public void EqualityTest_2(double e, double n, double h, double e2, double n2, double h2, bool e1)
{
EastingNorthing k = new EastingNorthing(e, n, h);
EastingNorthing k2 = new EastingNorthing(e2, n2, h2);
Assert.AreNotEqual(k, k2);
}
/// <summary>
/// Performs an OSGB36/ODN to ETRS89 datum transformation. Accuracy is approximately 10 centimeters.
/// Whilst very accurate this method is much slower than the Helmert transformation.
/// </summary>
public static LatitudeLongitude OsgbToEtrs89(Osgb36 coordinates, OstnVersionEnum ostnVersion = OstnVersionEnum.OSTN15)
{
//calculate shifts from OSGB36 point
double errorN = double.MaxValue;
double errorE = double.MaxValue;
EastingNorthing enCoordinates = null;
Shifts shiftsA = GetShifts(coordinates, ostnVersion);
//0.0001 error meters
int iter = 0;
while ((errorN > 0.0001 || errorE > 0.0001) && iter < 10)
{
enCoordinates = new EastingNorthing(coordinates.Easting - shiftsA.Se, coordinates.Northing - shiftsA.Sn);
Shifts shiftsB = GetShifts(enCoordinates, ostnVersion);
errorE = Math.Abs(shiftsA.Se - shiftsB.Se);
errorN = Math.Abs(shiftsA.Sn - shiftsB.Sn);
shiftsA = shiftsB;
iter++;
}
return(Convert.ToLatitudeLongitude(new Wgs84(), new BritishNationalGrid(), enCoordinates));
}
public void EqualityTest(double e, double n, double h, bool e1)
{
EastingNorthing k = new EastingNorthing(e, n, h);
EastingNorthing k2 = new EastingNorthing(e, n, h);
Assert.AreEqual(k, k2);
}
public void ToString_Test()
{
EastingNorthing k = new EastingNorthing(10, 20, 30);
string outcome = k.ToString();
string expected = "Easting:10 Northing:20 Height:30";
Assert.AreEqual(expected, outcome);
}
private static Osgb36 Etrs89ToOsgb(EastingNorthing coordinates, double ellipsoidHeight, OstnVersionEnum ostnVersion = OstnVersionEnum.OSTN15)
{
Shifts shifts = GetShifts(coordinates, ostnVersion);
double easting = coordinates.Easting + shifts.Se;
double northing = coordinates.Northing + shifts.Sn;
double height = ellipsoidHeight - shifts.Sg;
return(new Osgb36(easting, northing, height, shifts.GeoidDatum));
}
public void To_OSGB36(double a, double b, double c, double e, double f, double g)
{
ICoodrinateSupport q = new CoordinateSupport();
ToOSGB36 k = new ToOSGB36(Shifts_, q);
var Outcome = k.Calculate(a, b, c);
EastingNorthing Expected = new EastingNorthing(e, f, g);
Assert.AreEqual(Expected, Outcome);
}
/// <summary>
/// Calling this method will convert from the passed value to the OSGB36
/// </summary>
/// <param name="pCoordinate">The latitude and longtitude to be converted </param>
/// <returns>The location as a OSGB36 coordinate</returns>
public ICoordinate Calculate(ICoordinate pCoordinate)
{
if (pCoordinate.GetType() != typeof(EastingNorthing))
{
throw new CoordinateTypeException("the wrong coordinate type has been passed");
}
else
{
EastingNorthing p = (EastingNorthing)pCoordinate;
return(Calculate(p.Easting, p.Northing, p.Height));
}
}
public void Test_ToLatLon_AsCoodrinate(double a, double b, double c, double e, double f, double g)
{
ICoodrinateSupport q = new CoordinateSupport();
ToLatLon k = new ToLatLon(Shifts_, q);
EastingNorthing n = new EastingNorthing(f, e, g);
var Outcome = (LatLon)k.Calculate(n);
LatLon Expected = new LatLon(a, b, c);
Assert.AreEqual(Expected.Latitude, Outcome.Latitude, 0.01);
Assert.AreEqual(Expected.Longtitude, Outcome.Longtitude, 0.01);
Assert.AreEqual(Expected.Height, Outcome.Height, 0.01);
}
/// <summary>
/// Calling this method will convert from the passed value to the OSGB36 convertor
/// </summary>
/// <param name="pHorizontal">The point on the horizontal axis (easting or latitude)</param>
/// <param name="pVertical">The point on the vertical axis (northing or longtitude)</param>
/// <param name="pHeight">The height to be converted</param>
/// <returns>The location as a OSGB36 coordinate</returns>
private ICoordinate InternalCalculate(double pHorizontal, double pVertical, double pHeight)
{
double lat = mCoordinateSupport.DegreeesToRadians(pVertical);
double lon = mCoordinateSupport.DegreeesToRadians(pHorizontal);
double ht = pHeight;
double a = OSGB35Constants.a;
a *= OSGB35Constants.f0;
double b = OSGB35Constants.b;
b *= OSGB35Constants.f0;
double n = (a - b) / (a + b);
double e2 = ((a * a) - (b * b)) / (a * a);
double nu = (a / Math.Pow(1 - e2 * Math.Pow(Math.Sin(lat), 2.0), 0.5));
double rho = ((a * (1 - e2)) / Math.Pow(1 - e2 * Math.Pow(Math.Sin(lat), 2.0), 1.5));
double n2 = (nu / rho) - 1;
double dLat = lat - OSGB35Constants.lat0; // difference in latitude
double sLat = lat + OSGB35Constants.lat0; // sum of latitude
double M = MeridianArc.ComputeMeridanArc(dLat, sLat, n, b);
double P = lon - OSGB35Constants.lon0; // difference in longitude
// The following are taken from [1] pp10-11
double I = M + OSGB35Constants.n0;
double II = (nu / 2) * Math.Sin(lat) * Math.Cos(lat);
double III = (nu / 24) * Math.Sin(lat) * Math.Pow(Math.Cos(lat), 3.0) * (5 - Math.Pow(Math.Tan(lat), 2.0) + (9 * n2));
double IIIA = (nu / 720) * Math.Sin(lat) * Math.Pow(Math.Cos(lat), 5.0) *
(61 - (58 * Math.Pow(Math.Tan(lat), 2.0)) + Math.Pow(Math.Tan(lat), 4.0));
double IV = nu * Math.Cos(lat);
double V = (nu / 6) * Math.Pow(Math.Cos(lat), 3.0) * ((nu / rho) - Math.Pow(Math.Tan(lat), 2.0));
double VI = (nu / 120) * Math.Pow(Math.Cos(lat), 5.0) * (5 - (18 * Math.Pow(Math.Tan(lat), 2.0)) +
Math.Pow(Math.Tan(lat), 4.0) + (14 * n2) - (58 * Math.Pow(Math.Tan(lat), 2.0) * n2));
double y = I + (Math.Pow(P, 2.0) * II) + (Math.Pow(P, 4.0) * III) + (Math.Pow(P, 6.0) * IIIA);
double x = OSGB35Constants.e0 + (P * IV) + (Math.Pow(P, 3.0) * V) + (Math.Pow(P, 5.0) * VI);
Shift s = (Shift)mShifts.CalculateShift(x, y);
double lLat = x + s.Easting;
double lLon = y + s.Northing;
double lHeight = pHeight - s.Height;
EastingNorthing x1 = new EastingNorthing(lLat, lLon, lHeight);
return(x1);
}
public static void Example()
{
Console.WriteLine("-- Latitude/ Longitude to Easting/ Northing --");
LatitudeLongitude latLong = new LatitudeLongitude(51.469886, -3.1636964);
Console.WriteLine("INPUT");
Console.WriteLine($"Latitude: {latLong.Latitude}");
Console.WriteLine($"Longitude: {latLong.Longitude}");
Cartesian cartesian = Convert.ToCartesian(new Wgs84(), latLong);
Cartesian bngCartesian = Transform.Etrs89ToOsgb36(cartesian);
EastingNorthing bngEN = Convert.ToEastingNorthing(new Airy1830(), new BritishNationalGrid(), bngCartesian);
Console.WriteLine("OUTPUT");
Console.WriteLine($"Easting: {bngEN.Easting}");
Console.WriteLine($"Northing: {bngEN.Northing}");
Console.WriteLine();
}
public static void Examples()
{
Console.WriteLine("-- OS Map reference --");
// Convert to Osgb36 coordinates by creating a new object passing
// in the EastingNorthing object to the constructor.
EastingNorthing eastingNorthing = new EastingNorthing(319267, 175189);
Console.WriteLine("INPUT");
Console.WriteLine($"Easting: {eastingNorthing.Easting}");
Console.WriteLine($"Northing: {eastingNorthing.Northing}");
Osgb36 osgb36EN = new Osgb36(eastingNorthing);
string mapReference = osgb36EN.MapReference;
Console.WriteLine("OUTPUT");
Console.WriteLine($"Map reference: {mapReference}");
Console.WriteLine();
}
/// <summary>
/// Method to convert from Easting Northing coordinates to Latitude Longitude coordinates.
/// </summary>
/// <returns>The latitude longitude.</returns>
/// <param name = "ellipsoid"></param>
/// <param name="projection">Projection.</param>
/// <param name="coordinates">Coordinates.</param>
public static LatitudeLongitude ToLatitudeLongitude(Ellipsoid ellipsoid, Projection projection, EastingNorthing coordinates)
{
double M;
double N = coordinates.Northing;
double E = coordinates.Easting;
//from OS Guide
//constants needed are a Semi-Major Axis , b , e2 , N0 , E0 , F0 ,φ0 , and λ0
double a = ellipsoid.SemiMajorAxis;
double b = ellipsoid.SemiMinorAxis;
double e2 = ellipsoid.EccentricitySquared;
double F0 = projection.ScaleFactor;
double lat0 = ToRadians(projection.TrueOriginLatitude);
double lon0 = ToRadians(projection.TrueOriginLongitude);
double E0 = projection.TrueOriginEasting;
double N0 = projection.TrueOriginNorthing;
double lat = ((N - N0) / (a * F0)) + lat0;
//check for error and reiterate as required
int loopCount = 0;
do
{
M = CalculateM(lat, lat0, a, b, F0);
lat += ((N - N0 - M) / (a * F0));
loopCount++;
} while (!IsNearlyZero(N - N0 - M, 1e-16) && loopCount < 10);
double v = a * F0 * Math.Pow((1 - e2 * Math.Pow(Math.Sin(lat), 2)), -0.5);
double p = a * F0 * (1 - e2) * Math.Pow((1 - e2 * Math.Pow(Math.Sin(lat), 2)), -1.5);
double n2 = (v / p) - 1;
double VII = Math.Tan(lat) / (2 * p * v);
double VIIIa = Math.Tan(lat) / (24 * p * Math.Pow(v, 3));
double VIIIb = 5 + (3 * Math.Pow(Math.Tan(lat), 2)) + n2 - 9 * (Math.Pow(Math.Tan(lat), 2)) * n2;
double VIII = VIIIa * VIIIb;
double IXa = Math.Tan(lat) / (720 * p * Math.Pow(v, 5));
double IXb = 61 + (90 * Math.Pow(Math.Tan(lat), 2)) + (45 * Math.Pow(Math.Tan(lat), 4));
double IX = IXa * IXb;
double X = MathEx.Secant(lat) / v;
double XIa = MathEx.Secant(lat) / (6 * Math.Pow(v, 3));
double XIb = v / p + (2 * Math.Pow(Math.Tan(lat), 2));
double XI = XIa * XIb;
double XIIa = MathEx.Secant(lat) / (120 * Math.Pow(v, 5));
double XIIb = 5 + (28 * Math.Pow(Math.Tan(lat), 2)) + (24 * Math.Pow(Math.Tan(lat), 4));
double XII = XIIa * XIIb;
double XIIAa = MathEx.Secant(lat) / (5040 * Math.Pow(v, 7));
double XIIAb = 61 + (662 * Math.Pow(Math.Tan(lat), 2)) + (1320 * Math.Pow(Math.Tan(lat), 4)) + (720 * Math.Pow(Math.Tan(lat), 6));
double XIIA = XIIAa * XIIAb;
lat = lat - VII * Math.Pow(E - E0, 2) + VIII * Math.Pow(E - E0, 4) - IX * Math.Pow(E - E0, 6);
double lon = lon0 + X * (E - E0) - XI * Math.Pow(E - E0, 3) + XII * Math.Pow(E - E0, 5) - XIIA * Math.Pow(E - E0, 7);
return(new LatitudeLongitude(ToDegrees(lat), ToDegrees(lon)));
}
public static Cartesian ToCartesian(Ellipsoid ellipsoid, Projection projection, EastingNorthing coordinates)
{
LatitudeLongitude latLongCoordinates = ToLatitudeLongitude(
ellipsoid,
projection,
coordinates);
return(ToCartesian(ellipsoid, latLongCoordinates));
}
private static Shifts GetShifts(EastingNorthing coordinates, OstnVersionEnum ostnVersion)
{
//See OS Document: Transformations and OSGM02/OSGM15 user guide chapter 3
Dictionary <int, OstnDataRecord> ostnData = GetOstnData(ostnVersion);
List <int> recordNumbers = new List <int>();
OstnDataRecord[] records = new OstnDataRecord[4];
//determine record numbers
int eastIndex = (int)(coordinates.Easting / 1000.0);
int northIndex = (int)(coordinates.Northing / 1000.0);
double x0 = eastIndex * 1000;
double y0 = northIndex * 1000;
//work out the four records
recordNumbers.Add(CalculateRecordNumber(eastIndex, northIndex));
recordNumbers.Add(CalculateRecordNumber(eastIndex + 1, northIndex));
recordNumbers.Add(CalculateRecordNumber(eastIndex + 1, northIndex + 1));
recordNumbers.Add(CalculateRecordNumber(eastIndex, northIndex + 1));
// Get the corresponding records from the data dictionary
for (int index = 0; index < 4; index++)
{
records[index] = ostnData[recordNumbers[index]];
}
//populate the properties
double se0 = System.Convert.ToDouble(records[0].ETRS89_OSGB36_EShift);
double se1 = System.Convert.ToDouble(records[1].ETRS89_OSGB36_EShift);
double se2 = System.Convert.ToDouble(records[2].ETRS89_OSGB36_EShift);
double se3 = System.Convert.ToDouble(records[3].ETRS89_OSGB36_EShift);
double sn0 = System.Convert.ToDouble(records[0].ETRS89_OSGB36_NShift);
double sn1 = System.Convert.ToDouble(records[1].ETRS89_OSGB36_NShift);
double sn2 = System.Convert.ToDouble(records[2].ETRS89_OSGB36_NShift);
double sn3 = System.Convert.ToDouble(records[3].ETRS89_OSGB36_NShift);
double sg0 = System.Convert.ToDouble(records[0].ETRS89_ODN_HeightShift);
double sg1 = System.Convert.ToDouble(records[1].ETRS89_ODN_HeightShift);
double sg2 = System.Convert.ToDouble(records[2].ETRS89_ODN_HeightShift);
double sg3 = System.Convert.ToDouble(records[3].ETRS89_ODN_HeightShift);
double dx = coordinates.Easting - x0;
double dy = coordinates.Northing - y0;
double t = dx / 1000.0;
double u = dy / 1000.0;
Shifts shifts = new Shifts
{
Se = (1 - t) * (1 - u) * se0 + t * (1 - u) * se1 + t * u * se2 + (1 - t) * u * se3,
Sn = (1 - t) * (1 - u) * sn0 + t * (1 - u) * sn1 + t * u * sn2 + (1 - t) * u * sn3,
Sg = (1 - t) * (1 - u) * sg0 + t * (1 - u) * sg1 + t * u * sg2 + (1 - t) * u * sg3,
GeoidDatum = (Osgb36GeoidDatum)System.Convert.ToInt32(records[0].Height_Datum_Flag)
};
return(shifts);
}
/// <summary>
/// Performs an ETRS89 to OSGB36/ODN datum transformation. Accuracy is approximately 10 centimeters.
/// Whilst very accurate this method is much slower than the Helmert transformation.
/// </summary>
public static Osgb36 Etrs89ToOsgb(LatitudeLongitude coordinates)
{
EastingNorthing enCoordinates = Convert.ToEastingNorthing(new Grs80(), new BritishNationalGrid(), coordinates);
return(Etrs89ToOsgb(enCoordinates, coordinates.EllipsoidalHeight));
}
private static Osgb36 Etrs89ToOsgb(EastingNorthing coordinates, double ellipsoidHeight)
{
Stream dataStream = GetEmbeddedOSTN02();
TextReader tr = new StreamReader(dataStream);
List <int> recordNumbers = new List <int>();
string[] records = new string[4];
//determine record numbers
int eastIndex = (int)(coordinates.Easting / 1000.0);
int northIndex = (int)(coordinates.Northing / 1000.0);
double x0 = eastIndex * 1000;
double y0 = northIndex * 1000;
//work out the four records
recordNumbers.Add(CalculateRecordNumber(eastIndex, northIndex));
recordNumbers.Add(CalculateRecordNumber(eastIndex + 1, northIndex));
recordNumbers.Add(CalculateRecordNumber(eastIndex + 1, northIndex + 1));
recordNumbers.Add(CalculateRecordNumber(eastIndex, northIndex + 1));
//get records from the data file
int recordsFound = 0;
while (recordsFound < 4)
{
string csvRecord = tr.ReadLine();
for (int index = 0; index < 4; index++)
{
if (csvRecord != null && !csvRecord.StartsWith(recordNumbers[index].ToString().Trim() + ",", StringComparison.Ordinal))
{
continue;
}
//don't use add as we need to keep these in same order as record numbers
records[index] = csvRecord;
recordsFound++;
}
}
//populate the properties
string[] fields0 = records[0].Split(",".ToCharArray());
string[] fields1 = records[1].Split(",".ToCharArray());
string[] fields2 = records[2].Split(",".ToCharArray());
string[] fields3 = records[3].Split(",".ToCharArray());
double se0 = System.Convert.ToDouble(fields0[3]);
double se1 = System.Convert.ToDouble(fields1[3]);
double se2 = System.Convert.ToDouble(fields2[3]);
double se3 = System.Convert.ToDouble(fields3[3]);
double sn0 = System.Convert.ToDouble(fields0[4]);
double sn1 = System.Convert.ToDouble(fields1[4]);
double sn2 = System.Convert.ToDouble(fields2[4]);
double sn3 = System.Convert.ToDouble(fields3[4]);
double sg0 = System.Convert.ToDouble(fields0[5]);
double sg1 = System.Convert.ToDouble(fields1[5]);
double sg2 = System.Convert.ToDouble(fields2[5]);
double sg3 = System.Convert.ToDouble(fields3[5]);
double dx = coordinates.Easting - x0;
double dy = coordinates.Northing - y0;
double t = dx / 1000.0;
double u = dy / 1000.0;
double se = (1 - t) * (1 - u) * se0 + t * (1 - u) * se1 + t * u * se2 + (1 - t) * u * se3;
double sn = (1 - t) * (1 - u) * sn0 + t * (1 - u) * sn1 + t * u * sn2 + (1 - t) * u * sn3;
double sg = (1 - t) * (1 - u) * sg0 + t * (1 - u) * sg1 + t * u * sg2 + (1 - t) * u * sg3;
Osgb36GeoidDatum geoidDatum = (Osgb36GeoidDatum)System.Convert.ToInt32(fields0[6]);
double easting = coordinates.Easting + se;
double northing = coordinates.Northing + sn;
double height = ellipsoidHeight - sg;
return(new Osgb36(easting, northing, height, geoidDatum));
}
