#include <etx.h> #include <terrno.h> int etxll(xfm, line, samp, lat, lon) ETXFORM xfm; double line, samp; double *lat, *lon; int lletx(xfm, lat, lon, line, samp) ETXFORM xfm; double lat, lon; double *line, *samp; int projll(xfm, ety, etx, lat, lon) ETXFORM xfm; double ety, etx; double *lat, *lon; int llproj (xfm, lat, lon, ety, etx) ETXFORM xfm; double lat, lon; double *ety, *etx; int sensorll(xfm, line, samp, lat, lon) ETXFORM xfm; double line, samp; double *lat, *lon; int llsensor(xfm, lat, lon, line, samp) ETXFORM xfm; double lat, lon; double *line, *samp;
etxll and lletx convert between dataset (line,sample) coordinates and earth (lat,lon) coordinates.
projll and llproj convert between map projection (ety,etx) coordinates and earth (lat,lon) coordinates.
sensorll and llsensor convert between sensor (line,sample) coordinates and earth (lat,lon) coordinates.
Warning: Due to Fortran heritage, all dataset and sensor (line,sample) coordinates input to or output from these functions are assumed to be 1-relative.
Map projection coordinates are in kilometers, with (0,0) at the center of the map. Latitudes and longitudes are in degrees north and east, respectively.
etxll converts dataset coordinates into either map projection or sensor coordinates and then calls projll or sensorll. Similarly, lletx calls llproj or llsensor and converts from either map projection or sensor coordinates back to dataset coordinates.
All of these functions return 0 if successful. Otherwise, they return -1, and set terrno to the appropriate error code.
Earth transform affine mapping is singular.
Unknown projection passed by way of ETXFORM xfm.
Iterative conversion algorithm failed to converge.
Bad look angles produced from sensor geometry.
Sensor is looking into outer space, not at the earth.
include/etx.h, include/terrno.h, lib/libetx.a
etcoords, etmisc, etnames, etnav, etready etx
Last Update: $Date: 1999/05/10 20:56:39 $