62 IERR(N)=0 159 

 C 160 

 C CHECK TO SEE THAT LINE NUMBERS ANO TIMES OF FIXES ARE IN MONOTONIC 161 

 C ASCENDING SEQUENCE. 162 

 C 163 



63 IF (NMBR(N).LE.NMBR(N-l) J NMBR<N)=NMBR(N-1 >+l 161 



64 IF <TIME(N>-TIME(N-1>> 120.120.130 165 



65 120 TIME<N)=TIME(N-1)+SEC 166 



66 130 CONTINUE 167 



67 IF (ISKIP.LE.O) 60 TO 160 168 

 C 169 

 C SKIP LEADING CARD IMAGES THAT CONTAIN BAD DATA. 170 

 C 171 



68 NSTART=ISKIP+1 172 



69 DO 150 N=NSTART.LINE 173 



70 NMBR<N-ISKIP)=NMBR(N> 174 



71 TIME(N-ISKIP)=TIME(N> 175 



72 DO 110 1=1.2 176 



73 D(I«N-ISKIP)=D(I.N> 177 



74 140 RAD(I»N-ISKIP)=RAD(I.N) 178 



75 150 FATH(N-ISKIP)=FATH(N) 179 



76 LINE=LINE-ISKIP 180 



77 160 MSTOP=LINE-l 181 

 C 182 

 C CHECK DISTANCES TO RADAR BEACONS FOR ERRORS. IF DISTANCE/TIME L83 

 C FOR SUCCESSIVE BEACON RANGES INDICATE A SHIP SPEED .GT. 6 KNOTS 184 

 C (3.09 METERS/SEC) .RANGE IS IN ERROR. 185 

 C 186 



78 DO 270 1=1.2 187 



79 DO 200 M=lrMSTOP 188 



80 IF (D(I>M>) 200>200.17C 189 



81 170 NSTArtT=M+l 190 



82 DO 190 N=NSTART.LINE 191 



83 IF (ABS(0(IrN)-D(I.M»)=(TIME(N)-TIME(M))*3. 08865) 200.200.180 192 



84 180 0<I»N)=-1. 193 



85 IERR(N)=IERR(N)+I 194 



86 190 CONTINUE 195 



87 200 CONTINUE 196 

 BB DO 260 M=l.MSTOP 197 

 69 IF (D(I. M>> 210.210.260 198 



90 210 NSTART=M 199 

 C 200 

 C CORRECT ERRONEOUS BEACON RANGES BY LINEAR INTERPOLATION (ON TIME) 201 

 C BETWEEN NON-ERRONEOUS RANGES. 202 

 C 203 



91 DO 230 N=NSTART.LINE 204 



92 IF (D(I(N>> 230.230.220 205 



93 220 NSTOP=N 206 



94 GO TO 240 207 



95 230 CONTINUE 208 

 9o 240 DTIME=TIME(NSTOP)-TIME(NSTART-l) 209 



97 DD1=0(I.NST0P)-0(I.NSTART-1) 210 



98 N=NSTART 211 



99 250 D(I.N)=U(I»NSTART-l)+DDl*(TIME(N)-TIME(NSTART-l))/OTIME 212 



100 N=N+1 213 



101 IF (N-NSTOP) 250.260.260 214 



102 260 CONTINUE 215 



103 270 CONTINUE 216 

 C 217 

 C COMPUTE POSITION OF SHIP FROM DISTANCES FROM THE TWO BEACONS 218 

 C 219 



104 LAG=0 220 



105 DO 300 N=1.LINE 221 

 C 222 

 C MAKE CONSTANT CORRECTION FOR CUBIC AUTOTAPE INTERROGATOR 223 

 C AND CONVERT TO FEET 224 

 C 225 



106 DFT1=(D(1»N)+C0R1)*3. 28083 226 



107 DFT2=(D(2»N)+C0R2)*3. 28083 227 



108 DX1=(SQ0STB+DFT1*0FT1-DFT2*0FT2)/(2.*0ISTB) 228 



109 0Y1=l>FT1*DFT1-DX1«DX1 229 

 C 230 

 C CHECK FOR IMAGINARY ROOT. 231 

 C 232 



110 IF (OY1) 280.280.290 233 



111 280 IERR(N)=IERR(N)+4 234 



112 LAS=LAG+1 235 



113 GO TO 300 236 



114 290 DY1=-SQRT(DY1> 237 



32 



