//
// RADRnav.java
//
/*
This source file is part of the edu.wisc.ssec.mcidas package and is
Copyright (C) 1998 - 2017 by Tom Whittaker, Tommy Jasmin, Tom Rink,
Don Murray, James Kelly, Bill Hibbard, Dave Glowacki, Curtis Rueden
and others.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA
*/
package edu.wisc.ssec.mcidas;
/**
* Navigation class for Radar (RADR) type nav. This code was modified
* from the original FORTRAN code (nvxradr.dlm) on the McIDAS system. It
* only supports latitude/longitude to line/element transformations (LL)
* and vice/versa. Transform to 'XYZ' not implemented.
* @see
* McIDAS Programmer's Manual
*
* @author Don Murray
*/
public final class RADRnav extends AREAnav
{
private boolean isEastPositive = true;
final double EARTH_RADIUS=6371.23; // earth equatorial radius (km)
final int MISS = McIDASUtil.MCMISSING;
int itype;
double xrow;
double xcol;
double xlat;
double xlon;
double xrot;
double xblat;
double xblon;
/**
* Set up for the real math work. Must pass in the int array
* of the RADR nav 'codicil'.
*
* @param iparms the nav block from the image file
* @throws IllegalArgumentException
* if the nav block is not a RADR type.
*/
public RADRnav (int[] iparms)
throws IllegalArgumentException
{
/* No longer needed. Kept for consistency with nvxradr.dlm
if (ifunc != 1)
{
if (iparms[0] == XY ) itype = 1;
if (iparms[0] == LL ) itype = 2;
return;
}
*/
if (iparms[0] != RADR )
throw new IllegalArgumentException("Invalid navigation type" +
iparms[0]);
itype = 2;
xrow = iparms[1];
xcol = iparms[2];
xlat = McIDASUtil.integerLatLonToDouble(iparms[3]);
xlon = McIDASUtil.integerLatLonToDouble(iparms[4]);
double xspace = iparms[5]/1000.;
double yspace = xspace;
if (iparms[7] != 0 && iparms[7] != MISS)
yspace = iparms[7]/1000.;
xrot = -DEGREES_TO_RADIANS*iparms[6]/1000.;
xblat = EARTH_RADIUS*DEGREES_TO_RADIANS/xspace;
xblon = EARTH_RADIUS*DEGREES_TO_RADIANS/yspace;
}
/** converts from satellite coordinates to latitude/longitude
*
* @param linele array of line/element pairs. Where
* linele[indexLine][] is a 'line' and
* linele[indexEle][] is an element. These are in
* 'file' coordinates (not "image" coordinates.)
*
* @return latlon[][] array of lat/long pairs. Output array is
* latlon[indexLat][] of latitudes and
* latlon[indexLon][] of longitudes.
*
*/
public double[][] toLatLon(double[][] linele)
{
double xldif;
double xedif;
double xdis;
double xangl;
double xange;
double ylat;
double ylon;
int number = linele[0].length;
//double[][] latlon = new double[2][number];
// Convert array to Image coordinates for computations
double[][] imglinele = areaCoordToImageCoord(linele);
double[][] latlon = imglinele;
for (int point=0; point < number; point++)
{
xldif = xrow - imglinele[indexLine][point];
xedif = xcol - imglinele[indexEle][point];
xdis = Math.sqrt(xldif*xldif + xedif*xedif);
if (xdis > 0.001)
{
xangl = Math.atan2(xldif, xedif) - 90.*DEGREES_TO_RADIANS;
xange = Math.atan2(xldif, xedif) + 90.*DEGREES_TO_RADIANS;
xldif = xdis*Math.cos(xrot+xangl);
xedif = xdis*Math.sin(xrot+xange);
}
ylat = xlat + xldif/xblat;
ylon = xlon + xedif/xblon/Math.cos(ylat* DEGREES_TO_RADIANS);
// transform from McIDAS coordinates
if (isEastPositive) ylon = -ylon;
latlon[indexLat][point] = ylat;
latlon[indexLon][point] = ylon;
} // end point for loop
return latlon;
}
/**
* toLinEle converts lat/long to satellite line/element
*
* @param latlon array of lat/long pairs. Where latlon[indexLat][]
* are latitudes and latlon[indexLon][] are longitudes.
*
* @return linele[][] array of line/element pairs. Where
* linele[indexLine][] is a line and linele[indexEle][]
* is an element. These are in 'file' coordinates
* (not "image" coordinates);
*/
public double[][] toLinEle(double[][] latlon)
{
double zlat;
double zlon;
double xrlon;
double xrlat;
double xldif;
double xedif;
double xdis;
double xangl;
double xange;
int number = latlon[0].length;
double[][] linele = new double[2][number];
for (int point=0; point < number; point++)
{
if (Double.isNaN(latlon[indexLat][point]) ||
Double.isNaN(latlon[indexLon][point])) {
linele[indexLine][point] = Float.NaN;
linele[indexEle][point] = Float.NaN;
continue;
}
zlat = latlon[indexLat][point];
// transform to McIDAS (west positive longitude) coordinates
zlon = isEastPositive
? -latlon[indexLon][point]
: latlon[indexLon][point];
if (zlon > 180) zlon -= 360;
if (zlon < -180) zlon += 360;
xrlon = zlon - xlon;
xrlat = zlat - xlat;
xldif = xblat*xrlat;
xedif = xrlon*xblon*Math.cos(zlat*DEGREES_TO_RADIANS);
xdis = Math.sqrt(xldif*xldif + xedif*xedif);
if (xdis > .001)
{
xangl = Math.atan2(xldif, xedif)-90*DEGREES_TO_RADIANS;
xange = Math.atan2(xldif, xedif)+90*DEGREES_TO_RADIANS;
xldif = xdis*Math.cos(-xrot+xangl);
xedif = xdis*Math.sin(-xrot+xange);
}
linele[indexLine][point] = xrow - xldif;
linele[indexEle][point] = xcol - xedif;
} // end point loop
// Return in 'File' coordinates
return imageCoordToAreaCoord(linele, linele);
}
/** converts from satellite coordinates to latitude/longitude
*
* @param linele array of line/element pairs. Where
* linele[indexLine][] is a 'line' and
* linele[indexEle][] is an element. These are in
* 'file' coordinates (not "image" coordinates.)
*
* @return latlon[][] array of lat/long pairs. Output array is
* latlon[indexLat][] of latitudes and
* latlon[indexLon][] of longitudes.
*
*/
public float[][] toLatLon(float[][] linele)
{
double xldif;
double xedif;
double xdis;
double xangl;
double xange;
double ylat;
double ylon;
int number = linele[0].length;
/*
float[][] latlon = new float[2][number];
float[] lats = latlon[indexLat];
float[] lons = latlon[indexLon];
*/
// Convert array to Image coordinates for computations
float[][] imglinele = areaCoordToImageCoord(linele);
float[][] latlon = imglinele;
float[] lats = latlon[indexLat];
float[] lons = latlon[indexLon];
float[] lines = imglinele[indexLine];
float[] eles = imglinele[indexEle];
for (int point=0; point < number; point++)
{
xldif = xrow - lines[point];
xedif = xcol - eles[point];
xdis = Math.sqrt(xldif*xldif + xedif*xedif);
if (xdis > 0.001)
{
xangl = Math.atan2(xldif, xedif) - 90.*DEGREES_TO_RADIANS;
xange = Math.atan2(xldif, xedif) + 90.*DEGREES_TO_RADIANS;
xldif = xdis*Math.cos(xrot+xangl);
xedif = xdis*Math.sin(xrot+xange);
}
ylat = xlat + xldif/xblat;
ylon = xlon + xedif/xblon/Math.cos(ylat* DEGREES_TO_RADIANS);
// transform from McIDAS coordinates
if (isEastPositive) ylon = -ylon;
lats[point] = (float) ylat;
lons[point] = (float) ylon;
} // end point for loop
return latlon;
}
/**
* toLinEle converts lat/long to satellite line/element
*
* @param latlon array of lat/long pairs. Where latlon[indexLat][]
* are latitudes and latlon[indexLon][] are longitudes.
*
* @return linele[][] array of line/element pairs. Where
* linele[indexLine][] is a line and linele[indexEle][]
* is an element. These are in 'file' coordinates
* (not "image" coordinates);
*/
public float[][] toLinEle(float[][] latlon)
{
double zlat;
double zlon;
double xrlon;
double xrlat;
double xldif;
double xedif;
double xdis;
double xangl;
double xange;
int number = latlon[0].length;
float[][] linele = new float[2][number];
float[] lines = linele[indexLine];
float[] eles = linele[indexEle];
float[] lats = latlon[indexLat];
float[] lons = latlon[indexLon];
for (int point=0; point < number; point++)
{
if (Float.isNaN(lats[point]) ||
Float.isNaN(lons[point])) {
linele[indexLine][point] = Float.NaN;
linele[indexEle][point] = Float.NaN;
continue;
}
zlat = lats[point];
// transform to McIDAS (west positive longitude) coordinates
zlon = isEastPositive
? -lons[point]
: lons[point];
if (zlon > 180) zlon -= 360;
if (zlon < -180) zlon += 360;
xrlon = zlon - xlon;
xrlat = zlat - xlat;
xldif = xblat*xrlat;
xedif = xrlon*xblon*Math.cos(zlat*DEGREES_TO_RADIANS);
xdis = Math.sqrt(xldif*xldif + xedif*xedif);
if (xdis > .001)
{
xangl = Math.atan2(xldif, xedif)-90*DEGREES_TO_RADIANS;
xange = Math.atan2(xldif, xedif)+90*DEGREES_TO_RADIANS;
xldif = xdis*Math.cos(-xrot+xangl);
xedif = xdis*Math.sin(-xrot+xange);
}
lines[point] = (float) (xrow - xldif);
eles[point] = (float) (xcol - xedif);
} // end point loop
// Return in 'File' coordinates
return imageCoordToAreaCoord(linele, linele);
}
public boolean equals(Object o)
{
if (!(o instanceof RADRnav)) return false;
RADRnav that = (RADRnav) o;
return (super.equals(o) &&
that.xlat == xlat &&
that.xlon == xlon &&
that.xrow == xrow &&
that.xcol == xcol);
}
}
Ads help maintain this website.