/****************************************************************************
 *
 *   Copyright (c) 2015-2016 Estimation and Control Library (ECL). All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name ECL nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/**
 * @file ekf2_params.c
 * Parameter definition for ekf2.
 *
 * @author Roman Bast <bapstroman@gmail.com>
 *
 */

/**
 * Minimum time of arrival delta between non-IMU observations before data is downsampled.
 *
 * Baro and Magnetometer data will be averaged before downsampling, other data will be point sampled resulting in loss of information.
 *
 * @group EKF2
 * @min 10
 * @max 50
 * @reboot_required true
 * @unit ms
 */
PARAM_DEFINE_INT32(EKF2_MIN_OBS_DT, 20);

/**
 * Magnetometer measurement delay relative to IMU measurements
 *
 * @group EKF2
 * @min 0
 * @max 300
 * @unit ms
 * @reboot_required true
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_MAG_DELAY, 0);

/**
 * Barometer measurement delay relative to IMU measurements
 *
 * @group EKF2
 * @min 0
 * @max 300
 * @unit ms
 * @reboot_required true
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_BARO_DELAY, 0);

/**
 * GPS measurement delay relative to IMU measurements
 *
 * @group EKF2
 * @min 0
 * @max 300
 * @unit ms
 * @reboot_required true
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_GPS_DELAY, 110);

/**
 * Optical flow measurement delay relative to IMU measurements
 *
 * Assumes measurement is timestamped at trailing edge of integration period
 *
 * @group EKF2
 * @min 0
 * @max 300
 * @unit ms
 * @reboot_required true
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_OF_DELAY, 20);

/**
 * Range finder measurement delay relative to IMU measurements
 *
 * @group EKF2
 * @min 0
 * @max 300
 * @unit ms
 * @reboot_required true
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_DELAY, 5);

/**
 * Airspeed measurement delay relative to IMU measurements
 *
 * @group EKF2
 * @min 0
 * @max 300
 * @unit ms
 * @reboot_required true
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_ASP_DELAY, 100);

/**
 * Vision Position Estimator delay relative to IMU measurements
 *
 * @group EKF2
 * @min 0
 * @max 300
 * @unit ms
 * @reboot_required true
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_EV_DELAY, 175);

/**
 * Auxillary Velocity Estimate (e.g from a landing target) delay relative to IMU measurements
 *
 * @group EKF2
 * @min 0
 * @max 300
 * @unit ms
 * @reboot_required true
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_AVEL_DELAY, 5);

/**
 * Integer bitmask controlling GPS checks.
 *
 * Set bits to 1 to enable checks. Checks enabled by the following bit positions
 * 0 : Minimum required sat count set by EKF2_REQ_NSATS
 * 1 : Maximum allowed PDOP set by EKF2_REQ_PDOP
 * 2 : Maximum allowed horizontal position error set by EKF2_REQ_EPH
 * 3 : Maximum allowed vertical position error set by EKF2_REQ_EPV
 * 4 : Maximum allowed speed error set by EKF2_REQ_SACC
 * 5 : Maximum allowed horizontal position rate set by EKF2_REQ_HDRIFT. This check will only run when the vehicle is on ground and stationary. Detecton of the stationary condition is controlled by the EKF2_MOVE_TEST parameter.
 * 6 : Maximum allowed vertical position rate set by EKF2_REQ_VDRIFT. This check will only run when the vehicle is on ground and stationary. Detecton of the stationary condition is controlled by the EKF2_MOVE_TEST parameter.
 * 7 : Maximum allowed horizontal speed set by EKF2_REQ_HDRIFT. This check will only run when the vehicle is on ground and stationary. Detecton of the stationary condition is controlled by the EKF2_MOVE_TEST parameter.
 * 8 : Maximum allowed vertical velocity discrepancy set by EKF2_REQ_VDRIFT
 *
 * @group EKF2
 * @min 0
 * @max 511
 * @bit 0 Min sat count (EKF2_REQ_NSATS)
 * @bit 1 Max PDOP (EKF2_REQ_PDOP)
 * @bit 2 Max horizontal position error (EKF2_REQ_EPH)
 * @bit 3 Max vertical position error (EKF2_REQ_EPV)
 * @bit 4 Max speed error (EKF2_REQ_SACC)
 * @bit 5 Max horizontal position rate (EKF2_REQ_HDRIFT)
 * @bit 6 Max vertical position rate (EKF2_REQ_VDRIFT)
 * @bit 7 Max horizontal speed (EKF2_REQ_HDRIFT)
 * @bit 8 Max vertical velocity discrepancy (EKF2_REQ_VDRIFT)
 */
PARAM_DEFINE_INT32(EKF2_GPS_CHECK, 245);

/**
 * Required EPH to use GPS.
 *
 * @group EKF2
 * @min 2
 * @max 100
 * @unit m
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_REQ_EPH, 3.0f);

/**
 * Required EPV to use GPS.
 *
 * @group EKF2
 * @min 2
 * @max 100
 * @unit m
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_REQ_EPV, 5.0f);

/**
 * Required speed accuracy to use GPS.
 *
 * @group EKF2
 * @min 0.5
 * @max 5.0
 * @unit m/s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_REQ_SACC, 0.5f);

/**
 * Required satellite count to use GPS.
 *
 * @group EKF2
 * @min 4
 * @max 12
 */
PARAM_DEFINE_INT32(EKF2_REQ_NSATS, 6);

/**
 * Maximum PDOP to use GPS.
 *
 * @group EKF2
 * @min 1.5
 * @max 5.0
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_REQ_PDOP, 2.5f);

/**
 * Maximum horizontal drift speed to use GPS.
 *
 * @group EKF2
 * @min 0.1
 * @max 1.0
 * @unit m/s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_REQ_HDRIFT, 0.1f);

/**
 * Maximum vertical drift speed to use GPS.
 *
 * @group EKF2
 * @min 0.1
 * @max 1.5
 * @decimal 2
 * @unit m/s
 */
PARAM_DEFINE_FLOAT(EKF2_REQ_VDRIFT, 0.2f);

/**
 * Rate gyro noise for covariance prediction.
 *
 * @group EKF2
 * @min 0.0001
 * @max 0.1
 * @unit rad/s
 * @decimal 4
 */
PARAM_DEFINE_FLOAT(EKF2_GYR_NOISE, 1.5e-2f);

/**
 * Accelerometer noise for covariance prediction.
 *
 * @group EKF2
 * @min 0.01
 * @max 1.0
 * @unit m/s^2
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_ACC_NOISE, 3.5e-1f);

/**
 * Process noise for IMU rate gyro bias prediction.
 *
 * @group EKF2
 * @min 0.0
 * @max 0.01
 * @unit rad/s^2
 * @decimal 6
 */
PARAM_DEFINE_FLOAT(EKF2_GYR_B_NOISE, 1.0e-3f);

/**
 * Process noise for IMU accelerometer bias prediction.
 *
 * @group EKF2
 * @min 0.0
 * @max 0.01
 * @unit m/s^3
 * @decimal 6
 */
PARAM_DEFINE_FLOAT(EKF2_ACC_B_NOISE, 3.0e-3f);

/**
 * Process noise for body magnetic field prediction.
 *
 * @group EKF2
 * @min 0.0
 * @max 0.1
 * @unit gauss/s
 * @decimal 6
 */
PARAM_DEFINE_FLOAT(EKF2_MAG_B_NOISE, 1.0e-4f);

/**
 * Process noise for earth magnetic field prediction.
 *
 * @group EKF2
 * @min 0.0
 * @max 0.1
 * @unit gauss/s
 * @decimal 6
 */
PARAM_DEFINE_FLOAT(EKF2_MAG_E_NOISE, 1.0e-3f);

/**
 * Process noise for wind velocity prediction.
 *
 * @group EKF2
 * @min 0.0
 * @max 1.0
 * @unit m/s^2
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_WIND_NOISE, 1.0e-1f);

/**
 * Measurement noise for gps horizontal velocity.
 *
 * @group EKF2
 * @min 0.01
 * @max 5.0
 * @unit m/s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_GPS_V_NOISE, 0.3f);

/**
 * Measurement noise for gps position.
 *
 * @group EKF2
 * @min 0.01
 * @max 10.0
 * @unit m
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_GPS_P_NOISE, 0.5f);

/**
 * Measurement noise for non-aiding position hold.
 *
 * @group EKF2
 * @min 0.5
 * @max 50.0
 * @unit m
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_NOAID_NOISE, 10.0f);

/**
 * Measurement noise for barometric altitude.
 *
 * @group EKF2
 * @min 0.01
 * @max 15.0
 * @unit m
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_BARO_NOISE, 3.5f);

/**
 * Measurement noise for magnetic heading fusion.
 *
 * @group EKF2
 * @min 0.01
 * @max 1.0
 * @unit rad
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_HEAD_NOISE, 0.3f);

/**
 * Measurement noise for magnetometer 3-axis fusion.
 *
 * @group EKF2
 * @min 0.001
 * @max 1.0
 * @unit gauss
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_MAG_NOISE, 5.0e-2f);

/**
 * Measurement noise for airspeed fusion.
 *
 * @group EKF2
 * @min 0.5
 * @max 5.0
 * @unit m/s
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_EAS_NOISE, 1.4f);

/**
 * Gate size for synthetic sideslip fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_BETA_GATE, 5.0f);

/**
 * Noise for synthetic sideslip fusion.
 *
 * @group EKF2
 * @min 0.1
 * @max 1.0
 * @unit m/s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_BETA_NOISE, 0.3f);

/**
 * Gate size for magnetic heading fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_HDG_GATE, 2.6f);

/**
 * Gate size for magnetometer XYZ component fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_MAG_GATE, 3.0f);

/**
 * Integer bitmask controlling handling of magnetic declination.
 *
 * Set bits in the following positions to enable functions.
 * 0 : Set to true to use the declination from the geo_lookup library when the GPS position becomes available, set to false to always use the EKF2_MAG_DECL value.
 * 1 : Set to true to save the EKF2_MAG_DECL parameter to the value returned by the EKF when the vehicle disarms.
 * 2 : Set to true to always use the declination as an observation when 3-axis magnetometer fusion is being used.
 *
 * @group EKF2
 * @min 0
 * @max 7
 * @bit 0 use geo_lookup declination
 * @bit 1 save EKF2_MAG_DECL on disarm
 * @bit 2 use declination as an observation
 * @reboot_required true
 */
PARAM_DEFINE_INT32(EKF2_DECL_TYPE, 7);

/**
 * Type of magnetometer fusion
 *
 * Integer controlling the type of magnetometer fusion used - magnetic heading or 3-component vector. The fuson of magnetomer data as a three component vector enables vehicle body fixed hard iron errors to be learned, but requires a stable earth field.
 * If set to 'Automatic' magnetic heading fusion is used when on-ground and 3-axis magnetic field fusion in-flight with fallback to magnetic heading fusion if there is insufficient motion to make yaw or magnetic field states observable.
 * If set to 'Magnetic heading' magnetic heading fusion is used at all times
 * If set to '3-axis' 3-axis field fusion is used at all times.
 * If set to 'VTOL custom' the behaviour is the same as 'Automatic', but if fusing airspeed, magnetometer fusion is only allowed to modify the magnetic field states. This can be used by VTOL platforms with large magnetic field disturbances to prevent incorrect bias states being learned during forward flight operation which can adversely affect estimation accuracy after transition to hovering flight.
 * If set to 'MC custom' the behaviour is the same as 'Automatic, but if there are no earth frame position or velocity observations being used, the magnetometer will not be used. This enables vehicles to operate with no GPS in environments where the magnetic field cannot be used to provide a heading reference. Prior to flight, the yaw angle is assumed to be constant if movement tests controlled by the EKF2_MOVE_TEST parameter indicate that the vehicle is static. This allows the vehicle to be placed on the ground to learn the yaw gyro bias prior to flight.
 * If set to 'None' the magnetometer will not be used under any circumstance. If no external source of yaw is available, it is possible to use post-takeoff horizontal movement combined with GPS velocity measurements to align the yaw angle with the timer required (depending on the amount of movement and GPS data quality). Other external sources of yaw may be used if selected via the EKF2_AID_MASK parameter.
 * @group EKF2
 * @value 0 Automatic
 * @value 1 Magnetic heading
 * @value 2 3-axis
 * @value 3 VTOL custom
 * @value 4 MC custom
 * @value 5 None
 * @reboot_required true
 */
PARAM_DEFINE_INT32(EKF2_MAG_TYPE, 0);

/**
 * Horizontal acceleration threshold used by automatic selection of magnetometer fusion method.
 *
 * This parameter is used when the magnetometer fusion method is set automatically (EKF2_MAG_TYPE = 0). If the filtered horizontal acceleration is greater than this parameter value, then the EKF will use 3-axis magnetomer fusion.
 *
 * @group EKF2
 * @min 0.0
 * @max 5.0
 * @unit m/s^2
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_MAG_ACCLIM, 0.5f);

/**
 * Yaw rate threshold used by automatic selection of magnetometer fusion method.
 *
 * This parameter is used when the magnetometer fusion method is set automatically (EKF2_MAG_TYPE = 0). If the filtered yaw rate is greater than this parameter value, then the EKF will use 3-axis magnetomer fusion.
 *
 * @group EKF2
 * @min 0.0
 * @max 1.0
 * @unit rad/s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_MAG_YAWLIM, 0.25f);

/**
 * Gate size for barometric and GPS height fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_BARO_GATE, 5.0f);

/**
 * Baro deadzone range for height fusion
 *
 * Sets the value of deadzone applied to negative baro innovations.
 * Deadzone is enabled when EKF2_GND_EFF_DZ > 0.
 *
 * @group EKF2
 * @min 0.0
 * @max 10.0
 * @unit m
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_GND_EFF_DZ, 0.0f);

/**
 * Height above ground level for ground effect zone
 *
 * Sets the maximum distance to the ground level where negative baro innovations are expected.
 *
 * @group EKF2
 * @min 0.0
 * @max 5.0
 * @unit m
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_GND_MAX_HGT, 0.5f);

/**
 * Gate size for GPS horizontal position fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_GPS_P_GATE, 5.0f);

/**
 * Gate size for GPS velocity fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_GPS_V_GATE, 5.0f);

/**
 * Gate size for TAS fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_TAS_GATE, 3.0f);

/**
 * Integer bitmask controlling data fusion and aiding methods.
 *
 * Set bits in the following positions to enable:
 * 0 : Set to true to use GPS data if available
 * 1 : Set to true to use optical flow data if available
 * 2 : Set to true to inhibit IMU delta velocity bias estimation
 * 3 : Set to true to enable vision position fusion
 * 4 : Set to true to enable vision yaw fusion. Cannot be used if bit position 7 is true.
 * 5 : Set to true to enable multi-rotor drag specific force fusion
 * 6 : set to true if the EV observations are in a non NED reference frame and need to be rotated before being used
 * 7 : Set to true to enable GPS yaw fusion. Cannot be used if bit position 4 is true.
 *
 * @group EKF2
 * @min 0
 * @max 511
 * @bit 0 use GPS
 * @bit 1 use optical flow
 * @bit 2 inhibit IMU bias estimation
 * @bit 3 vision position fusion
 * @bit 4 vision yaw fusion
 * @bit 5 multi-rotor drag fusion
 * @bit 6 rotate external vision
 * @bit 7 GPS yaw fusion
 * @bit 8 vision velocity fusion
 * @reboot_required true
 */
PARAM_DEFINE_INT32(EKF2_AID_MASK, 1);

/**
 * Determines the primary source of height data used by the EKF.
 *
 * The range sensor option should only be used when for operation over a flat surface as the local NED origin will move up and down with ground level.
 *
 * @group EKF2
 * @value 0 Barometric pressure
 * @value 1 GPS
 * @value 2 Range sensor
 * @value 3 Vision
 * @reboot_required true
 */
PARAM_DEFINE_INT32(EKF2_HGT_MODE, 0);

/**
 * Integer bitmask controlling fusion sources of the terrain estimator
 *
 * Set bits in the following positions to enable:
 * 0 : Set to true to use range finder data if available
 * 1 : Set to true to use optical flow data if available
 *
 * @group EKF2
 * @min 0
 * @max 3
 * @bit 0 use range finder
 * @bit 1 use optical flow
 */
PARAM_DEFINE_INT32(EKF2_TERR_MASK, 3);

/**
 * Maximum lapsed time from last fusion of measurements that constrain velocity drift before the EKF will report the horizontal nav solution as invalid.
 *
 * @group EKF2
 * @group EKF2
 * @min 500000
 * @max 10000000
 * @unit us
 */
PARAM_DEFINE_INT32(EKF2_NOAID_TOUT, 5000000);

/**
 * Measurement noise for range finder fusion
 *
 * @group EKF2
 * @min 0.01
 * @unit m
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_NOISE, 0.1f);

/**
 * Range finder range dependant noise scaler.
 *
 * Specifies the increase in range finder noise with range.
 *
 * @group EKF2
 * @min 0.0
 * @max 0.2
 * @unit m/m
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_SFE, 0.05f);

/**
 * Gate size for range finder fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_GATE, 5.0f);

/**
 * Expected range finder reading when on ground.
 *
 * If the vehicle is on ground, is not moving as determined by the motion test controlled by EKF2_MOVE_TEST and the range finder is returning invalid or no data, then an assumed range value of EKF2_MIN_RNG will be used by the terrain estimator so that a terrain height estimate is avilable at the start of flight in situations where the range finder may be inside its minimum measurements distance when on ground.
 *
 * @group EKF2
 * @min 0.01
 * @unit m
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_MIN_RNG, 0.1f);

/**
 * Whether to set the external vision observation noise from the parameter or from vision message
 *
 * If set to true the observation noise is set from the parameters directly, if set to false the measurement noise is taken from the vision message and the parameter are used as a lower bound.
 *
 * @boolean
 * @group EKF2
 */
PARAM_DEFINE_INT32(EKF2_EV_NOISE_MD, 0);

/**
 * Measurement noise for vision position observations used to lower bound or replace the uncertainty included in the message
 *
 * @group EKF2
 * @min 0.01
 * @unit m
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_EVP_NOISE, 0.1f);

/**
 * Measurement noise for vision velocity observations used to lower bound or replace the uncertainty included in the message
 *
 * @group EKF2
 * @min 0.01
 * @unit m/s
 * @decimal 2
*/
PARAM_DEFINE_FLOAT(EKF2_EVV_NOISE, 0.1f);

/**
 * Measurement noise for vision angle observations used to lower bound or replace the uncertainty included in the message
 *
 * @group EKF2
 * @min 0.05
 * @unit rad
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_EVA_NOISE, 0.05f);

/**
 * Measurement noise for the optical flow sensor when it's reported quality metric is at the maximum
 *
 * @group EKF2
 * @min 0.05
 * @unit rad/s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_OF_N_MIN, 0.15f);

/**
 * Measurement noise for the optical flow sensor.
 *
 * (when it's reported quality metric is at the minimum set by EKF2_OF_QMIN).
 * The following condition must be met: EKF2_OF_N_MAXN >= EKF2_OF_N_MIN
 *
 * @group EKF2
 * @min 0.05
 * @unit rad/s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_OF_N_MAX, 0.5f);

/**
 * Optical Flow data will only be used if the sensor reports a quality metric >= EKF2_OF_QMIN.
 *
 * @group EKF2
 * @min 0
 * @max 255
 */
PARAM_DEFINE_INT32(EKF2_OF_QMIN, 1);

/**
 * Gate size for optical flow fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_OF_GATE, 3.0f);

/**
 * Terrain altitude process noise - accounts for instability in vehicle height estimate
 *
 * @group EKF2
 * @min 0.5
 * @unit m/s
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_TERR_NOISE, 5.0f);

/**
 * Magnitude of terrain gradient
 *
 * @group EKF2
 * @min 0.0
 * @unit m/m
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_TERR_GRAD, 0.5f);

/**
 * X position of IMU in body frame (forward axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_IMU_POS_X, 0.0f);

/**
 * Y position of IMU in body frame (right axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_IMU_POS_Y, 0.0f);

/**
 * Z position of IMU in body frame (down axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_IMU_POS_Z, 0.0f);

/**
 * X position of GPS antenna in body frame (forward axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_GPS_POS_X, 0.0f);

/**
 * Y position of GPS antenna in body frame (right axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_GPS_POS_Y, 0.0f);

/**
 * Z position of GPS antenna in body frame (down axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_GPS_POS_Z, 0.0f);

/**
 * X position of range finder origin in body frame (forward axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_POS_X, 0.0f);

/**
 * Y position of range finder origin in body frame (right axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_POS_Y, 0.0f);

/**
 * Z position of range finder origin in body frame (down axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_POS_Z, 0.0f);

/**
 * X position of optical flow focal point in body frame (forward axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_OF_POS_X, 0.0f);

/**
 * Y position of optical flow focal point in body frame (right axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_OF_POS_Y, 0.0f);

/**
 * Z position of optical flow focal point in body frame (down axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_OF_POS_Z, 0.0f);

/**
* X position of VI sensor focal point in body frame (forward axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_EV_POS_X, 0.0f);

/**
 * Y position of VI sensor focal point in body frame (right axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_EV_POS_Y, 0.0f);

/**
 * Z position of VI sensor focal point in body frame (down axis with origin relative to vehicle centre of gravity)
 *
 * @group EKF2
 * @unit m
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_EV_POS_Z, 0.0f);

/**
* Airspeed fusion threshold.
*
* A value of zero will deactivate airspeed fusion. Any other positive
* value will determine the minimum airspeed which will still be fused. Set to about 90% of the vehicles stall speed.
* Both airspeed fusion and sideslip fusion must be active for the EKF to continue navigating after loss of GPS.
* Use EKF2_FUSE_BETA to activate sideslip fusion.
*
* @group EKF2
* @min 0.0
* @unit m/s
* @decimal 1
*/
PARAM_DEFINE_FLOAT(EKF2_ARSP_THR, 0.0f);

/**
* Boolean determining if synthetic sideslip measurements should fused.
*
* A value of 1 indicates that fusion is active
* Both  sideslip fusion and airspeed fusion must be active for the EKF to continue navigating after loss of GPS.
* Use EKF2_ARSP_THR to activate airspeed fusion.
*
* @group EKF2
* @boolean
*/
PARAM_DEFINE_INT32(EKF2_FUSE_BETA, 0);

/**

 * Time constant of the velocity output prediction and smoothing filter
 *
 * @group EKF2
 * @max 1.0
 * @unit s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_TAU_VEL, 0.25f);

/**
 * Time constant of the position output prediction and smoothing filter. Controls how tightly the output track the EKF states.
 *
 * @group EKF2
 * @min 0.1
 * @max 1.0
 * @unit s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_TAU_POS, 0.25f);

/**
 * 1-sigma IMU gyro switch-on bias
 *
 * @group EKF2
 * @min 0.0
 * @max 0.2
 * @unit rad/s
 * @reboot_required true
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_GBIAS_INIT, 0.1f);

/**
 * 1-sigma IMU accelerometer switch-on bias
 *
 * @group EKF2
 * @min 0.0
 * @max 0.5
 * @unit m/s^2
 * @reboot_required true
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_ABIAS_INIT, 0.2f);

/**
 * 1-sigma tilt angle uncertainty after gravity vector alignment
 *
 * @group EKF2
 * @min 0.0
 * @max 0.5
 * @unit rad
 * @reboot_required true
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_ANGERR_INIT, 0.1f);

/**
 * Range sensor pitch offset.
 *
 * @group EKF2
 * @min -0.75
 * @max 0.75
 * @unit rad
 * @decimal 3
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_PITCH, 0.0f);

/**
 * Range sensor aid.
 *
 * If this parameter is enabled then the estimator will make use of the range finder measurements
 * to estimate it's height even if range sensor is not the primary height source. It will only do so if conditions
 * for range measurement fusion are met. This enables the range finder to be used during low speed and low altitude
 * operation, eg takeoff and landing, where baro interference from rotor wash is excessive and can corrupt EKF state
 * estimates. It is intended to be used where a vertical takeoff and landing is performed, and horizontal flight does
 * not occur until above EKF2_RNG_A_HMAX. If vehicle motion causes repeated switching between the primary height
 * sensor and range finder, an offset in the local position origin can accumulate. Also range finder measurements
 * are less reliable and can experience unexpected errors. For these reasons, if accurate control of height
 * relative to ground is required, it is recommended to use the MPC_ALT_MODE parameter instead, unless baro errors
 * are severe enough to cause problems with landing and takeoff.
 *
 * @group EKF2
 * @value 0 Range aid disabled
 * @value 1 Range aid enabled
 */
PARAM_DEFINE_INT32(EKF2_RNG_AID, 0);

/**
 * Maximum horizontal velocity allowed for range aid mode.
 *
 * If the vehicle horizontal speed exceeds this value then the estimator will not fuse range measurements
 * to estimate it's height. This only applies when range aid mode is activated (EKF2_RNG_AID = enabled).
 *
 * @group EKF2
 * @min 0.1
 * @max 2
 * @unit m/s
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_A_VMAX, 1.0f);

/**
 * Maximum absolute altitude (height above ground level) allowed for range aid mode.
 *
 * If the vehicle absolute altitude exceeds this value then the estimator will not fuse range measurements
 * to estimate it's height. This only applies when range aid mode is activated (EKF2_RNG_AID = enabled).
 *
 * @group EKF2
 * @min 1.0
 * @max 10.0
 * @unit m
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_A_HMAX, 5.0f);

/**
 * Gate size used for innovation consistency checks for range aid fusion
 *
 * A lower value means HAGL needs to be more stable in order to use range finder for height estimation
 * in range aid mode
 *
 * @group EKF2
 * @unit SD
 * @min 0.1
 * @max 5.0
 */
PARAM_DEFINE_FLOAT(EKF2_RNG_A_IGATE, 1.0f);

/**
 * Minimum duration during which the reported range finder signal quality needs to be non-zero in order to be declared valid (s)
 *
 *
 * @group EKF2
 * @unit s
 * @min 0.1
 * @max 5
*/
PARAM_DEFINE_FLOAT(EKF2_RNG_QLTY_T, 1.0f);

/**
 * Gate size for vision velocity estimate fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 *
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
*/
PARAM_DEFINE_FLOAT(EKF2_EVV_GATE, 3.0f);

/**
 * Gate size for vision position fusion
 *
 * Sets the number of standard deviations used by the innovation consistency test.
 * @group EKF2
 * @min 1.0
 * @unit SD
 * @decimal 1
*/
PARAM_DEFINE_FLOAT(EKF2_EVP_GATE, 5.0f);

/**
 * Specific drag force observation noise variance used by the multi-rotor specific drag force model.
 *
 * Increasing this makes the multi-rotor wind estimates adjust more slowly.
 *
 * @group EKF2
 * @min 0.5
 * @max 10.0
 * @unit (m/s^2)^2
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_DRAG_NOISE, 2.5f);

/**
 * X-axis ballistic coefficient used by the multi-rotor specific drag force model.
 *
 * This should be adjusted to minimise variance of the X-axis drag specific force innovation sequence.
 *
 * @group EKF2
 * @min 1.0
 * @max 100.0
 * @unit kg/m^2
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_BCOEF_X, 25.0f);

/**
 * Y-axis ballistic coefficient used by the multi-rotor specific drag force model.
 *
 * This should be adjusted to minimise variance of the Y-axis drag specific force innovation sequence.
 *
 * @group EKF2
 * @min 1.0
 * @max 100.0
 * @unit kg/m^2
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_BCOEF_Y, 25.0f);

/**
 * Upper limit on airspeed along individual axes used to correct baro for position error effects
 *
 * @group EKF2
 * @min 5.0
 * @max 50.0
 * @unit m/s
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_ASPD_MAX, 20.0f);

/**
 * Static pressure position error coefficient for the positive X axis
 *
 * This is the ratio of static pressure error to dynamic pressure generated by a positive wind relative velocity along the X body axis.
 * If the baro height estimate rises during forward flight, then this will be a negative number.
 *
 * @group EKF2
 * @min -0.5
 * @max 0.5
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_PCOEF_XP, 0.0f);

/**
 * Static pressure position error coefficient for the negative X axis.
 *
 * This is the ratio of static pressure error to dynamic pressure generated by a negative wind relative velocity along the X body axis.
 * If the baro height estimate rises during backwards flight, then this will be a negative number.
 *
 * @group EKF2
 * @min -0.5
 * @max 0.5
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_PCOEF_XN, 0.0f);

/**
 * Pressure position error coefficient for the positive Y axis.
 *
 * This is the ratio of static pressure error to dynamic pressure generated by a wind relative velocity along the positive Y (RH) body axis.
 * If the baro height estimate rises during sideways flight to the right, then this will be a negative number.
 *
 * @group EKF2
 * @min -0.5
 * @max 0.5
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_PCOEF_YP, 0.0f);

/**
 * Pressure position error coefficient for the negative Y axis.
 *
 * This is the ratio of static pressure error to dynamic pressure generated by a wind relative velocity along the negative Y (LH) body axis.
 * If the baro height estimate rises during sideways flight to the left, then this will be a negative number.
 *
 * @group EKF2
 * @min -0.5
 * @max 0.5
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_PCOEF_YN, 0.0f);

/**
 * Static pressure position error coefficient for the Z axis.
 *
 * This is the ratio of static pressure error to dynamic pressure generated by a wind relative velocity along the Z body axis.
 *
 * @group EKF2
 * @min -0.5
 * @max 0.5
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_PCOEF_Z, 0.0f);

/**
 * Accelerometer bias learning limit.
 *
 * The ekf delta velocity bias states will be limited to within a range equivalent to +- of this value.
 *
 * @group EKF2
 * @min 0.0
 * @max 0.8
 * @unit m/s^2
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_ABL_LIM, 0.4f);

/**
 * Maximum IMU accel magnitude that allows IMU bias learning.
 *
 * If the magnitude of the IMU accelerometer vector exceeds this value, the EKF delta velocity state estimation will be inhibited.
 * This reduces the adverse effect of high manoeuvre accelerations and IMU nonlinerity and scale factor errors on the delta velocity bias estimates.
 *
 * @group EKF2
 * @min 20.0
 * @max 200.0
 * @unit m/s^2
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_ABL_ACCLIM, 25.0f);

/**
 * Maximum IMU gyro angular rate magnitude that allows IMU bias learning.
 *
 * If the magnitude of the IMU angular rate vector exceeds this value, the EKF delta velocity state estimation will be inhibited.
 * This reduces the adverse effect of rapid rotation rates and associated errors on the delta velocity bias estimates.
 *
 * @group EKF2
 * @min 2.0
 * @max 20.0
 * @unit rad/s
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_ABL_GYRLIM, 3.0f);

/**
 * Time constant used by acceleration and angular rate magnitude checks used to inhibit delta velocity bias learning.
 *
 * The vector magnitude of angular rate and acceleration used to check if learning should be inhibited has a peak hold filter applied to it with an exponential decay.
 * This parameter controls the time constant of the decay.
 *
 * @group EKF2
 * @min 0.1
 * @max 1.0
 * @unit s
 * @decimal 2
 */
PARAM_DEFINE_FLOAT(EKF2_ABL_TAU, 0.5f);

/**
 * Vehicle movement test threshold
 *
 * Scales the threshold tests applied to IMU data used to determine if the vehicle is static or moving. See parameter descriptions for EKF2_GPS_CHECK and EKF2_MAG_TYPE for further information on the functionality affected by this parameter.
 *
 * @group EKF2
 * @min 0.1
 * @max 10.0
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_MOVE_TEST, 1.0f);

/**
 * Required GPS health time on startup
 *
 * Minimum continuous period without GPS failure required to mark a healthy GPS status.
 * It can be reduced to speed up initialization, but it's recommended to keep this unchanged for a vehicle.
 *
 * @group EKF2
 * @min 0.1
 * @decimal 1
 * @unit s
 * @reboot_required true
 */
PARAM_DEFINE_FLOAT(EKF2_REQ_GPS_H, 10.0f);

/**
 * Magnetic field strength test selection
 *
 * When set, the EKF checks the strength of the magnetic field
 * to decide whether the magnetometer data is valid.
 * If GPS data is received, the magnetic field is compared to a World
 * Magnetic Model (WMM), otherwise an average value is used.
 * This check is useful to reject occasional hard iron disturbance.
 *
 * @group EKF2
 * @boolean
 */
PARAM_DEFINE_INT32(EKF2_MAG_CHECK, 0);

/**
 * Enable synthetic magnetometer Z component measurement.
 *
 * Use for vehicles where the measured body Z magnetic field is subject to strong magnetic interference.
 * For magnetic heading fusion the magnetometer Z measurement will be replaced by a synthetic value calculated
 * using the knowledge of the 3D magnetic field vector at the location of the drone. Therefore, this parameter
 * will only have an effect if the global position of the drone is known.
 * For 3D mag fusion the magnetometer Z measurement will simply be ingored instead of fusing the synthetic value.
 *
 * @group EKF2
 * @boolean
*/
PARAM_DEFINE_INT32(EKF2_SYNT_MAG_Z, 0);

/**
 * Default value of true airspeed used in EKF-GSF AHRS calculation.
 *
 * If no airspeed measurements are avalable, the EKF-GSF AHRS calculation will assume this value of true airspeed when compensating for centripetal acceleration during turns. Set to zero to disable centripetal acceleration compensation during fixed wing flight modes.
 *
 * @group EKF2
 * @min 0.0
 * @unit m/s
 * @max 100.0
 * @decimal 1
 */
PARAM_DEFINE_FLOAT(EKF2_GSF_TAS, 15.0f);