UTMUPS.cpp

Go to the documentation of this file.
00001 /**
00002  * \file UTMUPS.cpp
00003  * \brief Implementation for GeographicLib::UTMUPS class
00004  *
00005  * Copyright (c) Charles Karney (2008, 2009, 2010) <charles@karney.com>
00006  * and licensed under the LGPL.  For more information, see
00007  * http://geographiclib.sourceforge.net/
00008  **********************************************************************/
00009 
00010 #include "GeographicLib/UTMUPS.hpp"
00011 #include "GeographicLib/MGRS.hpp"
00012 #include "GeographicLib/PolarStereographic.hpp"
00013 #include "GeographicLib/TransverseMercator.hpp"
00014 #include <iomanip>
00015 
00016 #define GEOGRAPHICLIB_UTMUPS_CPP "$Id: UTMUPS.cpp 6814 2010-02-04 22:33:41Z karney $"
00017 
00018 RCSID_DECL(GEOGRAPHICLIB_UTMUPS_CPP)
00019 RCSID_DECL(GEOGRAPHICLIB_UTMUPS_HPP)
00020 
00021 namespace GeographicLib {
00022 
00023   using namespace std;
00024 
00025   const Math::real UTMUPS::falseeasting[4] =
00026     { MGRS::upseasting * MGRS::tile, MGRS::upseasting * MGRS::tile,
00027       MGRS::utmeasting * MGRS::tile, MGRS::utmeasting* MGRS::tile };
00028   const Math::real UTMUPS::falsenorthing[4] =
00029     { MGRS::upseasting * MGRS::tile, MGRS::upseasting * MGRS::tile,
00030       MGRS::maxutmSrow * MGRS::tile, MGRS::minutmNrow * MGRS::tile };
00031   const Math::real UTMUPS::mineasting[4] =
00032     { MGRS::minupsSind * MGRS::tile,  MGRS::minupsNind * MGRS::tile,
00033       MGRS::minutmcol * MGRS::tile,  MGRS::minutmcol * MGRS::tile };
00034   const Math::real UTMUPS::maxeasting[4] =
00035     { MGRS::maxupsSind * MGRS::tile,  MGRS::maxupsNind * MGRS::tile,
00036       MGRS::maxutmcol * MGRS::tile,  MGRS::maxutmcol * MGRS::tile };
00037   const Math::real UTMUPS::minnorthing[4] =
00038     { MGRS::minupsSind * MGRS::tile,  MGRS::minupsNind * MGRS::tile,
00039       MGRS::minutmSrow * MGRS::tile,
00040       (MGRS::minutmNrow + MGRS::minutmSrow - MGRS::maxutmSrow) * MGRS::tile };
00041   const Math::real UTMUPS::maxnorthing[4] =
00042     { MGRS::maxupsSind * MGRS::tile,  MGRS::maxupsNind * MGRS::tile,
00043       (MGRS::maxutmSrow + MGRS::maxutmNrow - MGRS::minutmNrow) * MGRS::tile,
00044       MGRS::maxutmNrow * MGRS::tile };
00045 
00046   int UTMUPS::StandardZone(real lat, real lon, int setzone) {
00047     if (setzone < MINPSEUDOZONE || setzone > MAXZONE)
00048       throw GeographicErr("Illegal zone requested " + str(setzone));
00049     if (setzone >= MINZONE)
00050       return setzone;
00051     // Assume lon is in [-180, 360].
00052     if (setzone == UTM || (lat >= -80 && lat < 84)) {
00053       // Assume lon is in [-180, 360].
00054       int ilon = int(floor(lon));
00055       if (ilon >= 180)
00056         ilon -= 360;
00057       int zone = (ilon + 186)/6;
00058       int band = MGRS::LatitudeBand(lat);
00059       if (band == 7 && zone == 31 && ilon >= 3)
00060         zone = 32;
00061       else if (band == 9 && ilon >= 0 && ilon < 42)
00062         zone = 2 * ((ilon + 183)/12) + 1;
00063       return zone;
00064     } else
00065       return UPS;
00066   }
00067 
00068   void UTMUPS::Forward(real lat, real lon,
00069                        int& zone, bool& northp, real& x, real& y,
00070                        real& gamma, real& k,
00071                        int setzone, bool mgrslimits) {
00072     CheckLatLon(lat, lon);
00073     bool northp1 = lat >= 0;
00074     int zone1 = StandardZone(lat, lon, setzone);
00075     real x1, y1, gamma1, k1;
00076     bool utmp = zone1 != UPS;
00077     if (utmp) {
00078       real
00079         lon0 = CentralMeridian(zone1),
00080         dlon = lon - lon0;
00081       dlon = abs(dlon - 360 * floor((dlon + 180)/360));
00082       if (dlon > 60)
00083         // Check isn't really necessary because CheckCoords catches this case.
00084         // But this allows a more meaningful error message to be given.
00085         throw GeographicErr("Longitude " + str(lon)
00086                             + "d more than 60d from center of UTM zone "
00087                             + str(zone1));
00088       TransverseMercator::UTM.Forward(lon0, lat, lon, x1, y1, gamma1, k1);
00089     } else {
00090       if (abs(lat) < 70)
00091         // Check isn't really necessary ... (see above).
00092         throw GeographicErr("Latitude " + str(lat) + "d more than 20d from "
00093                             + (northp1 ? "N" : "S") + " pole");
00094       PolarStereographic::UPS.Forward(northp1, lat, lon, x1, y1, gamma1, k1);
00095     }
00096     int ind = (utmp ? 2 : 0) + (northp1 ? 1 : 0);
00097     x1 += falseeasting[ind];
00098     y1 += falsenorthing[ind];
00099     if (! CheckCoords(zone1 != UPS, northp1, x1, y1, mgrslimits, false) )
00100       throw GeographicErr("Latitude " + str(lat) + ", longitude " + str(lon)
00101                           + " out of legal range for "
00102                           + (utmp ? "UTM zone " + str(zone1) : "UPS"));
00103     zone = zone1;
00104     northp = northp1;
00105     x = x1;
00106     y = y1;
00107     gamma = gamma1;
00108     k = k1;
00109   }
00110 
00111   void UTMUPS::Reverse(int zone, bool northp, real x, real y,
00112                        real& lat, real& lon, real& gamma, real& k,
00113                        bool mgrslimits) {
00114     if (! (zone >= MINZONE && zone <= MAXZONE))
00115       throw GeographicErr("Zone " + str(zone) + " not in range [0, 60]");
00116     bool utmp = zone != UPS;
00117     CheckCoords(utmp, northp, x, y, mgrslimits);
00118     int ind = (utmp ? 2 : 0) + (northp ? 1 : 0);
00119     x -= falseeasting[ind];
00120     y -= falsenorthing[ind];
00121     if (utmp)
00122       TransverseMercator::UTM.Reverse(CentralMeridian(zone),
00123                                       x, y, lat, lon, gamma, k);
00124     else
00125       PolarStereographic::UPS.Reverse(northp, x, y, lat, lon, gamma, k);
00126   }
00127 
00128   void UTMUPS::CheckLatLon(real lat, real lon) {
00129     if (! (lat >= -90 && lat <= 90))
00130       throw GeographicErr("Latitude " + str(lat) + "d not in [-90d, 90d]");
00131     if (! (lon >= -180 && lon <= 360))
00132       throw GeographicErr("Latitude " + str(lon) + "d not in [-180d, 360d]");
00133     }
00134 
00135   bool UTMUPS::CheckCoords(bool utmp, bool northp, real x, real y,
00136                            bool mgrslimits, bool throwp) {
00137     // Limits are all multiples of 100km and are all closed on the both ends.
00138     // Failure tests are all negated success tests so that NaNs fail.
00139     real slop = mgrslimits ? 0 : MGRS::tile;
00140     int ind = (utmp ? 2 : 0) + (northp ? 1 : 0);
00141     if (! (x >= mineasting[ind] - slop && x <= maxeasting[ind] + slop) ) {
00142       if (!throwp) return false;
00143       throw GeographicErr("Easting " + str(x/1000) + "km not in "
00144                           + (mgrslimits ? "MGRS/" : "")
00145                           + (utmp ? "UTM" : "UPS") + " range for "
00146                           + (northp ? "N" : "S" ) + " hemisphere ["
00147                           + str((mineasting[ind] - slop)/1000) + "km, "
00148                           + str((maxeasting[ind] + slop)/1000) + "km]");
00149     }
00150     if (! (y >= minnorthing[ind] - slop && y <= maxnorthing[ind] + slop) ) {
00151       if (!throwp) return false;
00152       throw GeographicErr("Northing " + str(y/1000) + "km not in "
00153                           + (mgrslimits ? "MGRS/" : "")
00154                           + (utmp ? "UTM" : "UPS") + " range for "
00155                           + (northp ? "N" : "S" ) + " hemisphere ["
00156                           + str((minnorthing[ind] - slop)/1000) + "km, "
00157                           + str((maxnorthing[ind] + slop)/1000) + "km]");
00158     }
00159     return true;
00160   }
00161 
00162   void UTMUPS::DecodeZone(const std::string& zonestr, int& zone, bool& northp) {
00163     unsigned zlen = unsigned(zonestr.size());
00164     if (zlen == 0)
00165       throw GeographicErr("Empty zone specification");
00166     if (zlen > 3)
00167       throw GeographicErr("More than 3 characters in zone specification "
00168                           + zonestr);
00169     char hemi = toupper(zonestr[zlen - 1]);
00170     bool northp1 = hemi == 'N';
00171     if (! (northp1 || hemi == 'S'))
00172       throw GeographicErr(string("Illegal hemisphere letter ") + hemi + " in "
00173                           + zonestr + ", specify N or S");
00174     if (zlen == 1)
00175       zone = UPS;
00176     else {
00177       const char* c = zonestr.c_str();
00178       char* q;
00179       int zone1 = strtol(c, &q, 10);
00180       if (q == c)
00181         throw GeographicErr("No zone number found in " + zonestr);
00182       if (q - c != int(zlen) - 1)
00183         throw GeographicErr("Extra text " +
00184                             zonestr.substr(q - c, int(zlen) - 1 - (q - c)) +
00185                             " in UTM/UPS zone " + zonestr);
00186       if (zone1 == UPS)
00187         // Don't allow 0N as an alternative to N for UPS coordinates
00188         throw GeographicErr("Illegal zone 0 in " + zonestr +
00189                             ", use just " + hemi + " for UPS");
00190       if (!(zone1 >= MINUTMZONE && zone1 <= MAXUTMZONE))
00191         throw GeographicErr("Zone " + str(zone1) + " not in range [1, 60]");
00192       zone = zone1;
00193     }
00194     northp = northp1;
00195   }
00196 
00197   std::string UTMUPS::EncodeZone(int zone, bool northp) {
00198     if (! (zone >= MINZONE && zone <= MAXZONE))
00199         throw GeographicErr("Zone " + str(zone) + " not in range [0, 60]");
00200     ostringstream os;
00201     if (zone != UPS)
00202       os << setfill('0') << setw(2) << zone;
00203     os << (northp ? 'N' : 'S');
00204     return os.str();
00205   }
00206 
00207   Math::real UTMUPS::UTMShift() throw() { return real(MGRS::utmNshift); }
00208 
00209 } // namespace GeographicLib

Generated on 21 May 2010 for GeographicLib by  doxygen 1.6.1