// // This file is part of Dire Wolf, an amateur radio packet TNC. // // Copyright (C) 2013, 2014, 2015 John Langner, WB2OSZ // // 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. // // You should have received a copy of the GNU General Public License // along with this program. If not, see . // /*------------------------------------------------------------------ * * Module: latlong.c * * Purpose: Various functions for dealing with latitude and longitude. * * Description: Originally, these were scattered around in many places. * Over time they might all be gathered into one place * for consistency, reuse, and easier maintenance. * *---------------------------------------------------------------*/ #include "direwolf.h" #include #include #include #include #include #include #include #include #include "latlong.h" //#include "textcolor.h" /*------------------------------------------------------------------ * * Name: latitude_to_str * * Purpose: Convert numeric latitude to string for transmission. * * Inputs: dlat - Floating point degrees. * ambiguity - If 1, 2, 3, or 4, blank out that many trailing digits. * * Outputs: slat - String in format ddmm.mm[NS] * Should always be exactly 8 characters + NUL. * * Returns: None * * Idea for future: * Non zero ambiguity removes least significant digits without rounding. * Maybe we could use -1 and -2 to add extra digits using !DAO! as * documented in http://www.aprs.org/datum.txt * * For example, -1 adds one more human readable digit. * lat minutes 12.345 would produce "12.34" and !W5 ! * * -2 would encode almost 2 digits in base 91. * lat minutes 10.0027 would produce "10.00" and !w: ! * *----------------------------------------------------------------*/ void latitude_to_str (double dlat, int ambiguity, char *slat) { char hemi; /* Hemisphere: N or S */ int ideg; /* whole number of degrees. */ double dmin; /* Minutes after removing degrees. */ char smin[8]; /* Minutes in format mm.mm */ if (dlat < -90.) { //text_color_set(DW_COLOR_ERROR); printf ("Latitude is less than -90. Changing to -90.n"); dlat = -90.; } if (dlat > 90.) { //text_color_set(DW_COLOR_ERROR); printf ("Latitude is greater than 90. Changing to 90.n"); dlat = 90.; } if (dlat < 0) { dlat = (- dlat); hemi = 'S'; } else { hemi = 'N'; } ideg = (int)dlat; dmin = (dlat - ideg) * 60.; snprintf (smin, sizeof(smin), "%05.2f", dmin); /* Due to roundoff, 59.9999 could come out as "60.00" */ if (smin[0] == '6') { smin[0] = '0'; ideg++; } sprintf (slat, "%02d%s%c", ideg, smin, hemi); if (ambiguity >= 1) { slat[6] = ' '; if (ambiguity >= 2) { slat[5] = ' '; if (ambiguity >= 3) { slat[3] = ' '; if (ambiguity >= 4) { slat[2] = ' '; } } } } } /* end latitude_to_str */ /*------------------------------------------------------------------ * * Name: longitude_to_str * * Purpose: Convert numeric longitude to string for transmission. * * Inputs: dlong - Floating point degrees. * ambiguity - If 1, 2, 3, or 4, blank out that many trailing digits. * * Outputs: slat - String in format dddmm.mm[NS] * Should always be exactly 9 characters + NUL. * * Returns: None * *----------------------------------------------------------------*/ void longitude_to_str (double dlong, int ambiguity, char *slong) { char hemi; /* Hemisphere: N or S */ int ideg; /* whole number of degrees. */ double dmin; /* Minutes after removing degrees. */ char smin[8]; /* Minutes in format mm.mm */ if (dlong < -180.) { //text_color_set(DW_COLOR_ERROR); printf ("Longitude is less than -180. Changing to -180.n"); dlong = -180.; } if (dlong > 180.) { //text_color_set(DW_COLOR_ERROR); printf ("Longitude is greater than 180. Changing to 180.n"); dlong = 180.; } if (dlong < 0) { dlong = (- dlong); hemi = 'W'; } else { hemi = 'E'; } ideg = (int)dlong; dmin = (dlong - ideg) * 60.; snprintf (smin, sizeof(smin), "%05.2f", dmin); /* Due to roundoff, 59.9999 could come out as "60.00" */ if (smin[0] == '6') { smin[0] = '0'; ideg++; } sprintf (slong, "%03d%s%c", ideg, smin, hemi); /* * The spec says position ambiguity in latitude also * applies to longitude automatically. * Blanking longitude digits is not necessary but I do it * because it makes things clearer. */ if (ambiguity >= 1) { slong[7] = ' '; if (ambiguity >= 2) { slong[6] = ' '; if (ambiguity >= 3) { slong[4] = ' '; if (ambiguity >= 4) { slong[3] = ' '; } } } } } /* end longitude_to_str */ /*------------------------------------------------------------------ * * Name: latitude_to_comp_str * * Purpose: Convert numeric latitude to compressed string for transmission. * * Inputs: dlat - Floating point degrees. * * Outputs: slat - String in format yyyy. * Exactly 4 bytes, no nul terminator. * *----------------------------------------------------------------*/ void latitude_to_comp_str (double dlat, char *clat) { int y, y0, y1, y2, y3; if (dlat < -90.) { //text_color_set(DW_COLOR_ERROR); printf ("Latitude is less than -90. Changing to -90.n"); dlat = -90.; } if (dlat > 90.) { //text_color_set(DW_COLOR_ERROR); printf ("Latitude is greater than 90. Changing to 90.n"); dlat = 90.; } y = (int)round(380926. * (90. - dlat)); y0 = y / (91*91*91); y -= y0 * (91*91*91); y1 = y / (91*91); y -= y1 * (91*91); y2 = y / (91); y -= y2 * (91); y3 = y; clat[0] = y0 + 33; clat[1] = y1 + 33; clat[2] = y2 + 33; clat[3] = y3 + 33; } /*------------------------------------------------------------------ * * Name: longitude_to_comp_str * * Purpose: Convert numeric longitude to compressed string for transmission. * * Inputs: dlong - Floating point degrees. * * Outputs: slat - String in format xxxx. * Exactly 4 bytes, no nul terminator. * *----------------------------------------------------------------*/ void longitude_to_comp_str (double dlong, char *clon) { int x, x0, x1, x2, x3; if (dlong < -180.) { //text_color_set(DW_COLOR_ERROR); printf ("Longitude is less than -180. Changing to -180.n"); dlong = -180.; } if (dlong > 180.) { //text_color_set(DW_COLOR_ERROR); printf ("Longitude is greater than 180. Changing to 180.n"); dlong = 180.; } x = (int)round(190463. * (180. + dlong)); x0 = x / (91*91*91); x -= x0 * (91*91*91); x1 = x / (91*91); x -= x1 * (91*91); x2 = x / (91); x -= x2 * (91); x3 = x; clon[0] = x0 + 33; clon[1] = x1 + 33; clon[2] = x2 + 33; clon[3] = x3 + 33; } /*------------------------------------------------------------------ * * Name: latitude_to_nmea * * Purpose: Convert numeric latitude to strings for NMEA sentence. * * Inputs: dlat - Floating point degrees. * * Outputs: slat - String in format ddmm.mmmm * hemi - Hemisphere or empty string. * * Returns: None * *----------------------------------------------------------------*/ void latitude_to_nmea (double dlat, char *slat, char *hemi) { int ideg; /* whole number of degrees. */ double dmin; /* Minutes after removing degrees. */ char smin[10]; /* Minutes in format mm.mmmm */ if (dlat == G_UNKNOWN) { strcpy (slat, ""); strcpy (hemi, ""); return; } if (dlat < -90.) { //text_color_set(DW_COLOR_ERROR); printf ("Latitude is less than -90. Changing to -90.n"); dlat = -90.; } if (dlat > 90.) { //text_color_set(DW_COLOR_ERROR); printf ("Latitude is greater than 90. Changing to 90.n"); dlat = 90.; } if (dlat < 0) { dlat = (- dlat); strcpy (hemi, "S"); } else { strcpy (hemi, "N"); } ideg = (int)dlat; dmin = (dlat - ideg) * 60.; snprintf (smin, sizeof(smin), "%07.4f", dmin); /* Due to roundoff, 59.99999 could come out as "60.0000" */ if (smin[0] == '6') { smin[0] = '0'; ideg++; } sprintf (slat, "%02d%s", ideg, smin); } /* end latitude_to_str */ /*------------------------------------------------------------------ * * Name: longitude_to_nmea * * Purpose: Convert numeric longitude to strings for NMEA sentence. * * Inputs: dlong - Floating point degrees. * * Outputs: slong - String in format dddmm.mmmm * hemi - Hemisphere or empty string. * * Returns: None * *----------------------------------------------------------------*/ void longitude_to_nmea (double dlong, char *slong, char *hemi) { int ideg; /* whole number of degrees. */ double dmin; /* Minutes after removing degrees. */ char smin[10]; /* Minutes in format mm.mmmm */ if (dlong == G_UNKNOWN) { strcpy (slong, ""); strcpy (hemi, ""); return; } if (dlong < -180.) { //text_color_set(DW_COLOR_ERROR); printf ("longitude is less than -180. Changing to -180.n"); dlong = -180.; } if (dlong > 180.) { //text_color_set(DW_COLOR_ERROR); printf ("longitude is greater than 180. Changing to 180.n"); dlong = 180.; } if (dlong < 0) { dlong = (- dlong); strcpy (hemi, "W"); } else { strcpy (hemi, "E"); } ideg = (int)dlong; dmin = (dlong - ideg) * 60.; snprintf (smin, sizeof(smin), "%07.4f", dmin); /* Due to roundoff, 59.99999 could come out as "60.0000" */ if (smin[0] == '6') { smin[0] = '0'; ideg++; } sprintf (slong, "%03d%s", ideg, smin); } /* end longitude_to_nmea */ /*------------------------------------------------------------------ * * Function: latitude_from_nmea * * Purpose: Convert NMEA latitude encoding to degrees. * * Inputs: pstr - Pointer to numeric string. * phemi - Pointer to following field. Should be N or S. * * Returns: Double precision value in degrees. Negative for South. * * Description: Latitude field has * 2 digits for degrees * 2 digits for minutes * period * Variable number of fractional digits for minutes. * I've seen 2, 3, and 4 fractional digits. * * * Bugs: Very little validation of data. * * Errors: Return constant G_UNKNOWN for any type of error. * *------------------------------------------------------------------*/ double latitude_from_nmea (char *pstr, char *phemi) { double lat; if ( ! isdigit((uint)(pstr[0]))) return (G_UNKNOWN); if (pstr[4] != '.') return (G_UNKNOWN); lat = (pstr[0] - '0') * 10 + (pstr[1] - '0') + atof(pstr+2) / 60.0; if (lat < 0 || lat > 90) { //text_color_set(DW_COLOR_ERROR); printf("Error: Latitude not in range of 0 to 90.\n"); } // Saw this one time: // $GPRMC,000000,V,0000.0000,0,00000.0000,0,000,000,000000,,*01 // If location is unknown, I think the hemisphere should be // an empty string. TODO: Check on this. // 'V' means void, so sentence should be discarded rather than // trying to extract any data from it. if (*phemi != 'N' && *phemi != 'S' && *phemi != '\0') { //text_color_set(DW_COLOR_ERROR); printf("Error: Latitude hemisphere should be N or S.\n"); } if (*phemi == 'S') lat = ( - lat); return (lat); } /*------------------------------------------------------------------ * * Function: longitude_from_nmea * * Purpose: Convert NMEA longitude encoding to degrees. * * Inputs: pstr - Pointer to numeric string. * phemi - Pointer to following field. Should be E or W. * * Returns: Double precision value in degrees. Negative for West. * * Description: Longitude field has * 3 digits for degrees * 2 digits for minutes * period * Variable number of fractional digits for minutes * * * Bugs: Very little validation of data. * * Errors: Return constant G_UNKNOWN for any type of error. * *------------------------------------------------------------------*/ double longitude_from_nmea (char *pstr, char *phemi) { double lon; if ( ! isdigit((uint)(pstr[0]))) return (G_UNKNOWN); if (pstr[5] != '.') return (G_UNKNOWN); lon = (pstr[0] - '0') * 100 + (pstr[1] - '0') * 10 + (pstr[2] - '0') + atof(pstr+3) / 60.0; if (lon < 0 || lon > 180) { //text_color_set(DW_COLOR_ERROR); printf("Error: Longitude not in range of 0 to 180.\n"); } if (*phemi != 'E' && *phemi != 'W' && *phemi != '\0') { //text_color_set(DW_COLOR_ERROR); printf("Error: Longitude hemisphere should be E or W.\n"); } if (*phemi == 'W') lon = ( - lon); return (lon); } /*------------------------------------------------------------------ * * Function: ll_distance_km * * Purpose: Calculate distance between two locations. * * Inputs: lat1, lon1 - One location, in degrees. * lat2, lon2 - other location * * Returns: Distance in km. * * Description: The Ubiquitous Haversine formula. * *------------------------------------------------------------------*/ #define R 6371 double ll_distance_km (double lat1, double lon1, double lat2, double lon2) { double a; lat1 *= M_PI / 180; lon1 *= M_PI / 180; lat2 *= M_PI / 180; lon2 *= M_PI / 180; a = pow(sin((lat2-lat1)/2),2) + cos(lat1) * cos(lat2) * pow(sin((lon2-lon1)/2),2); return (R * 2 *atan2(sqrt(a), sqrt(1-a))); } /*------------------------------------------------------------------ * * Function: ll_bearing_deg * * Purpose: Calculate bearing between two locations. * * Inputs: lat1, lon1 - starting location, in degrees. * lat2, lon2 - destination location * * Returns: Initial Bearing, in degrees. * The calculation produces Range +- 180 degrees. * But I think that 0 - 360 would be more customary? * *------------------------------------------------------------------*/ double ll_bearing_deg (double lat1, double lon1, double lat2, double lon2) { double b; lat1 *= M_PI / 180; lon1 *= M_PI / 180; lat2 *= M_PI / 180; lon2 *= M_PI / 180; b = atan2 (sin(lon2-lon1) * cos(lat2), cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(lon2-lon1)); b *= 180 / M_PI; if (b < 0) b += 360; return (b); } /*------------------------------------------------------------------ * * Function: ll_dest_lat * ll_dest_lon * * Purpose: Calculate the destination location given a starting point, * distance, and bearing, * * Inputs: lat1, lon1 - starting location, in degrees. * dist - distance in km. * bearing - direction in degrees. Shouldn't matter * if it is in +- 180 or 0 to 360 range. * * Returns: New latitude or longitude. * *------------------------------------------------------------------*/ double ll_dest_lat (double lat1, double lon1, double dist, double bearing) { double lat2; lat1 *= M_PI / 180; // Everything to radians. lon1 *= M_PI / 180; bearing *= M_PI / 180; lat2 = asin(sin(lat1) * cos(dist/R) + cos(lat1) * sin(dist/R) * cos(bearing)); lat2 *= 180 / M_PI; // Back to degrees. return (lat2); } double ll_dest_lon (double lat1, double lon1, double dist, double bearing) { double lon2; double lat2; lat1 *= M_PI / 180; // Everything to radians. lon1 *= M_PI / 180; bearing *= M_PI / 180; lat2 = asin(sin(lat1) * cos(dist/R) + cos(lat1) * sin(dist/R) * cos(bearing)); lon2 = lon1 + atan2(sin(bearing) * sin(dist/R) * cos(lat1), cos(dist/R) - sin(lat1) * sin(lat2)); lon2 *= 180 / M_PI; // Back to degrees. return (lon2); } /*------------------------------------------------------------------ * * Function: ll_from_grid_square * * Purpose: Convert Maidenhead locator to latitude and longitude. * * Inputs: maidenhead - 2, 4, 6, 8, 10, or 12 character grid square locator. * * Outputs: dlat, dlon - Latitude and longitude. * Original values unchanged if error. * * Returns: 1 for success, 0 if error. * * Reference: A good converter for spot checking. Only handles 4 or 6 characters :-( * http://home.arcor.de/waldemar.kebsch/The_Makrothen_Contest/fmaidenhead.html * * Rambling: What sort of resolution does this provide? * For 8 character form, each latitude unit is 0.25 minute. * (Longitude can be up to twice that around the equator.) * 6371 km * 2 * pi * 0.25 / 60 / 360 = 0.463 km. Is that right? * * Using this calculator, http://www.earthpoint.us/Convert.aspx * It gives lower left corner of square rather than the middle. :-( * * FN42MA00 --> 19T 334361mE 4651711mN * FN42MA11 --> 19T 335062mE 4652157mN * ------ ------- * 701 446 meters difference. * * With another two pairs, we are down around 2 meters for latitude. * *------------------------------------------------------------------*/ #define MH_MIN_PAIR 1 #define MH_MAX_PAIR 6 #define MH_UNITS ( 18 * 10 * 24 * 10 * 24 * 10 * 2 ) static const struct { char *position; char min_ch; char max_ch; int value; } mh_pair[MH_MAX_PAIR] = { { "first", 'A', 'R', 10 * 24 * 10 * 24 * 10 * 2 }, { "second", '0', '9', 24 * 10 * 24 * 10 * 2 }, { "third", 'A', 'X', 10 * 24 * 10 * 2 }, { "fourth", '0', '9', 24 * 10 * 2 }, { "fifth", 'A', 'X', 10 * 2 }, { "sixth", '0', '9', 2 } }; // Even so we can get center of square. #if 1 int ll_from_grid_square (char *maidenhead, double *dlat, double *dlon) { char mh[16]; /* Local copy, changed to upper case. */ int ilat = 0, ilon = 0; /* In units in table above. */ char *p; int n; int np = strlen(maidenhead) / 2; /* Number of pairs of characters. */ if (strlen(maidenhead) %2 != 0 || np < MH_MIN_PAIR || np > MH_MAX_PAIR) { //text_color_set(DW_COLOR_ERROR); printf("Maidenhead locator \"%s\" must from 1 to %d pairs of characters.\n", maidenhead, MH_MAX_PAIR); return (0); } strlcpy (mh, maidenhead, sizeof(mh)); for (p = mh; *p != '\0'; p++) { if (islower((uint)*p)) *p = toupper((uint)*p); } for (n = 0; n < np; n++) { if (mh[2*n] < mh_pair[n].min_ch || mh[2*n] > mh_pair[n].max_ch || mh[2*n+1] < mh_pair[n].min_ch || mh[2*n+1] > mh_pair[n].max_ch) { //text_color_set(DW_COLOR_ERROR); printf("The %s pair of characters in Maidenhead locator \"%s\" must be in range of %c thru %c.\n", mh_pair[n].position, maidenhead, mh_pair[n].min_ch, mh_pair[n].max_ch); return (0); } ilon += ( mh[2*n] - mh_pair[n].min_ch ) * mh_pair[n].value; ilat += ( mh[2*n+1] - mh_pair[n].min_ch ) * mh_pair[n].value; if (n == np-1) { // If last pair, take center of square. ilon += mh_pair[n].value / 2; ilat += mh_pair[n].value / 2; } } *dlat = (double)ilat / MH_UNITS * 180. - 90.; *dlon = (double)ilon / MH_UNITS * 360. - 180.; ////text_color_set(DW_COLOR_DEBUG); //printf("DEBUG: Maidenhead conversion \"%s\" -> %.6f %.6f\n", maidenhead, *dlat, *dlon); return (1); } #else int ll_from_grid_square (char *maidenhead, double *dlat, double *dlon) { double lat, lon; char mh[16]; if (strlen(maidenhead) != 2 && strlen(maidenhead) != 4 && strlen(maidenhead) != 6 && strlen(maidenhead) != 8) { //text_color_set(DW_COLOR_ERROR); printf("Maidenhead locator \"%s\" must 2, 4, 6, or 8 characters.\n", maidenhead); return (0); } strcpy (mh, maidenhead); if (islower((uint)mh[0])) mh[0] = toupper((uint)mh[0]); if (islower((uint)mh[1])) mh[1] = toupper((uint)mh[1]); if (mh[0] < 'A' || mh[0] > 'R' || mh[1] < 'A' || mh[1] > 'R') { //text_color_set(DW_COLOR_ERROR); printf("The first pair of characters in Maidenhead locator \"%s\" must be in range of A thru R.\n", maidenhead); return (0); } /* Lon: 360 deg / 18 squares = 20 deg / square */ /* Lat: 180 deg / 18 squares = 10 deg / square */ lon = (mh[0] - 'A') * 20 - 180; lat = (mh[1] - 'A') * 10 - 90; if (strlen(mh) >= 4) { if ( ! isdigit((uint)mh[2]) || ! isdigit((uint)mh[3]) ) { //text_color_set(DW_COLOR_ERROR); printf("The second pair of characters in Maidenhead locator \"%s\" must be digits.\n", maidenhead); return (0); } /* Lon: 20 deg / 10 squares = 2 deg / square */ /* Lat: 10 deg / 10 squares = 1 deg / square */ lon += (mh[2] - '0') * 2; lat += (mh[3] - '0'); if (strlen(mh) >=6) { if (islower((uint)mh[4])) mh[4] = toupper((uint)mh[4]); if (islower((uint)mh[5])) mh[5] = toupper((uint)mh[5]); if (mh[4] < 'A' || mh[4] > 'X' || mh[5] < 'A' || mh[5] > 'X') { //text_color_set(DW_COLOR_ERROR); printf("The third pair of characters in Maidenhead locator \"%s\" must be in range of A thru X.\n", maidenhead); return (0); } /* Lon: 2 deg / 24 squares = 5 minutes / square */ /* Lat: 1 deg / 24 squares = 2.5 minutes / square */ lon += (mh[4] - 'A') * 5.0 / 60.0; lat += (mh[5] - 'A') * 2.5 / 60.0; if (strlen(mh) >= 8) { if ( ! isdigit((uint)mh[6]) || ! isdigit((uint)mh[7]) ) { //text_color_set(DW_COLOR_ERROR); printf("The fourth pair of characters in Maidenhead locator \"%s\" must be digits.\n", maidenhead); return (0); } /* Lon: 5 min / 10 squares = 0.5 minutes / square */ /* Lat: 2.5 min / 10 squares = 0.25 minutes / square */ lon += (mh[6] - '0') * 0.50 / 60.0; lat += (mh[7] - '0') * 0.25 / 60.0; lon += 0.250 / 60.0; /* Move from corner to center of square */ lat += 0.125 / 60.0; } else { lon += 2.5 / 60.0; /* Move from corner to center of square */ lat += 1.25 / 60.0; } } else { lon += 1.0; /* Move from corner to center of square */ lat += 0.5; } } else { lon += 10; /* Move from corner to center of square */ lat += 5; } ////text_color_set(DW_COLOR_DEBUG); //printf("DEBUG: Maidenhead conversion \"%s\" -> %.6f %.6f\n", maidenhead, lat, lon); *dlat = lat; *dlon = lon; return (1); } #endif /* end ll_from_grid_square */ #if LLTEST /* gcc -o lltest -DLLTEST latlong.c textcolor.o misc.a && lltest */ int main (int argc, char *argv[]) { char result[20]; int errors = 0; int ok; double dlat, dlon; double d, b; /* Latitude to APRS format. */ latitude_to_str (45.25, 0, result); if (strcmp(result, "4515.00N") != 0) { errors++; printf ("Error 1.1: Did not expect \"%s\"\n", result); } latitude_to_str (-45.25, 0, result); if (strcmp(result, "4515.00S") != 0) { errors++; printf ("Error 1.2: Did not expect \"%s\"\n", result); } latitude_to_str (45.999830, 0, result); if (strcmp(result, "4559.99N") != 0) { errors++; printf ("Error 1.3: Did not expect \"%s\"\n", result); } latitude_to_str (45.99999, 0, result); if (strcmp(result, "4600.00N") != 0) { errors++; printf ("Error 1.4: Did not expect \"%s\"\n", result); } latitude_to_str (45.999830, 1, result); if (strcmp(result, "4559.9 N") != 0) { errors++; printf ("Error 1.5: Did not expect \"%s\"\n", result); } latitude_to_str (45.999830, 2, result); if (strcmp(result, "4559. N") != 0) { errors++; printf ("Error 1.6: Did not expect \"%s\"\n", result); } latitude_to_str (45.999830, 3, result); if (strcmp(result, "455 . N") != 0) { errors++; printf ("Error 1.7: Did not expect \"%s\"\n", result); } latitude_to_str (45.999830, 4, result); if (strcmp(result, "45 . N") != 0) { errors++; printf ("Error 1.8: Did not expect \"%s\"\n", result); } /* Longitude to APRS format. */ longitude_to_str (45.25, 0, result); if (strcmp(result, "04515.00E") != 0) { errors++; printf ("Error 2.1: Did not expect \"%s\"\n", result); } longitude_to_str (-45.25, 0, result); if (strcmp(result, "04515.00W") != 0) { errors++; printf ("Error 2.2: Did not expect \"%s\"\n", result); } longitude_to_str (45.999830, 0, result); if (strcmp(result, "04559.99E") != 0) { errors++; printf ("Error 2.3: Did not expect \"%s\"\n", result); } longitude_to_str (45.99999, 0, result); if (strcmp(result, "04600.00E") != 0) { errors++; printf ("Error 2.4: Did not expect \"%s\"\n", result); } longitude_to_str (45.999830, 1, result); if (strcmp(result, "04559.9 E") != 0) { errors++; printf ("Error 2.5: Did not expect \"%s\"\n", result); } longitude_to_str (45.999830, 2, result); if (strcmp(result, "04559. E") != 0) { errors++; printf ("Error 2.6: Did not expect \"%s\"\n", result); } longitude_to_str (45.999830, 3, result); if (strcmp(result, "0455 . E") != 0) { errors++; printf ("Error 2.7: Did not expect \"%s\"\n", result); } longitude_to_str (45.999830, 4, result); if (strcmp(result, "045 . E") != 0) { errors++; printf ("Error 2.8: Did not expect \"%s\"\n", result); } /* Compressed format. */ /* Protocol spec example has <*e7 but I got <*e8 due to rounding rather than truncation to integer. */ memset(result, 0, sizeof(result)); latitude_to_comp_str (-90.0, result); if (strcmp(result, "{{!!") != 0) { errors++; printf ("Error 3.1: Did not expect \"%s\"\n", result); } latitude_to_comp_str (49.5, result); if (strcmp(result, "5L!!") != 0) { errors++; printf ("Error 3.2: Did not expect \"%s\"\n", result); } latitude_to_comp_str (90.0, result); if (strcmp(result, "!!!!") != 0) { errors++; printf ("Error 3.3: Did not expect \"%s\"\n", result); } longitude_to_comp_str (-180.0, result); if (strcmp(result, "!!!!") != 0) { errors++; printf ("Error 3.4: Did not expect \"%s\"\n", result); } longitude_to_comp_str (-72.75, result); if (strcmp(result, "<*e8") != 0) { errors++; printf ("Error 3.5: Did not expect \"%s\"\n", result); } longitude_to_comp_str (180.0, result); if (strcmp(result, "{{!!") != 0) { errors++; printf ("Error 3.6: Did not expect \"%s\"\n", result); } // to be continued for others... NMEA... /* Distance & bearing - Take a couple examples from other places and see if we get similar results. */ // http://www.movable-type.co.uk/scripts/latlong.html d = ll_distance_km (35., 45., 35., 135.); b = ll_bearing_deg (35., 45., 35., 135.); if (d < 7862 || d > 7882) { errors++; printf ("Error 5.1: Did not expect distance %.1f\n", d); } if (b < 59.7 || b > 60.3) { errors++; printf ("Error 5.2: Did not expect bearing %.1f\n", b); } // Sydney to Kinsale. https://woodshole.er.usgs.gov/staffpages/cpolloni/manitou/ccal.htm d = ll_distance_km (-33.8688, 151.2093, 51.7059, -8.5222); b = ll_bearing_deg (-33.8688, 151.2093, 51.7059, -8.5222); if (d < 17435 || d > 17455) { errors++; printf ("Error 5.3: Did not expect distance %.1f\n", d); } if (b < 327-1 || b > 327+1) { errors++; printf ("Error 5.4: Did not expect bearing %.1f\n", b); } /* * More distance and bearing. * Here we will start at some location1 (lat1,lon1) and go some distance (d1) at some bearing (b1). * This results in a new location2 (lat2, lon2). * We then calculate the distance and bearing from location1 to location2 and compare with the intention. */ int lat1, lon1, d1 = 10, b1; double lat2, lon2, d2, b2; for (lat1 = -60; lat1 <= 60; lat1 += 30) { for (lon1 = -180; lon1 <= 180; lon1 +=30) { for (b1 = 0; b1 < 360; b1 += 15) { lat2 = ll_dest_lat ((double)lat1, (double)lon1, (double)d1, (double)b1); lon2 = ll_dest_lon ((double)lat1, (double)lon1, (double)d1, (double)b1); d2 = ll_distance_km ((double)lat1, (double)lon1, lat2, lon2); b2 = ll_bearing_deg ((double)lat1, (double)lon1, lat2, lon2); if (b2 > 359.9 && b2 < 360.1) b2 = 0; // must be within 0.1% of distance and 0.1 degree. if (d2 < 0.999 * d1 || d2 > 1.001 * d1) { errors++; printf ("Error 5.8: lat1=%d, lon2=%d, d1=%d, b1=%d, d2=%.2f\n", lat1, lon1, d1, b1, d2); } if (b2 < b1 - 0.1 || b2 > b1 + 0.1) { errors++; printf ("Error 5.9: lat1=%d, lon2=%d, d1=%d, b1=%d, b2=%.2f\n", lat1, lon1, d1, b1, b2); } } } } /* Maidenhead locator to lat/long. */ ok = ll_from_grid_square ("BL11", &dlat, &dlon); if (!ok || dlat < 20.4999999 || dlat > 21.5000001 || dlon < -157.0000001 || dlon > -156.9999999) { errors++; printf ("Error 7.1: Did not expect %.6f %.6f\n", dlat, dlon); } ok = ll_from_grid_square ("BL11BH", &dlat, &dlon); if (!ok || dlat < 21.31249 || dlat > 21.31251 || dlon < -157.87501 || dlon > -157.87499) { errors++; printf ("Error 7.2: Did not expect %.6f %.6f\n", dlat, dlon); } #if 0 // TODO: add more test cases after comparing results with other cconverters. // Many other converters are limited to smaller number of characters, // or return corner rather than center of square, or return 3 decimal places for degrees. ok = ll_from_grid_square ("BL11BH16", &dlat, &dlon); if (!ok || dlat < 21.? || dlat > 21.? || dlon < -157.? || dlon > -157.?) { errors++; printf ("Error 7.3: Did not expect %.6f %.6f\n", dlat, dlon); } ok = ll_from_grid_square ("BL11BH16oo", &dlat, &dlon); if (!ok || dlat < 21.? || dlat > 21.? || dlon < -157.? || dlon > -157.?) { errors++; printf ("Error 7.4: Did not expect %.6f %.6f\n", dlat, dlon); } ok = ll_from_grid_square ("BL11BH16oo66", &dlat, &dlon); if (!ok || dlat < 21.? || dlat > 21.? || dlon < -157.? || dlon > -157.?) { errors++; printf ("Error 7.5: Did not expect %.6f %.6f\n", dlat, dlon); } #endif if (errors > 0) { //text_color_set (DW_COLOR_ERROR); printf ("\nLocation Coordinate Conversion Test - FAILED!\n"); exit (EXIT_FAILURE); } //text_color_set (DW_COLOR_REC); printf ("\nLocation Coordinate Conversion Test - SUCCESS!\n"); exit (EXIT_SUCCESS); } #endif /* end latlong.c */