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/**
 * @file airspeed.h
 * Airspeed estimation declarations
 *
 * @author Lorenz Meier <lorenz@px4.io>
 *
 */

#ifndef AIRSPEED_H_
#define AIRSPEED_H_

#include "math.h"
#include "conversions.h"

__BEGIN_DECLS

enum AIRSPEED_SENSOR_MODEL {
	AIRSPEED_SENSOR_MODEL_MEMBRANE = 0,
	AIRSPEED_SENSOR_MODEL_SDP3X,
};

enum AIRSPEED_COMPENSATION_MODEL {
	AIRSPEED_COMPENSATION_MODEL_PITOT = 0,
	AIRSPEED_COMPENSATION_MODEL_NO_PITOT = 1,
	AIRSPEED_COMPENSATION_TUBE_PRESSURE_LOSS = 2
};

/**
 * Calculate indicated airspeed.
 *
 * Note that the indicated airspeed is not the true airspeed because it
 * lacks the air density compensation. Use the calc_true_airspeed functions to get
 * the true airspeed.
 *
 * @param total_pressure pressure inside the pitot/prandtl tube
 * @param static_pressure pressure at the side of the tube/airplane
 * @return indicated airspeed in m/s
 */
__EXPORT float calc_indicated_airspeed_corrected(enum AIRSPEED_COMPENSATION_MODEL pmodel,
		enum AIRSPEED_SENSOR_MODEL smodel,
		float tube_len, float tube_dia_mm, float differential_pressure, float pressure_ambient, float temperature_celsius);

/**
 * Calculate indicated airspeed.
 *
 * Note that the indicated airspeed is not the true airspeed because it
 * lacks the air density compensation. Use the calc_true_airspeed functions to get
 * the true airspeed.
 *
 * @param total_pressure pressure inside the pitot/prandtl tube
 * @param static_pressure pressure at the side of the tube/airplane
 * @return indicated airspeed in m/s
 */
__EXPORT float calc_indicated_airspeed(float differential_pressure);

/**
 * Calculate true airspeed from indicated airspeed.
 *
 * Note that the true airspeed is NOT the groundspeed, because of the effects of wind
 *
 * @param speed_indicated current indicated airspeed
 * @param pressure_ambient pressure at the side of the tube/airplane
 * @param temperature_celsius air temperature in degrees celcius
 * @return true airspeed in m/s
 */
__EXPORT float calc_true_airspeed_from_indicated(float speed_indicated, float pressure_ambient,
		float temperature_celsius);

/**
 * Directly calculate true airspeed
 *
 * Note that the true airspeed is NOT the groundspeed, because of the effects of wind
 *
 * @param total_pressure pressure inside the pitot/prandtl tube
 * @param static_pressure pressure at the side of the tube/airplane
 * @param temperature_celsius air temperature in degrees celcius
 * @return true airspeed in m/s
 */
__EXPORT float calc_true_airspeed(float total_pressure, float static_pressure, float temperature_celsius);

/**
* Calculates air density.
*
* @param static_pressure ambient pressure in millibar
* @param temperature_celcius air / ambient temperature in celcius
*/
__EXPORT float get_air_density(float static_pressure, float temperature_celsius);

__END_DECLS

#endif
