;
the ASF Correction
if they are subsequently entered as
non-zero values they will remain set until either changed
manually, by selection of Option 9, or until the program is RUN
once more,
be negative for input and will be labeled by a minus sign
In all cases, South latitudes and East longitudes must
poy
on
output. For ease of reference the options are listed by number
rather than by sequence of selection.
INSTRUCTION
Run Program
1. LORAN FIX
ITD for lst GRI
ITD for 2nd GRI
Lat of fix
Long of fix
ALTERNATE SOLN
Lat of fix
Long of fix
3. INPUT DEST LAT/LONG
HEAD & DIST TO DEST
Heading to dest.
Dist. to dest.
DISPLAY
NEXT OPTION (Help)?
ITD FOR gri 1?
ITD FOR gri 2?
LAT = ddemm'ss"
LONG = dddemm'ss"
NEXT OPTION (Help)?
LAT = dd°mm'ss"
LONG = dddemm'ss"
NEXT OPTION (Help)?
DEST LAT dd.mmss?
DEST LONG ddd.mmss?
NEXT OPTION (Help) ?
HEADING = ddemm'ss"
DISTANCE =
NEXT OPTION (Help) ?
-15-
mmm.ff n.
mi.
INPUT
RUN.198
i
lst ITD [ENTER]
2nd ITD [ENTER]
[ENTER]
[ENTER]
2
[ENTER]
[ENTER]
3
Lat of dest.
[ENTER]
Long of dest.
[ENTER]
4
[ENTER]
[ENTER]
PC-1598 (TRS-8@8 PC-2) USER INSTRUCTIONS (cont.)
INSTRUCTION
PREDICT ITDs
lst ITD
2nd ITD
DISPLAY
LAT dd.mmss?
LONG ddd.mmss?
ITD FOR gril =
XXXXX-XxX US
ITD FOR gri 2 =
XXXXX.XX US
New Lat/Lon or
Return to menu
NEXT OPTION (Help) ?
TWO POINT HEAD & DIST
Heading to dest.
Dist. to dest.
CALIBRATE
NEW STA. IDs
ASF Corrections
STOP
ORIGIN LAT dd.mmss?
ORIGIN LONG ddd.mmss?
DEST LAT dd.mmss?
DEST LONG ddd.mmss?
HEADING = dd°mm'ss"
DISTANCE = mmm.ff n.mi.
NEXT OPTION (Help) ?
LAT dd.mmss?
LONG ddd.mmss?
ITD FOR gri 1?
ITD FOR gri 2?
NEXT OPTION (Help) ?
lst GRI?
2nd GRI?
NEXT OPTION (Help) ?
ASF FOR gri 1?
ASF FOR gri 2?
NEXT OPTION (Help) ?
-1lfK—
INPUT
5
Lat [ENTER]
Long [ENTER]
[ENTER]
[ENTER]
N repeats Option 5
R goes to next line
6
Lat of origin
[ENTER]
Long of origin
[ENTER]
Lat of dest.
[ENTER]
Long of dest.
[ENTER]
[ENTER]
[ENTER]
7
Lat of fix [ENTER]
Long of fix [ENTER]
lst ITD [ENTER]
2nd ITD [ENTER]
8
ID [ENTER]
ID [ENTER]
Sta.
Sta.
9
lst ASF [ENTER]
2nd ASF [ENTER]
PC-1588 (TRS-8@ PC-2) SAMPLE PROBLEM 1
You are sailing off of the coast of California. Your
destination is Moss Landing at about 36°48'N and 121°47'W. Your
present ITD from station pair GRI 9940W is 16919 and your ITD from
station pair GRI 9946Y is 42585. What is your current position and
what is the heading and distance from your current position to
Moss Landing? We assume that the GRI's 9940W and 9948Y have not
yet been loaded.
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help) ? 3 Input destination.
DEST LAT dd.mmss? 36.48 [ENTER] 36°48!
DEST LONG ddd.mmss? 121.47 [ENTER] 121°47'
NEXT OPTION (Help)? 8 Input station ID's.
lst GRI? 9940W [ENTER]
2nd GRI? 994GY [ENTER]
NEXT OPTION (Help)? 1 Compute a fix.
ITD FOR 9946W? 16819
ITD FOR 9946Y? 42585
LAT = 39 14 19 [ENTER] Latitude of fix.
LONG = 115 58 52 [ENTER ] Longitude of fix.
This fix is in Nevada. There are always two
solutions to the LORAN equations. The navigator
must select the correct one.
NEXT OPTION (Help)? 2 Select alternate soln.
LAT = 35 @@ @1 [ENTER] Latitude of fix.
LONG = 125 @8@ @9 [ENTER] Longitude of fix.
This fix is in the Pacific. The navigator
knows it is the correct fix because of his
estimate of where he should be.
NEXT OPTION (Help)? 4 Find heading & distance
to destination.
HEADING = 54 34 ll {ENTER] Heading to Moss Landing.
DISTANCE = 198.38 n.mi. [ENTER] Distance to Moss Landing.
NEXT OPTION (Help) ? Repeat with new option
or press A to quit.
-l17-
PC-1598 (TRS-88 PC-~2) SAMPLE PROBLEM 2
How far, and in what direction, is Corvallis, Oregon
(44°34'N, 123°16'W) from Cupertino, California (37°19'N,
122°62'W)?
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? 6 Two point distance
and heading.
ORIGIN LAT dd.mmss? 37.19 [ENTER] 37°19'
ORIGIN LONG ddd.mmss? 122.82 [ENTER] 122°62'
DEST LAT dd.mmss? 44.34 [ENTER] 44°34"
DEST LONG ddd.mmss? 123.16 [ENTER] 123°16'
HEADING = 353 82 59 [ENTER]
DISTANCE = 438.32 n.mi. [ENTER]
NEXT OPTION (Help)? Repeat with new option
or press A to quit.
PC-1588 (TRS-88 PC-2) SAMPLE PROBLEM 3
Suppose that you want to know what ITD's you would expect to
receive at 35° North, 125° West and at 36°27' North, 126°54' West
from 9940W and 9940Y. To determine these ITD's, proceed as follows
(assume that the GRI's have been loaded as in Sample Problem 1):
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? 5 Predict ITD's.
LAT dd.mmss? 35 [ENTER] ay?
LONG ddd.mmss? 125 [ENTER] 125°
ITD FOR 9949W = 16019.35 [ENTER]
ITD FOR 9948Y = 42584.71 [ENTER]
New Lat/Lon or
Return to menu? N
LAT dd.mmss? 36.27 [ENTER] 36° 27'
LONG ddd.mmss? 126.54 [ENTER] 126°54'
ITD FOR 9946W = 15572.32 [ENTER]
ITD FOR 9946Y = 43006.15 [ENTER]
New Lat/Lon or
Return to menu? R
NEXT OPTION (Help)? Repeat with new option
or press A to quit.
-18-
PC-1588 (TRS~8@ PC-2) SAMPLE PROBLEM 4
Suppose you are receiving an ITD of 16398 from 9948W and
42800 from 9948Y. These ITD's would tell you that your location is
36°47'55"N and 121°47'1l1"W. However, you know that your position
is benchmarked to be at 36°47'36"N and 121°46'58"W, and you wish
to calibrate your PC-1598 so that the ITD's of 16398 and 428008
will give you the latter fix instead of the former. Proceed as
follows (assume the GRI's have been loaded as in Sample Problem
abs
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help) ? 7 Calibrate.
LAT dd.mmss? 36.4736 [ENTER] 36°47'36"
LONG ddd.mmss? 121.4658 [ENTER] 121°45'58"
ITD FOR 9948W? 16388 [ENTER]
ITD FOR 9948Y? 42 8808 [ENTER]
The station baselines have now been modified to
achieve calibration. Now, reenter 16838 and 42808 into
the fixing routine to test the calibration. Calibration
does not modify the permanent station data stored in the
PC-1508. The calibration remains effective until the
GRI's are reloaded by Option 8. NOTE: The affect of
calibration on the accuracy of fixes far removed from
the benchmark has not been studied. The user should use
the calibration option with caution.
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help)? 1 Compute a fix.
ITD FOR 9940W? 16388 [ENTER]
ITD FOR 99480Y? 42899 [ENTER]
LAT = 36 47 35 [ENTER] Lat of fix.
LONG = 121 46 59 [ENTER] Long of fix.
The small discrepancy between this fix and the
benchmark is due to assumptions in the fixing algorithm.
If higher precision is required, the ASF Correction
factor may be used (see Sample Problem 5). Note that you
may need to use the Alternate Solution Option 2 if the
fix obtained above is near 38°52'57"N and 116°5i'l1l'W.
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help) ? Repeat with new option
or press A to quit.
-19-
PC-1568 (TRS-88 PC-2) SAMPLE PROBLEM 5
Suppose you are receiving an ITD of 12153.31 microseconds
from 9960W and 44451.83 microseconds from 996@Y. These ITD's would
tell you that your location is 44°15'@5"N and 67°25'23"W. Entering
the ASF Correction Tables [Ref. 5,6] with these readings, the ASF
Correction for GRI 9960W at 44°15'N and 67°25'W is 1.5 micro-
seconds. Similiarly, the ASF Correction for GRI 996@Y at these
coordinates is 2.7 microseconds. Enter these corrections into your
PC-1508 and recompute your position. (Load the GRI's 9960W and
9968Y using Option 8).
DISPLAY CONTENTS USER RESPONSE COMMENTS
NEXT OPTION (Help) ? 9 ASF Correction.
ASF FOR 9960W? 1.5 [ENTER]
ASF FOR 996@Y? 2.7 [ENTER]
NEXT OPTION (Help)? 1 Compute a fix.
ITD FOR 9960W? 12153.31 [ENTER]
ITD FOR 9940Y? 44451.83 [ENTER]
LAT = 44 15 26 [ENTER]
LONG = 67 26 26 [ENTER]
NEXT OPTION (Help)? Repeat with new option
or press A to quit.
These ASF Corrections have been entered into the
computer. The range of their validity must be checked
with the ASF Correction tables and reentered if they
change. NOTE: If you are using the ASF Correction Tables
and if you wish to calibrate to a benchmark position,
you should first enter the ASF Corrections for your
benchmark and then use the calibration Option 7 (see
Sample Problem 4).
-26-
1A:
20:
28:
26:
>RADIAN
48:
56:
68:
7B:
8a.
38:
188:
128:
138:
PC-1566 (TRS-88 PC-2) PROGRAM LISTING
REM LORAN-C R
OUTINE. rev 86
-23-83. 1730 H
SOURS.
NS=15:REM N9=
# OF MASTER ST
ATIONS
DIM W$¢4)*1,D9
€4)9, P1604), L164
>, G$C2)*6, DC2)
9PC2,2),L¢62, 2)
»BC2), 763), 262
32),AC2)
DIM G¢2)d
:C@=172
98.26: 98=-1:RD
=P] 718@0:C1$='
“:GOTO 128
K=INT (MkX+.
7112 RETURN
P=129.04398/7T-
- 40758+.645764
38E-3kT: RETURN
P=2.7412979/7T-
-A11482+.32774
624E-3%kT
C$=INKEYS 3 IF
C$=""THEN 72
C=ASC (C$): CH=
CHR$ (C-324¢(C>
38)>
FOR C=1TO LEN
(COS): 1F CH=
MIDS ¢(C@$,C; 1)
THEN RETURN
NEXT C: GOTO 78
PAUSE "NEXT OP
TION CHeip>?"
CO$="123456789
AH": GOSUB 72:
PAUSE " "
ON CGOSUB 318
958, 1818, 1848
1898, 398, 1288,
198, 1328, 538, !
4@: GOTO 128
3)
148:
158:
168:
“28a
186:
eS:
198:
200:
218:
228:
248:
258:
268:
270:
-2)-
PRINT '1i - LOR
AN FIX': RINT
"2 - ALTERNATE
SOLN':PRINT *
3 -INPUT DEST
LAT/LONG"
PRINT "4 — HEA
D & DIST TO FI
X' PRINT §5 -
PREDICT ITDs"
PRINT '6 - TWO
POINT DIST &
HEAD': PRINT "2?
CAL IBRATE'
*PRINT (SG NEW
STA. IDs'.-
PRINT '9 - ASF
Corrections".
PRINT '"Q - S7Q
pt
RETURN
IF G1$<>'' THEN
RETURN
FQ@=1:N=1.1NPUT
‘Ist GRI? ‘31%
>PAUSE '
COSUB 386.
COSUB 396.1F ©
B=2THEN 192
F@=1]:N=2: INPUT
"2nd GRI? '3;1$
>PAUSE
COSUB 386
IF A$=]9$THEN
GOSUB 478: IF F
Q=1THEN 258
GOSUB 390: IF F
B=2THEN 218
Fil=1:F2=):1F G
1$=G2$THEN 308
IF PC1, 1)=PC1,
2. AND LO], 1)=L
€1, 2.THEN 318
F2=-1:1F Pdi, 1]
»=P C2, 20AND L¢
1, 1)=L¢2, 2)
THEN 310
PC-1508 (TRS-8@ PC-2)
286:
298:
388:
318:
398:
406:
410:
420:
430:
5
*L=LeN
Fys-}:]F PC2,}
»=P¢2, 29AND LO
2, 1d=L 62, 2)
THEN 318
F2=1:1F PC2, 1)
=P(1, 2)AND L¢2
» 1)=L C1, 22 THEN
318
PRINT "ERROR:
NO TRIPLET.
coTo 138
TOR 1=17TO 2:P:
=PC1,J):L1
L2RL C2. a)
>PAUSE ‘Work ina
“:GOSUP 332:
NEXT ]:GC1)=8:
G62)=@: RETURN
:COSUB 65@:BC])
=$8:2¢1, 1»=2!.
262) 1)=22
45~=21282, 2359345
3)
2Tf 7525327 7THEN
COSUR 58
TKS37THEN
COSUF 6a
2.7 Cj) HTH:
RETURN
C) Es. ag=
LEFT¢ ¢]$,L-1)
>BS=RIGHTS (I$
+ 1):B=ASC (BS)
>BS=CHR$ (B-32
*(B>98)):
RETURN
N8=1: RESTORE
READ 19$, N@, PB
,»L2@
FOR J=1TO N@:
READ W¢(]), DIC
1),P1¢c]>,L1¢1>
SNEXT J
JF J9$< >ASTHEN
458
GOSUB 47@0:1F ©
@=2THEN 4628
440:
458:
460:
470:
928:
eran
=NEXT 1
TE
on
PROGRAM LISTING (cont.)
RETURN
N8=NQ8+1:1— N8<
=NSTHEN 488
PQUSE I#; 1S
NOT CATALOGED"
»F@=2: RETURN
FOR J=1TO N@:
TE W$C])>=BS$
THEN 498
gS 26
RETURN
N=17HEN LET
Cis=]¢:G$¢])-1
¢
PTE NS DTHEN Le”
C2$=1$:G8<%2)=1
$
DOONI=EDGS 1D: KER
OXDEG CPA):
COSUB i278:°.1
sNDEXILOI.NDER
DADEG (L@)
K=RDEDEG (PIC)
3): G0SUB 1273:
OC2,N=KiLO2.N
D=RDXDEG (L191
3:85 TURN
SPAUSr srNG
568:
=e
SIN (P13: P9=
COS (P1>:4=-78
*P9:C1=COKM: C2
=COkC1-M*KM)D 74
D=€1-C2)*¢1-C2
—C1¥MD2P=C2KC]
+C1*MN72)/7D:N=P
9*29
: YY=NiXX=PB:
COSUB 1260:51=
AN: DB=S8/D: U=2
*CS1-DB):W=1-2
*PKCOS (U):V=
COS <U+D@)
PC-1568 (TRS-8@ PC-2) PROGRAM LISTING (cont.)
586:
530:
680:
61@:
€2€:
678:
68:
698:
AS REM
PL 3=L2-L1:93=¢P
>Pb=S
K=C2KC2KSIN (CD
@)*COS (DBKC2%
UKU-] 2 Y=2¥PA
UkKWKSIN (DB)
$2=D8+X-Y:S8=
SIN (S2):S9=
COS (S2):k=SQR
CMxM+ CNKSG-PBX
S842)
P2=ATN CCPBXSI
+NkS8) 7K)
VY=-S8k28: XX=P
SxS9-PBKSBALI:
COSJB 1266:53-
aN
H=C1*kC1-C2)4¥S2
-CYVKO? KSB*COS
€$1+S1-S2).LD=
L1+S3-H
aVYYS—Ma XX=- ONKS
9-P84S8): COSUR
1268: 22=AN:
Ri TURN
REU SOLN
2P-Py)/72: Paz (P!
+P2) 72
=CO*L
SIN (P4):F9=
cos ¢P4)
H=PIPKPD-PBAP A:
L=PO6£P6+HXSIN
(L372)42:D8=2k
ASN ¢SQR ¢(L))
U=2¥*PBXPBXP2*P
P7C1-L 2 U=2*P6
*PB*PS*PS/L: X=
U+U: Y=U-U: T-D@
7SIN (€08):0=4*%
TAT
E=2kCOS (D@):9
=DXKE:C=T-(A-E)
Z2INIEXKCATCKX
>: B=D+D:N2=Y*¢
BrE XY): N3=DEX*K
Y
-23-
706:
73Q:
“aes
Use
738:
800:
818:
+1 Q2=F2KSIN
D2=COkKCO*KENI-N
2+N35764:01=C@
ACT KX-YD 74: 50=
©T-D1+D20xSIN
(DB)
>M=32kT-(20KT-A
I*X-CB+4 KY
2FPHVsV-EXC4- XK):
G=COk¢T72+CO#N
764): Q=-FAGK
TAN ©L3)74
L4=(L4+Q)72.
=SIN (L4):.9=
cos (La
OAL GSM K=ES
COSUP I25¢
ONE Ye-P 2K
=PARR.
1266.
CosJuB
AN
M=Pl +P}
+72: COSUB
:2}=X.%=T1-72
COSJB 1258: °2=
2¥a7¢
Pinel Ss)
~>.
x: RETURN
PREM FIMING RO
UT INE
SiaFTASIN “AY
2: B2=COS
d)-COS ¢BY2)):
C2=SIN (BC2))
E1=201, 19:1F
1=-1 THEN LET
1=2(2,; 1)
E2=201,2):1)F F
2=-1THEN LET E
2=2(2, 2)
C=B1*C2*COS Ce
2)-B2*C1x*COS ¢
E1):S=B1xC2*
SIN (E2)-B2*C1
XSIN CEL)
m7
PC-1588 (TRS-88 PC-2) PROGRAM LISTING (cont.)
838:
968:
918:
926:
936:
+k=B2*kA1-BIxA?.
R=SQR CC*C+S4S
yi V¥¥Y=S: XK=C:
COSUB 125@:G=A
N
2=6+9BXKACS CK
R):YY=B2:XX=C2
*COS €2-E2)+A2
:GCSUB 126@:S2
=AN
i TF © 2=) THEN
LET Pp=PC3
=9QTN CTAN (PRD
7€1-CO8))
43 P=P/RD: X=LE/RC
:%=360: COSUS
P5G:L=xKiTF
v
S@THEN Le
REM OPT i
GOSUB 185:FOR
1=iTO 2
PAUSE ‘ITD FOR
'3G$¢1)3:
INPUT "? "34:
PAUSE :PAUSE "
“;A=At+GC1)-D¢
T)-TC]): 1F ABS
CADCTCIDTHEN 9
40
PRINT "ITD NOT
VALID FOR "3G
$C1):GOTO 928
S4@:4¢] =A721295.¢
P36:NEXT 2
COSUB 772@:
RETURN
956: 1F A@=1THEN
LET A@=-1:G5TO
972
9628: 40=1
976: COSUB 778:
RETURN
980:REM Of7 6
398: INPUT "ORIGIN
1830:
1848:P)=°6:L1=_@:
P2=PS:L2=L95:
GOSUB 658
18050: %=368:X=21/7R
D:GOSUB 1258
>GOSUB 1288
1@6@:PRINT "HEAD!
NG = "3 C0$:M=
168: X=3443.9
17*S@: GOSUB
4@8:PRINT "DI
STANCE = "5%
5 Mami!
1878: RETURN
-24-
PC~1588 (TRS-88 PC-2) PROGRAM LISTING (cont.)
1e8e:
lege.
1]6e:
1220:
118@:
1198:
1208:
2s PAUS
REM ORT 5
GOSUB 185:
COSUB 1378:
FOR K=1TO 2: