units.h File Reference

Unit conversions for EAARL data. More...

#include "eaarlio/edb.h"
#include "eaarlio/raster.h"
#include <stdint.h>

Go to the source code of this file.

Macros
#define	EAARLIO_UNITS_SCAN_ANGLE_COUNTS_DEGREES   0.045
	Conversion factor for scan angle counts to degrees. More...
#define	EAARLIO_UNITS_TIME_FRACTION_SECONDS   1.6e-6
	Conversion factor for fractional time to seconds. More...

Functions
double	eaarlio_units_edb_time (struct eaarlio_edb_record *record)
	Returns the timestamp for an EDB record. More...
double	eaarlio_units_raster_time (struct eaarlio_raster *raster)
	Returns the timestamp for an EAARL raster. More...
double	eaarlio_units_pulse_time (struct eaarlio_raster *raster, uint16_t pulse_number)
	Returns the timestamp for a pulse in an EAARL raster. More...
double	eaarlio_units_pulse_scan_angle (struct eaarlio_pulse *pulse)
	Returns the scan angle in degrees for a pulse. More...

Detailed Description

Unit conversions for EAARL data.

This header provides constants and functions for use in converting hardware-specific units to standard units for time and angles.

Macro Definition Documentation

EAARLIO_UNITS_SCAN_ANGLE_COUNTS_DEGREES

#define EAARLIO_UNITS_SCAN_ANGLE_COUNTS_DEGREES   0.045

Conversion factor for scan angle counts to degrees.

The raw value for scan angle counts (eaarlio_pulse::scan_angle_counts) needs to be multiplied by this to convert it into degrees.

EAARLIO_UNITS_TIME_FRACTION_SECONDS

#define EAARLIO_UNITS_TIME_FRACTION_SECONDS   1.6e-6

Conversion factor for fractional time to seconds.

The raw values for fractional times (eaarlio_raster::time_fraction and eaarlio_pulse::time_offset) need to be multiplied by this to convert them to seconds.

Function Documentation

eaarlio_units_edb_time()

double eaarlio_units_edb_time

(

struct eaarlio_edb_record *

record

)

Returns the timestamp for an EDB record.

Uses the eaarlio_edb_record::time_seconds and eaarlio_edb_record::time_fraction fields to derive a timestamp in seconds of the epoch.

Parameters

[in]

record

An EDB record

Returns

The seconds-of-the-epoch timestamp for the record, or 0 if record is NULL

Examples:

example_edb_read.c.

eaarlio_units_pulse_scan_angle()

double eaarlio_units_pulse_scan_angle

(

struct eaarlio_pulse *

pulse

)

Returns the scan angle in degrees for a pulse.

Uses the eaarlio_pulse::scan_angle_counts field to derive the scan angle in degrees.

Parameters

[in]

pulse

An EAARL pulse

Returns

The scan angle in degrees, or 0 if pulse is NULL

Examples:

eaarlio_yaml.c, and example_flight_read_raster_pulse.c.

eaarlio_units_pulse_time()

double eaarlio_units_pulse_time	(	struct eaarlio_raster *	raster,
		uint16_t	pulse_number
	)

Returns the timestamp for a pulse in an EAARL raster.

Uses the eaarlio_raster::time_seconds and eaarlio_raster::time_fraction fields and the eaarlio_pulse::time_offset field from the specified pulse to derive a timestamp in seconds of the epoch.

Parameters

[in]	raster	An EAARL raster
[in]	pulse_number	The pulse number, which is a 1-based index into eaarlio_raster::pulse.

Returns

The seconds-of-the-epoch timestamp for the pulse, or 0 if raster is NULL or if the pulse cannot be retrieved

Examples:

eaarlio_yaml.c, and example_flight_read_raster_pulse.c.

eaarlio_units_raster_time()

double eaarlio_units_raster_time

(

struct eaarlio_raster *

raster

)

Returns the timestamp for an EAARL raster.

Uses the eaarlio_raster::time_seconds and eaarlio_raster::time_fraction fields to derive a timestamp in seconds of the epoch.

Parameters

[in]

raster

An EAARL raster

Returns

The seconds-of-the-epoch timestamp for the raster, or 0 if raster is NULL

Examples:

eaarlio_yaml.c, example_flight_read_raster_pulse.c, and example_flight_read_rasters.c.