NavigationToolkit

Position Converters

Convert between 4 types of geographical coordinates systems.

1. Local tangent plane (also known as NED, ENU etc..) https://en.wikipedia.org/wiki/Local_tangent_plane_coordinates

2. Earth-Centered, Earth-Fixed (also known as ECEF) https://en.wikipedia.org/wiki/Earth-centered,_Earth-fixed_coordinate_system

3. Lla Coordinate System (latitude, longitude, altitude) https://en.wikipedia.org/wiki/Geographic_coordinate_system

4. Local Horizontal Coordinates (also known as polar position, or Azimuth, Elevation, Range)

Usage

Convert Lla-Position to ECEF

var pc = new PositionConverter();
var lat = 32.1882286;
var lon = 34.8963593;
var alt = 500.00;
LlaPosition geo = new LlaPosition(lat, lon, alt);
EcefPosition ecef = pc.LlaToEcef(Lla);
Console.WriteLine(ecef);

// Prints
// X: 4431798.222675216, Y: 3091246.629098461, Z: 3378380.366578883

Convert two Lla-position points to Local tangent plane

var pc = new PositionConverter();
LlaPosition origin = new LlaPosition(-51.736538, -59.430458, 0);
LlaPosition target = new LlaPosition(-51.687572, -60.158750, 3000);
LtpPosition geoToLtp = pc.LlaToLtp(target, origin);
Console.WriteLine(geoToLtp.ToStringNed());
Console.WriteLine(geoToLtp.ToStringEnu());

// Prints
// North: 5199.166000297293, East: -50387.38398064566, Down: -2799.350897683762
// East: -50387.38398064566, North: 5199.166000297293, Up: 2799.350897683762

Convert two Lla-position points to Azimuth elevation distance

var pc = new PositionConverter();
LlaPosition origin = new LlaPosition(4.682880, -7.965253, 0);
LlaPosition target = new LlaPosition(4.782880, -7.985253, 3000);
var azimuthElevationDistance = pc.LlaToAed(origin,target );
Console.WriteLine(azimuthElevationDistance);

// Prints
// Azimuth:348.6549994285944, Elevation:14.840890085414388,Distance:11673.341221811483 

Convert local tangent plane to ECEF

var pv = new PositionConverter();
LlaPosition origin = new LlaPosition(4.682880, -7.965253, 0);
LtpPosition ltpPosition = new LtpPosition(100.0, 200.0, 300.0);
EcefPosition ecef = pv.LtpToEcef(ltpPosition, origin);
Console.WriteLine(ecef);

// Prints
// X: 6295380.62181266, Y: -880663.1908122151, Z: 517316.47438104654

Image credits:

• https://standards.sedris.org
• https://ww2.mathworks.cn
• http://jhnet.co.uk
• https://www.timeanddate.com