/* ------------------------------------------------------------------------- Loccalc V1.1, written by Marco, IK2PIH, on 24 Aug 02 and revised on 22 Nov 20. Loccalc calculates longitude and latitude from a 4 or 6 characters world wide locator, calculates distance (kilometers and miles) between two locators and calculates a locator from longitude and latitude. You will be prompted for all inputs and all inputs are validity checked. The calculation of beam heading and distance assumes that Earth is a sphere. Loccalc is a clone of Locator Calculator V2.0, a free software written in Basic by SM0CCM in 1987, and released by the author as a public domain program with no restrictions. This software should compile with any C-compiler and run under any OS. For better results set EAR to earth radius of your location (for my location, north Italy, is 6378 km); my radius should be suitable for all locations at the same latitude of my QTH (45 deg N or S). -------------------------------------------------------------------------- Not Copyrighted 2002, 2020, Marco, IK2PIH, bermarco72@gmail.com This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. ----------------------------------------------------------------------- */ #include #include #include #include #ifndef PI # define PI 3.141592654 #endif #define ISLON 0 #define ISLAT 1 #define EAR 6378.0 /* Earth radius in north Italy (km) */ int chkloc(char *loc); void loc2lonlat(char *loc, double *lon, double *lat); void coord2headist(double lon1, double lat1, double lon2, double lat2, double *cb, double *di, double *dmi); void uppercase(char *st); void lonlat2loc(char *loc, double lon, double lat); int str2deg(char *inputstr, double *res, char t); int main() { char myloc[7]; char otherloc[7]; char inputstr[9]; double mylon,mylat,otherlon,otherlat,cb,di,dmi; char ch; int rv; do {printf("--------------------------------------------------------------------------\n"); printf(" * * * IK2PIH LOCCALC - a clone of SM0CCM LOCATOR CALCULATOR * * *\n"); printf(" MAIN MENU\n"); printf("--------------------------------------------------------------------------\n"); printf("1. BEAM HEADING AND DISTANCE.\n"); printf("2. CONVERT LONG/LAT TO LOCATOR.\n"); printf("3. END\n"); ch=0; while((ch!='1') && (ch!='2') && (ch!='3')) {printf("\nMAKE YOUR CHOICE > "); scanf("%s",inputstr); ch=inputstr[0];} /* BEAM HEADING AND DISTANCE */ if(ch=='1') { printf("--------------------------------------------------------------------------\n"); printf(" * * * IK2PIH LOCCALC - a clone of SM0CCM LOCATOR CALCULATOR * * *\n"); printf(" BEAM HEADING AND DISTANCE\n"); printf("--------------------------------------------------------------------------\n"); do { printf("---------------INSERT YOUR LOCATOR------------------\n"); printf("(TO QUIT: ENTER \"END\" INSTEAD OF YOUR LOCATOR)\n"); printf("YOUR LOCATOR? "); scanf("%s",myloc); uppercase(myloc); rv=chkloc(myloc); if(rv==0) {printf("WRONG LOCATOR !\n\n");} } while(rv==0); if(rv==-1) {loc2lonlat(myloc, &mylon, &mylat); printf("\nYOUR LOCATOR IS = %s\n",myloc); printf("YOUR LONGITUDE IS = %.2lf DEG\n",mylon); printf("YOUR LATITUDE IS = %.2lf DEG\n\n\n",mylat); do { do { printf("\n-------------------INSERT A LOCATOR------------------\n"); printf("(TO QUIT: ENTER \"END\" INSTEAD OF A LOCATOR)\nLOCATOR? "); scanf("%s",otherloc); uppercase(otherloc); /* Read locator and convert in upper case */ rv=chkloc(otherloc); if(rv==0) {printf("WRONG LOCATOR !\n\n");} } while(rv==0); /* Repeat if input is not valid */ if(rv==-1) {loc2lonlat(otherloc, &otherlon, &otherlat); coord2headist(mylon, mylat, otherlon, otherlat, &cb, &di, &dmi); printf("\n************* CALCULATIONS FOR %s *************\n",otherloc); printf("POSITION OF %s\n",otherloc); printf("LONGITUDE = %.2lf DEG\n",otherlon); printf("LATITUDE = %.2lf DEG\n",otherlat); printf("\nBEAM HEADING AND DISTANCE BETWEEN %s",myloc); printf(" AND %s\n",otherloc); printf("BEAM HEADING = %.1lf DEG\n",cb); printf("DISTANCE = %.1lf km\n",di); printf("DISTANCE = %.1lf MLS\n",dmi); printf("***************************************************\n\n"); } } while(rv!=-2); /* Repeat if locator != END */ } } /* CONVERT LONG/LAT TO LOCATOR */ if(ch=='2') { printf("--------------------------------------------------------------------------\n"); printf(" * * * IK2PIH LOCCALC - a clone of SM0CCM LOCATOR CALCULATOR * * *\n"); printf(" CONVERT LONGITUDE/LATITUDE TO LOCATOR\n"); printf("--------------------------------------------------------------------------"); printf("\n\n"); printf("INPUT FORMAT FOR LONGITUDE / LATITUDE = Cnnnsdd\n"); printf("Where - C = W/E/N/S and nnn = degrees.\n"); printf(" sdd = .dd for decimal degrees.\n"); printf(" sdd = 'dd for minutes.\n"); do {printf("\nENTER LONGITUDE - C = W for West, E for East.\n"); printf("> "); scanf("%s",inputstr); uppercase(inputstr); rv=str2deg(inputstr, &mylon, ISLON); if(rv==0) {printf("WRONG LONGITUDE !\n\n");} } while(rv==0); do {printf("\nENTER LATITUDE - C = N for North, S for South.\n"); printf("> "); scanf("%s",inputstr); uppercase(inputstr); rv=str2deg(inputstr, &mylat, ISLAT); if(rv==0) {printf("WRONG LATITUDE !\n\n");} } while(rv==0); lonlat2loc(myloc, mylon, mylat); printf("\nYOUR LOCATOR IS = %s\n",myloc); printf("YOUR LONGITUDE IS = %.2lf DEG\n",mylon); printf("YOUR LATITUDE IS = %.2lf DEG\n\n",mylat); } } while(ch!='3'); return(0); } int chkloc(char *loc) { /* ------------------------------------------------- Check valid locator Input : char *locator = 4 or 6 characters wwlocator. returned value == -1 No error. (Valid locator). returned value == 0 Error. (Invalid locator). Note: also string "END" is considered a valid locator, but returned value is -2. ------------------------------------------------- */ int lenloc,x,i; char t; lenloc=strlen(loc); if (lenloc==4) {strcat(loc,"LM"); lenloc=6;} /* Adjust to middle of square */ x=-1; /* Assumes locator is right */ if (strcmp(loc,"END")==0) x=-2; /* Return -2 if locator=END */ else if (lenloc!=6) x=0; /* force to 0 if locator is wrong */ else for(i=0; i<=5; i++) {t=loc[i]; if(((t>'R')||(t<'A'))&&((i==0)||(i==1))) x=0; /*first 2 char from A to R*/ if(((t>'9')||(t<'0'))&&((i==2)||(i==3))) x=0; /*check the numbers*/ if(((t>'X')||(t<'A'))&&((i==4)||(i==5))) x=0; /*last 2 char from A to X*/ } return(x); } void loc2lonlat(char *loc, double *lon, double *lat) { /* ------------------------------------------------- calculate longitude and latitude Input : locator = 6 characters wwlocator. Output: lon = longitude in decimal degrees; lat = latitude in decimal degrees; ------------------------------------------------- */ *lon=-180.0+((double)loc[0]-65.0)*20.0+((double)loc[2]-48.0)*2.0+((double)loc[4]-64.5)/12.0; *lon=-(*lon); *lat=-90.0+((double)loc[1]-65.0)*10.0+((double)loc[3]-48.0)+((double)loc[5]-64.5)/24.0; return; } void coord2headist(double lon1, double lat1, double lon2, double lat2, double *cb, double *di, double *dmi) { /* ------------------------------------ Calculate beam heading and distance Input : lon1 = Longitude 1 in deg. : lat1 = Latitude 1 in deg. : lon2 = Longitude 1 in deg. : lat2 = Latitude 2 in deg. Output: cb = Beam heading in degr. di = Distance in kilometers. dmi = Distance in miles. ------------------------------------ */ double lo1,la1,lo2,la2,x; lo1=lon1*PI/180.0; la1=lat1*PI/180.0; lo2=lon2*PI/180.0; la2=lat2*PI/180.0; (*di)=acos(cos(la1)*cos(lo1)*cos(la2)*cos(lo2)+cos(la1)*sin(lo1)*cos(la2)*sin(lo2)+sin(la1)*sin(la2))*EAR; (*dmi)=(*di)/1.609; x=atan2(sin(lo1-lo2)*cos(la2),cos(la1)*sin(la2)-sin(la1)*cos(la2)*cos(lo1-lo2))/PI*180.0; if(x<0) (*cb)=x+360.0; else (*cb)=x; return; } void uppercase(char *st) { int le,i; /* ------------------------------------------------- CONVERT STRING TO UPPER CASE Input : st = Variable length. Upper and/or lower case. Output: st = Variable length. Upper case only. ------------------------------------------------- */ le=strlen(st); if(le!=0) { for(i=0;i='a')&&(st[i]<='z')) st[i]=st[i]-32; } } return; } void lonlat2loc(char *loc, double lon, double lat) { double lo,la; int alo,bla,clo,dla,elo,fla; /* ------------------------------------------------- Calculate locator from longitude and latitude Input : lon = Longitude in decimal degrees (+ = West; - = East). lat = Latitude in decimal degrees (+ = North; - = South). Output: locator = 6 characters world wide locator. ------------------------------------------------- */ lo=(-lon+180.0)/20.0; la=(lat+90.0)/10.0; alo=(int)floor(lo); bla=(int)floor(la); lo=(lo-(double)alo)*10.0; la=(la-(double)bla)*10.0; clo=(int)floor(lo); dla=(int)floor(la); elo=(int)floor((lo-(double)clo)*24.0); fla=(int)floor((la-(double)dla)*24.0); loc[0]=(char)(alo+'A'); loc[1]=(char)(bla+'A'); loc[2]=(char)(clo+'0'); loc[3]=(char)(dla+'0'); loc[4]=(char)(elo+'A'); loc[5]=(char)(fla+'A'); loc[6]='\0'; return; } int str2deg(char *inputstr, double *res, char t) { /* ------------------------------------------------ Get decimal degrees from input string Return 0 if error occurs; Return -1 if OK; ------------------------------------------------- */ char degs[4]; char fractdeg[3]; char c,d; double dg,dy; double decdg; double mins; int i; c=inputstr[0]; if((t==ISLON && c!='W' && c!='E') || (t==ISLAT && c!='N' && c!='S')) return(0); /* Extract degrees from string and convert to double*/ for(i=1;i<=3;i++) {if(inputstr[i]>='0' && inputstr[i]<='9') degs[i-1]=inputstr[i]; else return(0);} degs[3]='\0'; sscanf(degs,"%lf",&dg); /* Extract fract of deg from string and converts minutes to decimal deg*/ for(i=5;i<=6;i++) {if(inputstr[i]>='0' && inputstr[i]<='9') fractdeg[i-5]=inputstr[i]; else return(0);} fractdeg[2]='\0'; d=inputstr[4]; if(d=='.') sscanf(fractdeg,"%lf",&decdg); else if((d=='\'') && (fractdeg[0]<='5')) {sscanf(fractdeg,"%lf",&mins); decdg=mins/60.0*100.0;} else return(0); /* Build number in decimal degrees and checks result */ dg=dg+(decdg/100.0); if((t==ISLON && dg>180.0) || (t==ISLAT && dg>90.0)) return(0); /* Minus if longitude east or latitude south */ if(c=='E' || c=='S') {dy=0-dg; dg=dy;} /* Export result */ *res=dg; return(-1); }