mtl_geometry.h

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/*
 * Name:    mtl_geometry.h
 *
 * Purpose: Include file defining structures and function prototypes
 *      for MTL file geometric processing, including scene gridding,
 *              for angle generation.
 */
#ifndef _MTL_GEOMETRY_
#define _MTL_GEOMETRY_
 
#include <math.h>
#include <stdio.h>
#include <string.h>
#include "smeta.h"
#include "smeta_exploit.h"
#include "smeta_geometry.h"
 
#define MIN(a,b)    (a<b?a:b)
#define MAX(a,b)    (a>b?a:b)
 
typedef struct WRS2
{
  double    semimajor;      /* Earth semi-major axis in meters */
  double    semiminor;      /* Earth semi-minor axis in meters */
  double    inertialvel;        /* Earth inertial angular velocity in radians/second */
  double    orbitincl;      /* Orbital inclination in degrees */
  double    orbitrad;       /* Orbital radius in meters */
  double    path1long;      /* Longitude of path 1 descending node in degrees */
  int       numpath;        /* Number of WRS paths (233) */
  int       numrow;         /* Number of WRS rows (248) */
  int       cycle;          /* Number of days in one WRS2 cycle (16) */
  int       row0lat;        /* Equator crossing row (60) */
} WRS2;
 
typedef struct VECTOR
{
  double    x;          /* X coordinate */
  double    y;          /* Y coordinate */
  double    z;          /* Z coordinate */
} VECTOR;
 
int frame_scene(            /* Fits the nominal WRS to the MTL scene frame */
  WRS2 wrsparms,            /* I: Structure of WRS-2 parameters */
  SMETA smeta,              /* I: Input scene metadata structure */
  double *dellon,           /* O: WRS longitude offset */
  double *delrow );         /* O: Scene length in fractional WRS rows */
 
/* different variant for older LS algo */
int frame_scene_ls(         /* Fits the nominal WRS to the MTL scene frame */
  WRS2 wrsparms,            /* I: Structure of WRS-2 parameters */
  SMETA smeta,              /* I: Input scene metadata structure */
  double *dellon,           /* O: WRS longitude offset */
  double *delrow );         /* O: Scene length in fractional WRS rows */
 
 
int project_point(          /* Projects a LOS vector to the Earth */
  WRS2 wrsparms,            /* I: Structure of WRS-2 parameters */
  SMETA smeta,              /* I: Input scene metadata structure */
  double dellon,            /* I: WRS longitude offset */
  int band,             /* I: Band number (user band) */
  int sca,              /* I: SCA number (1 to nsca) */
  double frow,              /* I: Fractional WRS row coordinate */
  double ndet,              /* I: Normalized detector coordinate */
  double *l1t_line,         /* O: Projected line coordinate */
  double *l1t_samp );           /* O: Projected sample coordinate */
 
/* Slightly different variant for older LS */
int project_point_ls(           /* Projects a LOS vector to the Earth */
  WRS2 wrsparms,            /* I: Structure of WRS-2 parameters */
  SMETA smeta,              /* I: Input scene metadata structure */
  double dellon,            /* I: WRS longitude offset */
  int band,             /* I: Band number (user band) */
  double frow,              /* I: Fractional WRS row coordinate */
  double nsamp,             /* I: Sample coordinate */
  double nline,             /* I: Line coordinate */
  double *l1t_line,         /* O: Projected line coordinate */
  double *l1t_samp );           /* O: Projected sample coordinate */
 
void pathrow_to_latlon(         /* Calculates nominal WRS scene center */
  WRS2  parms,              /* I: WRS2 system parameters */
  int   path,               /* I: WRS2 path */
  double wrsrow,            /* I: WRS2 fractional row */
  double *lat,              /* O: Nominal latitude */
  double *lon );            /* O: Nominal longitude */
 
double dotprod(             /* Returns the dot product of two vectors */
  VECTOR a,             /* I: First input vector */
  VECTOR b );               /* I: Second input vector */
 
void crossprod(             /* Computes vector cross product */
  VECTOR a,             /* I: First input vector */
  VECTOR b,             /* I: Second input vector */
  VECTOR *c );              /* O: Output vector */
 
double vecnorm(             /* Returns vector magnitude */
  VECTOR a );               /* I: Input vector */
 
void unitvec(               /* Normalizes input vector */
  VECTOR a,             /* I: Input vector */
  VECTOR *b);               /* O: Normalized output vector */
 
void rotatevec(
  double mat[3][3],         /* I: 3-by-3 rotation matrix */
  VECTOR a,             /* I: Original vector */
  VECTOR *b );              /* O: Rotated vector */
 
int calc_yaw_steering_gp(       /* Returns 0 for success and -1 for failure */
  WRS2 parms,               /* I: WRS2 system parameters */
  VECTOR pos,               /* I: Position vector */
  VECTOR vel,               /* I: Velocity vector */
  VECTOR i_los,             /* I: Instrument line-of-sight unit vector */
  double roll,              /* I: Off-nadir roll angle (in degrees) */
  double *gp_lat,           /* O: Ground point geodetic latitude (in degrees) */
  double *gp_lon);          /* O: Ground point geodetic longitude (in degrees) */
 
/* variant of calc_yaw_steering_gp for other LS */
int calc_yaw_steering_gp_ls(        /* Returns 0 for success and -1 for failure */
  WRS2 parms,               /* I: WRS2 system parameters */
  VECTOR pos,               /* I: Position vector */
  VECTOR vel,               /* I: Velocity vector */
  VECTOR i_los,             /* I: Instrument line-of-sight unit vector */
  double roll,              /* I: Off-nadir roll angle (in degrees) */
  double *gp_lat,           /* O: Ground point geodetic latitude (in degrees) */
  double *gp_lon);          /* O: Ground point geodetic longitude (in degrees) */
 
int calc_los(
  SMETA_BAND band_smeta,        /* I: Metadata band structure */
  int sca,              /* I: SCA number */
  double ndet,              /* I: Normalized detector coordinate */
  VECTOR *los );            /* O: Line of sight unit vector */
 
/* Slightly different variant for older LS */
int calc_los_ls(
  SMETA_BAND_LS band_smeta,     /* I: Metadata band structure */
  double frow,                          /* I: Fractional row */
  double npix,              /* I: Sample number */
  double ndet,              /* I: Line number */
  VECTOR *los );            /* O: Line of sight unit vector */
 
void pathrow_to_posvel(
  WRS2  parms,              /* I: WRS2 system parameters */
  int   path,               /* I: WRS2 path */
  double dellon,                        /* I: Path longitude adjustment (in degrees) */
  double wrsrow,            /* I: WRS2 fractional row */
  VECTOR *pos,              /* O: Nominal position vector */
  VECTOR *vel );            /* O: Nominal velocity vector */
 
int get_ecfsun( 
  WRS2 wrsparms,            /* I: Structure of WRS-2 parameters */
  SMETA smeta,              /* I: Input scene metadata structure */
  double dellon,            /* I: WRS longitude offset */
  VECTOR *ecfsun );         /* O: Sun vector in ECEF coordinates */
 
/* Slightly different variant for older LS */
int get_ecfsun_ls(
  WRS2 wrsparms,            /* I: Structure of WRS-2 parameters */
  SMETA smeta,              /* I: Input scene metadata structure */
  double dellon,            /* I: WRS longitude offset */
  VECTOR *ecfsun );         /* O: Sun vector in ECEF coordinates */
#endif