making final adjustments

Author: Luick Klippel

README.md

@@ -10,30 +10,29 @@ There are a few technologies available which offer accuracy of up to a few mm, b
 
 The aim of SDGPS is to find a cheap, accurate and easy to implement DGPS C++ lib solution. The accuracy the project is aiming for is 2-1 meters. The used DGPS technique is Code Range DGPS which corrects the pseudo range of each satellite. First the pseudo range correction is calculated by substracting the observed pseudo range from the calculated pseudo range (from ephemeris). If ephemeris data is available and the corrected pseudo range value is calculated, single point positioning is applied, to triangulate the final position.  
 
-
 ## Introduction to DGPS
 
-Differential GPS or DGPS makes use of a nearby base station which knows it's true position and calculates the difference in  position to send that correction via. any means of communication to it's clients, for example a rover which already has a GPS module on board which is accurate up to a few meters, with the corrections applied it can achieve accuracies of even a quarter of a meter, assuming it's in the range of the basestation.
+Differential GPS or DGPS makes use of a nearby base station which knows its true position and calculates the difference in position to send that correction via. any means of communication to its clients. For example a rover which already has a GPS module on board which is accurate up to a few meters. With the corrections applied it can achieve accuracies of even a quarter of a meter, assuming it's in the range of the basestation.
 
 ### RTK DGPS
 
-Real Time Kinematic makes use of the phase rotation as an indicator for the pseudo range. The basestation measures the phase rotation and divides it by the satellites carrier frequency which returns a time, which can be used to estimate the the atmospheric error. The achieved accuracy is extremely high.
+Real Time Kinematic makes use of the phase rotation as an indicator for the pseudo range. The basestation measures the phase rotation and divides it by the satellites carrier frequency which returns a time, which can be used to estimate the the atmospheric error. The achieved accuracy is very good.
 
 ### Position DGPS
 
 Position DGPS just uses the position difference as an correction value, so the basestation compares its lat/ lon to the known true lat/lon and sends the difference as an correction value to the rover.
 
-The only disadvantage is that, if the set of satellites changes, the correction value does not apply anymore. So both, the receiver and the client need the exact same sets of satellites or the result can get even worse.
+The only disadvantage is that, if the set of satellites changes, the correction value does not apply anymore. So both, the receiver and the client need the exact same sets of satellites or the result are inaccurate.
 
 ### Code Range DGPS
 
-Code Range DGPS takes the difference in pseudo range as correction value, so the basestation compares the difference between the observed pseudo range and actual true pseudo range and takes it as the correction value. As with the RTK DGPS the correction values are calculated for each satellite, which increases the usability dramatically. Another huge advantage is that it does not require any expensive receivers.
+Code Range DGPS takes the difference in pseudo range as a correction value, so the basestation compares the difference between the observed pseudo range and actual true pseudo range and uses it as the correction value. As with the RTK DGPS the correction values are calculated for each satellite, which increases the usability dramatically. Another huge advantage is that it does not require any expensive receivers.
 The only requirement for the receiver is that it supports raw data output, that can output ephemeris and raw pseudo range data.
 
 ## Available Correction algorithms
 
 Most of the GPS receivers already have several correction algorithms applied on there standard output, which mostly because they are relatively easy to calculate and behave linearly.
-Corrected biases are, for example the satellite clock bias such as the receiver's clocks bias. Also the ionosphere, troposphere do affect the results. Those values/ corrections are known and can be removed relatively easily, if not removed even state of the art receivers would only have an accuracy of a few meters.
+Corrected biases are for example the satellite clock bias, such as the receiver's clocks bias. Also the ionosphere, troposphere do affect the results. Those values/ corrections are known and can be removed relatively easily, if not removed even state of the art receivers would only have an accuracy of a few meters.
 
 # Technical realisation
 

bin/coreTest

@@ -6,5 +6,5 @@ CXX_DEFINES =
 
 CXX_INCLUDES = -I/usr/local/include -I/Users/luickklippel/Documents/projekte/simple-dgps/src/include -I/Users/luickklippel/Documents/projekte/cc.ublox.commsdsl/build/comms_champion/install/include -I/Users/luickklippel/Documents/projekte/cc.ublox.commsdsl/build/output/include
 
-CXX_FLAGS =  -std=c++11 -O3 -g -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -std=gnu++11
+CXX_FLAGS = -Wall -Wextra -g -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -std=gnu++11
 

build/CMakeFiles/CMakeOutput.log

@@ -6,5 +6,5 @@ CXX_DEFINES =
 
 CXX_INCLUDES = -I/usr/local/include -I/Users/luickklippel/Documents/projekte/simple-dgps/src/include -I/Users/luickklippel/Documents/projekte/cc.ublox.commsdsl/build/comms_champion/install/include -I/Users/luickklippel/Documents/projekte/cc.ublox.commsdsl/build/output/include
 
-CXX_FLAGS =  -std=c++11 -O3 -g -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -std=gnu++11
+CXX_FLAGS = -Wall -Wextra -g -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk -std=gnu++11
 

build/src/CMakeFiles/CommCore.dir/commCore.cpp.o

@@ -6,6 +6,8 @@ find_package( Boost 1.40 REQUIRED )
 message(STATUS "Boost version: ${Boost_VERSION}")
 include_directories( ${Boost_INCLUDE_DIR} )
 
+set (CMAKE_CXX_FLAGS "-Wall -Wextra")
+
 include_directories("${CMAKE_SOURCE_DIR}/src/include/")
 include_directories("${UBLOX_COMMDSL_PROJECT_PATH}/build/comms_champion/install/include/")
 include_directories("${UBLOX_COMMDSL_PROJECT_PATH}/build/output/include/")

build/src/CMakeFiles/CommCore.dir/flags.make

@@ -48,9 +48,6 @@ double calcTimeFromEpoch(double t, double t_ref)
 
 double calcEccentricAnomaly(ephemeris *ephem, double t_k)
 {
-  // Semi-major axis
-  int A = ephem->sqrtA*ephem->sqrtA;
-
   // Computed mean motion (rad/sec)
   double n_0 = sqrt(ephem->MU/(ephem->A*ephem->A*ephem->A));
 
@@ -77,7 +74,6 @@ latLonAltPos ecefToLatLonAlt(ecefPos ecef)
   latLonAltPos finalLatLonPos = { 0, 0, 0 };
   double zp, w2, w, r2, r, s2, c2, s, c, ss;
   double g, rg, rf, u, v, m, f, p, x, y, z;
-  double n, lat, lon, alt;
 
   x = ecef.x;
   y = ecef.y;
@@ -129,8 +125,6 @@ latLonAltPos ecefToLatLonAlt(ecefPos ecef)
 
 ecefPos latLonAltToEcef(latLonAltPos latlonAlt)
 {
-  double zp, w2, w, r2, r, s2, c2, s, c, ss;
-  double g, rg, rf, u, v, m, f, p, x, y, z;
   double n, lat, lon, alt;
 
   ecefPos ecef = { 0, 0, 0 };
@@ -340,8 +334,6 @@ double clacDeterminant(double **A, int rows)
   // Iterate for each element of first row
   for (int f = 0; f < rows; f++)
   {
-      // Getting Cofactor of A[0][f]
-      double **temp = getCofactor(A, 0, f, rows);
       D += sign * A[0][f] * clacDeterminant(A, rows - 1);
 
       // terms are to be added with alternate sign
@@ -361,9 +353,6 @@ double** calcAdjoint(double **A, int matrixArows)
   {
       for (int j=0; j<posMTrillatASize; j++)
       {
-          // Get cofactor of A[i][j]
-          double **temp = getCofactor(A, i, j, posMTrillatASize);
-
           // sign of adj[j][i] positive if sum of row
           // and column indexes is even.
           sign = ((i+j)%2==0)? 1: -1;
@@ -523,9 +512,5 @@ ecefPos trillatPosFromRange(satLocation finalSatPos, satRanges finalSatRanges)
   finalPos.y = finalECEF[1];
   finalPos.z = finalECEF[2];
 
-  for (int i = 0; i < 5; ++i)
-  {
-    std::cout << finalECEF[i] << std::endl;
-  }
   return finalPos;
 }

build/src/CMakeFiles/SimpleDGps.dir/flags.make

@@ -18,6 +18,35 @@ int main() {
   testMatrixA[2][1] = 8;
   testMatrixA[2][2] = 7;
 
+  ephemeris eph = {
+      797;
+      t_gd;
+      224;
+      t_oc;
+      a_f[2];
+      26560300;
+      -2.62555;
+      IODE2;
+      87.6875;
+      dn;
+      M_0;
+      C_uc;
+      e;
+      C_us;
+      sqrtA;
+      t_oe;
+      C_ic;
+      OMEGA_0;
+      OMEGA_E;
+      C_is;
+      i_0;
+      C_rc;
+      omega;
+      OMEGA_dot;
+      IODE3;
+      IDOT;
+  };
+
   std::cout << "transpose:" << std::endl;
   double **testTranspose = transpose2DimMatrix(testMatrixA, t, t);
   for (int i = 0; i < t; ++i)
@@ -72,5 +101,28 @@ int main() {
   cout << res.x << endl;
   cout << res.y << endl;
   cout << res.z << endl;
+
+  // basestation correction, required for correction
+  latLonAltPos baseStationPos;
+  baseStationPos.lat = 85.934710;
+  baseStationPos.lon = 17.747955;
+  baseStationPos.alt = 5;
+
+  // calculating range correction set
+  satRanges correctionRanges = calcSatRangeCorrection(testSatPos, baseStationPos, testPseudoRanges);
+  // applying correction to measured uncorrected pseudo ranges
+  satRanges correctedPseudoRanges = applyCorrectionOnPseudoRange(correctionRanges, testPseudoRanges);
+
+  // calculating position from corrected pseudo ranges
+  ecefPos resCorrected = trillatPosFromRange(testSatPos, correctedPseudoRanges);
+
+  std::cout << "Test corrected trillat:" << std::endl;
+  cout << resCorrected.x << endl;
+  cout << resCorrected.y << endl;
+  cout << resCorrected.z << endl;
+
+
+  ecefPos satPos = calcSatPos(ephemeris *ephem, double t);
+
   return 0;
 }