[GIS] Using proj string in java code

coordinate systemgdaljavaogr

I want to do projection from UTM/oblique mercator CRS to WGS84. And I know the solution to use a proj.4 string in commandline like+proj=omerc +lat_0=51.4 +lonc=7 +alpha=-10 +k=1 +x_0=0 +y_0=0 +gamma=0 +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs

However, I wonder if there is a way to do such transformation using plain code. I have configured the gdal jar for my eclipse and want to use the java bindings to do such transformation. From the OGR projection tutorial,I know how to define a Geographic Coordinate System and projected Coordinate Sytem with OGRSpatialReference class. I know how to define a transformation using OGRCoordinateTransformation class. But the only thing missing there is the possibility to customize my source UTM. I don't know how to set the lon,lat of my orgin point. I also don't know how to set the oblique angle. There seems to be no such pre-built method in the classes.

Anyone can give me some hints?

Best Answer

You can use proj.4 java bindings like GeoAPI and Proj4j. If you are familar with threads, process programming and piped streaming you can use a direct OS call whith your common proj.4 params.

Proj4j looks like this and have a look in Martin Davis unit test repository :

package org.osgeo.proj4j;

import junit.textui.TestRunner;

/**
 * Tests from the PROJ4 testvarious file.
 * 
 * @author Martin Davis
 *
 */
public class Proj4VariousTest extends BaseCoordinateTransformTest
{ 
  public static void main(String args[]) {
    TestRunner.run(Proj4VariousTest.class);
  }

  public Proj4VariousTest(String name) { super(name); }

  public void testRawEllipse()
  {
    checkTransform(
        "+proj=latlong +ellps=clrk66", p("79d58'00.000W 37d02'00.000N"), 
        "+proj=latlong +ellps=bessel", p("79d58'W 37d2'N"), 0.01 );
    checkTransform(
        "+proj=latlong +ellps=clrk66", p("79d58'00.000\"W 36d58'00.000\"N"), 
        "+proj=latlong +ellps=bessel", p("79d58'W 36d58'N"), 0.01 );
  }

  public void testNAD27toRawEllipse()
  {
    checkTransform(
        "+proj=latlong +datum=NAD27", p("79d00'00.000\"W 35d00'00.000\"N"), 
        "+proj=latlong +ellps=bessel", p("79dW 35dN"), 0.01 );
  }

  public void test3ParamApproxSameEllipsoid()
  {
    checkTransform(
        "+proj=latlong +ellps=bessel +towgs84=5,0,0", p("0d00'00.000W 0d00'00.000N"), 
        "+proj=latlong +ellps=bessel +towgs84=1,0,0", p("0dE  0dN 4.000"), 1e-5 );
    checkTransform(
        "+proj=latlong +ellps=bessel +towgs84=5,0,0", p("79d00'00.000W 45d00'00.000N 0.0"), 
        "+proj=latlong +ellps=bessel +towgs84=1,0,0", p("78d59'59.821W  44d59'59.983N 0.540"), 1e-5 );
  }
  public void test3ParamToRawSameEllipsoid()
  {
    checkTransform(
        "+proj=latlong +ellps=bessel +towgs84=5,0,0", p("0d00'00.000W 0d00'00.000N"), 
        "+proj=latlong +ellps=bessel", p("0dE  0dN 4.000"), 1e-5 );
  }

  public void FAIL_test3ParamToRawSameEllipsoid2()
  {
    // fails - not sure why, possibly missing towgs not handled in same way as PROJ4?
    checkTransform(
        "+proj=latlong +ellps=bessel +towgs84=5,0,0", p("79d00'00.000W 45d00'00.000N 0.0"), 
        "+proj=latlong +ellps=bessel", p("79dW  45dN 0.000"), 1e-5 );
  }

  public void testStere()
  {
    checkTransform(
        "+proj=latlong +datum=WGS84", p("105 40"), 
        "+proj=stere +lat_0=90 +lon_0=0 +lat_ts=70 +datum=WGS84", p("5577808.93 1494569.40 0.00"), 1e-2 );
  }
  public void testStereWithout_lat_ts()
  {
    checkTransform(
        "+proj=latlong +datum=WGS84", p("20 45"), 
        "+proj=stere +lat_0=40 +lon_0=10  +datum=WGS84", p("789468.08 602385.33 0.00"), 1e-2 );
  }
  public void testSTS()
  {
    checkTransform(
        "+proj=latlong +datum=WGS84", p("4.897000 52.371000"), 
        "+proj=kav5 +ellps=WGS84 +units=m", p("383646.09  5997047.89"), 1e-2 );
    checkTransform(
        "+proj=kav5 +ellps=WGS84 +units=m", p("383646.088858 5997047.888175"),
        "+proj=latlong +datum=WGS84", p("4d53'49.2E  52d22'15.6N"), 
        1e-5 );
  }
  // disabled - gamma param not implemented
  public void XXX_testRSOBorneo()
  {
    checkTransform(
        "+proj=latlong +a=6377298.556 +rf=300.8017", p("116d2'11.12630 5d54'19.90183"), 
        "+proj=omerc +a=6377298.556 +rf=300.8017 +lat_0=4 +lonc=115 +alpha=53d18'56.9537 +gamma=53d7'48.3685  +k_0=0.99984 +x_0=590476.87 +y_0=442857.65", 
        p("704570.40  653979.68"), 1e-2 );
  }
  public void FAIL_testPconic()
  {
    checkTransform(
        "+proj=latlong +datum=WGS84", p("-70.4 -23.65"), 
        "+proj=pconic  +units=m +lat_1=20n +lat_2=60n +lon_0=60W +datum=WGS84", p("-2240096.40  -6940342.15"),
        1e-2 );
    // Known failure case
    checkTransform(
        "+proj=pconic  +units=m +lat_1=20n +lat_2=60n +lon_0=60W +datum=WGS84", p("-2240096.40  -6940342.15"),
        "+proj=latlong +datum=WGS84", p("-70.4 -23.65"), 
        1e-2 );
  }

}
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