MtkCreateLatLon.c

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/*===========================================================================
=                                                                           =
=                              MtkCreateLatLon                              =
=                                                                           =
=============================================================================

                         Jet Propulsion Laboratory
                                   MISR
                               MISR Toolkit

            Copyright 2005, California Institute of Technology.
                           ALL RIGHTS RESERVED.
                 U.S. Government Sponsorship acknowledged.

============================================================================*/

#include "MisrReadData.h"
#include "MisrProjParam.h"
#include "MisrMapQuery.h"
#include "MisrCoordQuery.h"
#include "MisrUtil.h"
#include "MisrError.h"

MTKt_status MtkCreateLatLon(
  MTKt_MapInfo mapinfo,     
  MTKt_DataBuffer *latbuf,  
  MTKt_DataBuffer *lonbuf    )
{
  MTKt_status status;       /* Return status */
  MTKt_status status_code;  /* Return status code for error macros */
  MTKt_DataBuffer lat = MTKT_DATABUFFER_INIT;
                                /* Latitude data buffer structure */
  MTKt_DataBuffer lon = MTKT_DATABUFFER_INIT;
                                /* Longitude data buffer structure */
  float line;           /* Data plane line index */
  float sample;         /* Data plane sample index */
  double somx;          /* SOM X */
  double somy;          /* SOM Y */
  int b;                        /* Block index */
  int l;                        /* Block line index */
  int s;                        /* Block sample index */
  int lp;                       /* Data plane integer line index */
  int sp;                       /* Data plane integer sample index */

  /* --------------------------------------------------- */
  /* Allocate buffers of the latitude and longitude data */
  /* --------------------------------------------------- */

  status = MtkDataBufferAllocate(mapinfo.nline, mapinfo.nsample,
                 MTKe_double, &lat);
  MTK_ERR_COND_JUMP(status);
  status = MtkDataBufferAllocate(mapinfo.nline, mapinfo.nsample,
                 MTKe_double, &lon);
  MTK_ERR_COND_JUMP(status);

  /* ------------------------------ */
  /* Fill with a default fill value */
  /* ------------------------------ */

  for (l = 0; l < mapinfo.nline; l++) {
    for (s = 0; s < mapinfo.nsample; s++) {
      lat.data.d[l][s] = -200.0;
      lon.data.d[l][s] = -200.0;
    }
  }

  /* --------------------------------------------------------------- */
  /* Compute the lat/lon for each block/line/sample in the swath     */
  /* that intersect with the data plane defined my mapinfo           */
  /* --------------------------------------------------------------- */

  for (b = mapinfo.start_block; b <= mapinfo.end_block; b++) {
    for (l = 0; l < mapinfo.pp.nline; l++) {
      for (s = 0; s < mapinfo.pp.nsample; s++) {
    MtkBlsToSomXY(mapinfo.path, mapinfo.resolution, b, (float)l, (float)s,
              &somx, &somy);
    MtkSomXYToLS(mapinfo, somx, somy, &line, &sample);
    lp = (int)line;
    sp = (int)sample;
    if (lp >= 0 && lp < mapinfo.nline &&
        sp >= 0 && sp < mapinfo.nsample) {
      MtkSomXYToLatLon(mapinfo.path, somx, somy, 
               &(lat.data.d[lp][sp]), &(lon.data.d[lp][sp]));
    }
      }
    }
  }

  *latbuf = lat;
  *lonbuf = lon;

  return MTK_SUCCESS;
 ERROR_HANDLE:
  MtkDataBufferFree(&lat);
  MtkDataBufferFree(&lon);
  return status_code;
}