get_nc_height.c File Reference

#include "l12_proto.h"
#include "nc_gridutils.h"

Include dependency graph for get_nc_height.c:

Go to the source code of this file.

Classes
struct	tile_struct

Macros
#define	TILE_ROWS   120
#define	MAXSENZEN   75
#define	BORDER   0.30
#define	REMM   6371000.000

Functions
void	print_area (grid_area_t area)
void	print_tile (tile_struct tile)
void	define_tile_geometry ()
int	initialize_deminfo ()
void	free_deminfo ()
void	unload_tile (int itile)
void	load_tile_cache (int itile)
int	load_tile (float lat, float lon)
int	tile_findex (tile_struct tile, float lat, float lon, double *findex)
int	tile_index (tile_struct tile, float lat, float lon, size_t *index)
int	get_tilevalue (tile_struct tile, float lat, float lon, double *value)
int	interp_tilevalue (tile_struct tile, float lat, float lon, double *result)
int	get_nc_height (float *xlon, float *xlat, float *senz, float *sena, float *height)
int	lookup_nc_height (float *xlon, float *xlat, float *height)
int	interp_nc_height (float *xlon, float *xlat, float *height)

Detailed Description

Reads DEM from NetCDF4 file, and performs terrain correction.

Author

Gwyn Fireman

Ocean Ecology Laboratory, NASA Goddard Space Flight Center

Definition in file get_nc_height.c.

Macro Definition Documentation

BORDER

#define BORDER   0.30

Degrees latitude around each tile; calculated from MAXSENZEN.

Definition at line 15 of file get_nc_height.c.

MAXSENZEN

#define MAXSENZEN   75

Maximum sensor zenith angle; avoid limb.

Definition at line 13 of file get_nc_height.c.

REMM

#define REMM   6371000.000

Earth mean radius (m).

Definition at line 17 of file get_nc_height.c.

TILE_ROWS

#define TILE_ROWS   120

Number of tile (latitude) rows, adjustable for performance.

Definition at line 11 of file get_nc_height.c.

Function Documentation

define_tile_geometry()

void define_tile_geometry

(

)

Divide the globe into approximately equal-area chunks.

Definition at line 97 of file get_nc_height.c.

free_deminfo()

void free_deminfo

(

)

Definition at line 227 of file get_nc_height.c.

get_nc_height()

int get_nc_height	(	float *	xlon,
		float *	xlat,
		float *	senz,
		float *	sena,
		float *	height
	)

Perform terrain correction; return DEM value

Parameters

[in,out]	xlon,xlat
[in,out]	senz
[in]	sena
[out]	height

Returns

Definition at line 574 of file get_nc_height.c.

get_tilevalue()

int get_tilevalue	(	tile_struct	tile,
		float	lat,
		float	lon,
		double *	value
	)

Parameters

[in]	tile
[in]	lat,lon
[out]	value

Returns

Definition at line 485 of file get_nc_height.c.

initialize_deminfo()

int initialize_deminfo

(

)

Parameters

[in]

demfile

(via input struct)

Returns

Definition at line 190 of file get_nc_height.c.

interp_nc_height()

int interp_nc_height	(	float *	xlon,
		float *	xlat,
		float *	height
	)

Return DEM value obtained by interpolating between four nearest points.

Parameters

[in]	xlon,xlat
[out]	height

Returns

Definition at line 735 of file get_nc_height.c.

interp_tilevalue()

int interp_tilevalue	(	tile_struct	tile,
		float	lat,
		float	lon,
		double *	result
	)

Parameters

[in]	tile
[in]	lat,lon
[out]	result

Returns

Definition at line 503 of file get_nc_height.c.

load_tile()

int load_tile	(	float	lat,
		float	lon
	)

Parameters

[in]	dem_tile_t
[in]	lat
[in]	lon

Returns

Definition at line 285 of file get_nc_height.c.

load_tile_cache()

void load_tile_cache

(

int

itile

)

Definition at line 261 of file get_nc_height.c.

lookup_nc_height()

int lookup_nc_height	(	float *	xlon,
		float *	xlat,
		float *	height
	)

Return DEM value nearest to specified coordinates.

Parameters

[in]	xlon,xlat
[out]	height

Returns

Definition at line 705 of file get_nc_height.c.

print_area()

void print_area

(

grid_area_t

area

)

Print info for a rectangular area.

Parameters

[in]

area

Definition at line 63 of file get_nc_height.c.

print_tile()

void print_tile

(

tile_struct

tile

)

Print info for a single tile.

Parameters

[in]

tile

Definition at line 76 of file get_nc_height.c.

tile_findex()

int tile_findex	(	tile_struct	tile,
		float	lat,
		float	lon,
		double *	findex
	)

Floating-point index of lat, lon within current tile.

Parameters

[in]	tile
[in]	lat,lon
[out]	findex

Returns

Definition at line 408 of file get_nc_height.c.

tile_index()

int tile_index	(	tile_struct	tile,
		float	lat,
		float	lon,
		size_t *	index
	)

Integer index of lat, lon within current tile.

Parameters

[in]	tile
[in]	lat,lon
[out]	index

Returns

Definition at line 460 of file get_nc_height.c.

unload_tile()

void unload_tile

(

int

itile

)

Definition at line 252 of file get_nc_height.c.

Variable Documentation

ncols

size_t ncols[TILE_ROWS]

Definition at line 54 of file get_nc_height.c.

ntiles

size_t ntiles

Definition at line 53 of file get_nc_height.c.

start_tile

size_t start_tile[TILE_ROWS]

Definition at line 55 of file get_nc_height.c.

tiles

tile_struct* tiles

Definition at line 56 of file get_nc_height.c.