AP_NavEKF3: fixed typos

libraries/AP_NavEKF3/AP_NavEKF3.cpp

@@ -184,7 +184,7 @@ const AP_Param::GroupInfo NavEKF3::var_info[] = {
     AP_GROUPINFO("GLITCH_RAD", 7, NavEKF3, _gpsGlitchRadiusMax, GLITCH_RADIUS_DEFAULT),
 
     // 8 previously used for EKF3_GPS_DELAY parameter that has been deprecated.
-    // The EKF now takes its GPs delay form the GPS library with the default delays
+    // The EKF now takes its GPS delay form the GPS library with the default delays
     // specified by the GPS_DELAY and GPS_DELAY2 parameters.
 
     // Height measurement parameters
@@ -681,7 +681,7 @@ bool NavEKF3::InitialiseFilter(void)
 
     // Set up any cores that have been created
     // This specifies the IMU to be used and creates the data buffers
-    // If we are unble to set up a core, return false and try again next time the function is called
+    // If we are unable to set up a core, return false and try again next time the function is called
     bool core_setup_success = true;
     for (uint8_t core_index=0; core_index<num_cores; core_index++) {
         if (coreSetupRequired[core_index]) {
@@ -849,7 +849,7 @@ void NavEKF3::getVelNED(int8_t instance, Vector3f &vel) const
 float NavEKF3::getPosDownDerivative(int8_t instance) const
 {
     if (instance < 0 || instance >= num_cores) instance = primary;
-    // return the value calculated from a complementary filer applied to the EKF height and vertical acceleration
+    // return the value calculated from a complementary filter applied to the EKF height and vertical acceleration
     if (core) {
         return core[instance].getPosDownDerivative();
     }
@@ -903,7 +903,7 @@ void NavEKF3::resetGyroBias(void)
 
 // Resets the baro so that it reads zero at the current height
 // Resets the EKF height to zero
-// Adjusts the EKf origin height so that the EKF height + origin height is the same as before
+// Adjusts the EKF origin height so that the EKF height + origin height is the same as before
 // Returns true if the height datum reset has been performed
 // If using a range finder for height no reset is performed and it returns false
 bool NavEKF3::resetHeightDatum(void)
@@ -1015,7 +1015,7 @@ bool NavEKF3::getLLH(struct Location &loc) const
 }
 
 // Return the latitude and longitude and height used to set the NED origin for the specified instance
-// An out of range instance (eg -1) returns data for the the primary instance
+// An out of range instance (eg -1) returns data for the primary instance
 // All NED positions calculated by the filter are relative to this location
 // Returns false if the origin has not been set
 bool NavEKF3::getOriginLLH(int8_t instance, struct Location &loc) const

libraries/AP_NavEKF3/AP_NavEKF3.h

@@ -69,23 +69,23 @@ public:
     int8_t getPrimaryCoreIMUIndex(void) const;
 
     // Write the last calculated NE position relative to the reference point (m) for the specified instance.
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     // If a calculated solution is not available, use the best available data and return false
     // If false returned, do not use for flight control
     bool getPosNE(int8_t instance, Vector2f &posNE) const;
 
     // Write the last calculated D position relative to the reference point (m) for the specified instance.
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     // If a calculated solution is not available, use the best available data and return false
     // If false returned, do not use for flight control
     bool getPosD(int8_t instance, float &posD) const;
 
     // return NED velocity in m/s for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getVelNED(int8_t instance, Vector3f &vel) const;
 
     // Return the rate of change of vertical position in the down direction (dPosD/dt) in m/s for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     // This can be different to the z component of the EKF velocity state because it will fluctuate with height errors and corrections in the EKF
     // but will always be kinematically consistent with the z component of the EKF position state
     float getPosDownDerivative(int8_t instance) const;
@@ -94,15 +94,15 @@ public:
     void getAccelNED(Vector3f &accelNED) const;
 
     // return body axis gyro bias estimates in rad/sec for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getGyroBias(int8_t instance, Vector3f &gyroBias) const;
 
     // return accelerometer bias estimate in m/s/s
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getAccelBias(int8_t instance, Vector3f &accelBias) const;
 
     // return tilt error convergence metric for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getTiltError(int8_t instance, float &ang) const;
 
     // reset body axis gyro bias estimates
@@ -110,7 +110,7 @@ public:
 
     // Resets the baro so that it reads zero at the current height
     // Resets the EKF height to zero
-    // Adjusts the EKf origin height so that the EKF height + origin height is the same as before
+    // Adjusts the EKF origin height so that the EKF height + origin height is the same as before
     // Returns true if the height datum reset has been performed
     // If using a range finder for height no reset is performed and it returns false
     bool resetHeightDatum(void);
@@ -130,19 +130,19 @@ public:
     void getEkfControlLimits(float &ekfGndSpdLimit, float &ekfNavVelGainScaler) const;
 
     // return the NED wind speed estimates in m/s (positive is air moving in the direction of the axis)
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getWind(int8_t instance, Vector3f &wind) const;
 
     // return earth magnetic field estimates in measurement units / 1000 for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getMagNED(int8_t instance, Vector3f &magNED) const;
 
     // return body magnetic field estimates in measurement units / 1000 for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getMagXYZ(int8_t instance, Vector3f &magXYZ) const;
 
     // return the magnetometer in use for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     uint8_t getActiveMag(int8_t instance) const;
 
     // Return estimated magnetometer offsets
@@ -156,7 +156,7 @@ public:
     bool getLLH(struct Location &loc) const;
 
     // Return the latitude and longitude and height used to set the NED origin for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     // All NED positions calculated by the filter are relative to this location
     // Returns false if the origin has not been set
     bool getOriginLLH(int8_t instance, struct Location &loc) const;
@@ -172,7 +172,7 @@ public:
     bool getHAGL(float &HAGL) const;
 
     // return the Euler roll, pitch and yaw angle in radians for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getEulerAngles(int8_t instance, Vector3f &eulers) const;
 
     // return the transformation matrix from XYZ (body) to NED axes
@@ -182,14 +182,14 @@ public:
     void getQuaternion(int8_t instance, Quaternion &quat) const;
 
     // return the innovations for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getInnovations(int8_t index, Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const;
 
     // publish output observer angular, velocity and position tracking error
     void getOutputTrackingError(int8_t instance, Vector3f &error) const;
 
     // return the innovation consistency test ratios for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getVariances(int8_t instance, float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const;
 
     // return the diagonals from the covariance matrix for the specified instance
@@ -242,7 +242,7 @@ public:
     uint32_t getBodyFrameOdomDebug(int8_t instance, Vector3f &velInnov, Vector3f &velInnovVar) const;
 
     // return data for debugging optical flow fusion for the specified instance
-    // An out of range instance (eg -1) returns data for the the primary instance
+    // An out of range instance (eg -1) returns data for the primary instance
     void getFlowDebug(int8_t instance, float &varFlow, float &gndOffset, float &flowInnovX, float &flowInnovY, float &auxInnov, float &HAGL, float &rngInnov, float &range, float &gndOffsetErr) const;
 
     /*
@@ -277,7 +277,7 @@ public:
 
     /*
     return the filter fault status as a bitmasked integer for the specified instance
-    An out of range instance (eg -1) returns data for the the primary instance
+    An out of range instance (eg -1) returns data for the primary instance
      0 = quaternions are NaN
      1 = velocities are NaN
      2 = badly conditioned X magnetometer fusion
@@ -291,7 +291,7 @@ public:
 
     /*
     return filter timeout status as a bitmasked integer for the specified instance
-    An out of range instance (eg -1) returns data for the the primary instance
+    An out of range instance (eg -1) returns data for the primary instance
      0 = position measurement timeout
      1 = velocity measurement timeout
      2 = height measurement timeout
@@ -305,13 +305,13 @@ public:
 
     /*
     return filter gps quality check status for the specified instance
-    An out of range instance (eg -1) returns data for the the primary instance
+    An out of range instance (eg -1) returns data for the primary instance
     */
     void getFilterGpsStatus(int8_t instance, nav_gps_status &faults) const;
 
     /*
     return filter status flags for the specified instance
-    An out of range instance (eg -1) returns data for the the primary instance
+    An out of range instance (eg -1) returns data for the primary instance
     */
     void getFilterStatus(int8_t instance, nav_filter_status &status) const;
 
@@ -411,7 +411,7 @@ private:
     AP_Int8  _rngBcnDelay_ms;       // effective average delay of range beacon measurements rel to IMU (msec)
     AP_Float _useRngSwSpd;          // Maximum horizontal ground speed to use range finder as the primary height source (m/s)
     AP_Float _accBiasLim;           // Accelerometer bias limit (m/s/s)
-    AP_Int8 _magMask;               // Bitmask forcng specific EKF core instances to use simple heading magnetometer fusion.
+    AP_Int8 _magMask;               // Bitmask forcing specific EKF core instances to use simple heading magnetometer fusion.
     AP_Int8 _originHgtMode;         // Bitmask controlling post alignment correction and reporting of the EKF origin height.
     AP_Float _visOdmVelErrMax;      // Observation 1-STD velocity error assumed for visual odometry sensor at lowest reported quality (m/s)
     AP_Float _visOdmVelErrMin;      // Observation 1-STD velocity error assumed for visual odometry sensor at highest reported quality (m/s)

libraries/AP_NavEKF3/AP_NavEKF3_AirDataFusion.cpp

@@ -186,7 +186,7 @@ void NavEKF3_core::FuseAirspeed()
         }
     }
 
-    // force the covariance matrix to me symmetrical and limit the variances to prevent ill-condiioning.
+    // force the covariance matrix to be symmetrical and limit the variances to prevent ill-conditioning.
     ForceSymmetry();
     ConstrainVariances();
 
@@ -454,7 +454,7 @@ void NavEKF3_core::FuseSideslip()
         }
     }
 
-    // force the covariance matrix to be symmetrical and limit the variances to prevent ill-condiioning.
+    // force the covariance matrix to be symmetrical and limit the variances to prevent ill-conditioning.
     ForceSymmetry();
     ConstrainVariances();
 

libraries/AP_NavEKF3/AP_NavEKF3_Control.cpp

@@ -83,7 +83,7 @@ void NavEKF3_core::setWindMagStateLearningMode()
         }
     }
 
-    // determine if the vehicle is manoevring
+    // determine if the vehicle is manoeuvring
     if (accNavMagHoriz > 0.5f) {
         manoeuvring = true;
     } else {
@@ -301,7 +301,7 @@ void NavEKF3_core::setAidingMode()
 
     // check to see if we are starting or stopping aiding and set states and modes as required
     if (PV_AidingMode != PV_AidingModePrev) {
-        // set various  usage modes based on the condition when we start aiding. These are then held until aiding is stopped.
+        // set various usage modes based on the condition when we start aiding. These are then held until aiding is stopped.
         switch (PV_AidingMode) {
         case AID_NONE:
             // We have ceased aiding
@@ -427,7 +427,7 @@ bool NavEKF3_core::readyToUseBodyOdm(void) const
     bool wencDataGood = (imuSampleTime_ms - wheelOdmMeasTime_ms < 200);
 
     // We require stable roll/pitch angles and gyro bias estimates but do not need the yaw angle aligned to use odometry measurements
-    // becasue they are in a body frame of reference
+    // because they are in a body frame of reference
     return (visoDataGood || wencDataGood)
             && tiltAlignComplete
             && delAngBiasLearned;

libraries/AP_NavEKF3/AP_NavEKF3_MagFusion.cpp

@@ -80,7 +80,7 @@ void NavEKF3_core::controlMagYawReset()
     magYawResetRequest = magYawResetRequest || // an external request
             initialResetRequest || // an initial alignment performed by all vehicle types using magnetometer
             interimResetRequest || // an interim alignment required to recover from ground based magnetic anomaly
-            finalResetRequest; // the final reset when we have acheived enough height to be in stable magnetic field environment
+            finalResetRequest; // the final reset when we have achieved enough height to be in stable magnetic field environment
 
     // Perform a reset of magnetic field states and reset yaw to corrected magnetic heading
     if (magYawResetRequest || magStateResetRequest) {
@@ -111,7 +111,7 @@ void NavEKF3_core::controlMagYawReset()
             // reset the quaternion covariances using the rotation vector variances
             initialiseQuatCovariances(angleErrVarVec);
 
-            // calculate the change in the quaternion state and apply it to the ouput history buffer
+            // calculate the change in the quaternion state and apply it to the output history buffer
             prevQuat = stateStruct.quat/prevQuat;
             StoreQuatRotate(prevQuat);
 
@@ -200,7 +200,7 @@ void NavEKF3_core::realignYawGPS()
             magYawResetRequest = false;
 
             if (use_compass()) {
-                // request a mag field reset which may enable us to use the magnetoemter if the previous fault was due to bad initialisation
+                // request a mag field reset which may enable us to use the magnetometer if the previous fault was due to bad initialisation
                 magStateResetRequest = true;
                 // clear the all sensors failed status so that the magnetometers sensors get a second chance now that we are flying
                 allMagSensorsFailed = false;
@@ -219,7 +219,7 @@ void NavEKF3_core::SelectMagFusion()
     // start performance timer
     hal.util->perf_begin(_perf_FuseMagnetometer);
 
-    // clear the flag that lets other processes know that the expensive magnetometer fusion operation has been perfomred on that time step
+    // clear the flag that lets other processes know that the expensive magnetometer fusion operation has been performed on that time step
     // used for load levelling
     magFusePerformed = false;
 
@@ -584,7 +584,7 @@ void NavEKF3_core::FuseMagnetometer()
                 memset(&Kfusion[22], 0, 8);
             }
 
-            // set flags to indicate to other processes that fusion has been performede and is required on the next frame
+            // set flags to indicate to other processes that fusion has been performed and is required on the next frame
             // this can be used by other fusion processes to avoid fusing on the same frame as this expensive step
             magFusePerformed = true;
             magFuseRequired = true;
@@ -660,7 +660,7 @@ void NavEKF3_core::FuseMagnetometer()
                 memset(&Kfusion[22], 0, 8);
             }
 
-            // set flags to indicate to other processes that fusion has been performede and is required on the next frame
+            // set flags to indicate to other processes that fusion has been performed and is required on the next frame
             // this can be used by other fusion processes to avoid fusing on the same frame as this expensive step
             magFusePerformed = true;
         }
@@ -712,7 +712,7 @@ void NavEKF3_core::FuseMagnetometer()
                 }
             }
 
-            // force the covariance matrix to be symmetrical and limit the variances to prevent ill-condiioning.
+            // force the covariance matrix to be symmetrical and limit the variances to prevent ill-conditioning.
             ForceSymmetry();
             ConstrainVariances();
 
@@ -745,7 +745,7 @@ void NavEKF3_core::FuseMagnetometer()
  * This fusion method only modifies the orientation, does not require use of the magnetic field states and is computationally cheaper.
  * It is suitable for use when the external magnetic field environment is disturbed (eg close to metal structures, on ground).
  * It is not as robust to magnetometer failures.
- * It is not suitable for operation where the horizontal magnetic field strength is weak (within 30 degrees latitude of the the magnetic poles)
+ * It is not suitable for operation where the horizontal magnetic field strength is weak (within 30 degrees latitude of the magnetic poles)
 */
 void NavEKF3_core::fuseEulerYaw()
 {
@@ -946,7 +946,7 @@ void NavEKF3_core::fuseEulerYaw()
             }
         }
 
-        // force the covariance matrix to be symmetrical and limit the variances to prevent ill-condiioning.
+        // force the covariance matrix to be symmetrical and limit the variances to prevent ill-conditioning.
         ForceSymmetry();
         ConstrainVariances();
 
@@ -1124,7 +1124,7 @@ void NavEKF3_core::FuseDeclination(float declErr)
             }
         }
 
-        // force the covariance matrix to be symmetrical and limit the variances to prevent ill-condiioning.
+        // force the covariance matrix to be symmetrical and limit the variances to prevent ill-conditioning.
         ForceSymmetry();
         ConstrainVariances();
 

libraries/AP_NavEKF3/AP_NavEKF3_Measurements.cpp

@@ -136,7 +136,7 @@ void NavEKF3_core::writeWheelOdom(float delAng, float delTime, uint32_t timeStam
 {
     // This is a simple hack to get wheel encoder data into the EKF and verify the interface sign conventions and units
     // It uses the exisiting body frame velocity fusion.
-    // TODO implement a dedicated wheel odometry observaton model
+    // TODO implement a dedicated wheel odometry observation model
 
     // limit update rate to maximum allowed by sensor buffers and fusion process
     // don't try to write to buffer until the filter has been initialised
@@ -150,7 +150,7 @@ void NavEKF3_core::writeWheelOdom(float delAng, float delTime, uint32_t timeStam
     wheelOdmDataNew.delTime = delTime;
     wheelOdmMeasTime_ms = timeStamp_ms;
 
-    // becasue we are currently converting to an equivalent velocity measurement before fusing
+    // because we are currently converting to an equivalent velocity measurement before fusing
     // the measurement time is moved back to the middle of the sampling period
     wheelOdmDataNew.time_ms = timeStamp_ms - (uint32_t)(500.0f * delTime);
 
@@ -558,7 +558,7 @@ void NavEKF3_core::readGpsData()
             // Read the GPS location in WGS-84 lat,long,height coordinates
             const struct Location &gpsloc = gps.location();
 
-            // Set the EKF origin and magnetic field declination if not previously set  and GPS checks have passed
+            // Set the EKF origin and magnetic field declination if not previously set and GPS checks have passed
             if (gpsGoodToAlign && !validOrigin) {
                 setOrigin();
 

libraries/AP_NavEKF3/AP_NavEKF3_OptFlowFusion.cpp

@@ -77,7 +77,7 @@ void NavEKF3_core::SelectFlowFusion()
 
 /*
 Estimation of terrain offset using a single state EKF
-The filter can fuse motion compensated optiocal flow rates and range finder measurements
+The filter can fuse motion compensated optical flow rates and range finder measurements
 */
 void NavEKF3_core::EstimateTerrainOffset()
 {
@@ -315,7 +315,7 @@ void NavEKF3_core::FuseOptFlow()
         // calculate relative velocity in sensor frame including the relative motion due to rotation
         relVelSensor = (prevTnb * stateStruct.velocity) + (ofDataDelayed.bodyRadXYZ % posOffsetBody);
 
-        // divide velocity by range  to get predicted angular LOS rates relative to X and Y axes
+        // divide velocity by range to get predicted angular LOS rates relative to X and Y axes
         losPred[0] =  relVelSensor.y/range;
         losPred[1] = -relVelSensor.x/range;
 
@@ -332,7 +332,7 @@ void NavEKF3_core::FuseOptFlow()
             H_LOS[5] = t2*(q0*q0-q1*q1+q2*q2-q3*q3);
             H_LOS[6] = t2*(q0*q1*2.0f+q2*q3*2.0f);
 
-            // calculate intermediate variables for the X observaton innovatoin variance and Kalman gains
+            // calculate intermediate variables for the X observation innovation variance and Kalman gains
             float t3 = q1*vd*2.0f;
             float t4 = q0*ve*2.0f;
             float t11 = q3*vn*2.0f;
@@ -503,7 +503,7 @@ void NavEKF3_core::FuseOptFlow()
             H_LOS[5] = -t2*(q0*q3*2.0f+q1*q2*2.0f);
             H_LOS[6] = t2*(q0*q2*2.0f-q1*q3*2.0f);
 
-            // calculate intermediate variables for the Y observaton innovatoin variance and Kalman gains
+            // calculate intermediate variables for the Y observation innovation variance and Kalman gains
             float t3 = q3*ve*2.0f;
             float t4 = q0*vn*2.0f;
             float t11 = q2*vd*2.0f;
@@ -597,8 +597,7 @@ void NavEKF3_core::FuseOptFlow()
             float t77 = R_LOS+t37+t43+t56+t63+t70-t85-t94;
             float t78;
 
-            // calculate innovation variance for X axis observation and protect against a badly conditioned calculation
-            // calculate innovation variance for X axis observation and protect against a badly conditioned calculation
+            // calculate innovation variance for Y axis observation and protect against a badly conditioned calculation
             if (t77 > R_LOS) {
                 t78 = 1.0f/t77;
                 faultStatus.bad_yflow = false;
@@ -717,7 +716,7 @@ void NavEKF3_core::FuseOptFlow()
                     }
                 }
 
-                // force the covariance matrix to be symmetrical and limit the variances to prevent ill-condiioning.
+                // force the covariance matrix to be symmetrical and limit the variances to prevent ill-conditioning.
                 ForceSymmetry();
                 ConstrainVariances();
 

libraries/AP_NavEKF3/AP_NavEKF3_Outputs.cpp

@@ -218,7 +218,7 @@ void NavEKF3_core::getVelNED(Vector3f &vel) const
     vel = outputDataNew.velocity + velOffsetNED;
 }
 
-// Return the rate of change of vertical position in the down diection (dPosD/dt) of the body frame origin in m/s
+// Return the rate of change of vertical position in the down direction (dPosD/dt) of the body frame origin in m/s
 float NavEKF3_core::getPosDownDerivative(void) const
 {
     // return the value calculated from a complementary filter applied to the EKF height and vertical acceleration
@@ -328,7 +328,7 @@ bool NavEKF3_core::getLLH(struct Location &loc) const
             location_offset(loc, outputDataNew.position.x, outputDataNew.position.y);
             return true;
         } else {
-            // we could be in constant position mode  because the vehicle has taken off without GPS, or has lost GPS
+            // we could be in constant position mode because the vehicle has taken off without GPS, or has lost GPS
             // in this mode we cannot use the EKF states to estimate position so will return the best available data
             if ((gps.status() >= AP_GPS::GPS_OK_FIX_2D)) {
                 // we have a GPS position fix to return

libraries/AP_NavEKF3/AP_NavEKF3_PosVelFusion.cpp

@@ -429,7 +429,7 @@ void NavEKF3_core::FuseVelPosNED()
             }
             R_OBS[4] = R_OBS[3];
             // For data integrity checks we use the same measurement variances as used to calculate the Kalman gains for all measurements except GPS horizontal velocity
-            // For horizontal GPs velocity we don't want the acceptance radius to increase with reported GPS accuracy so we use a value based on best GPs perfomrance
+            // For horizontal GPS velocity we don't want the acceptance radius to increase with reported GPS accuracy so we use a value based on best GPS performance
             // plus a margin for manoeuvres. It is better to reject GPS horizontal velocity errors early
             for (uint8_t i=0; i<=2; i++) R_OBS_DATA_CHECKS[i] = sq(constrain_float(frontend->_gpsHorizVelNoise, 0.05f, 5.0f)) + sq(frontend->gpsNEVelVarAccScale * accNavMag);
         }
@@ -636,7 +636,7 @@ void NavEKF3_core::FuseVelPosNED()
                     memset(&Kfusion[10], 0, 12);
                 }
 
-                // inhibit delta velocity bias state estmation by setting Kalman gains to zero
+                // inhibit delta velocity bias state estimation by setting Kalman gains to zero
                 if (!inhibitDelVelBiasStates) {
                     for (uint8_t i = 13; i<=15; i++) {
                         Kfusion[i] = P[i][stateIndex]*SK;
@@ -688,7 +688,7 @@ void NavEKF3_core::FuseVelPosNED()
                         }
                     }
 
-                    // force the covariance matrix to be symmetrical and limit the variances to prevent ill-condiioning.
+                    // force the covariance matrix to be symmetrical and limit the variances to prevent ill-conditioning.
                     ForceSymmetry();
                     ConstrainVariances();
 
@@ -1522,7 +1522,7 @@ void NavEKF3_core::FuseBodyVel()
                     }
                 }
 
-                // force the covariance matrix to be symmetrical and limit the variances to prevent ill-condiioning.
+                // force the covariance matrix to be symmetrical and limit the variances to prevent ill-conditioning.
                 ForceSymmetry();
                 ConstrainVariances();
 

libraries/AP_NavEKF3/AP_NavEKF3_RngBcnFusion.cpp

@@ -100,7 +100,7 @@ void NavEKF3_core::FuseRngBcn()
         H_BCN[7] = -t4*t9;
         H_BCN[8] = -t3*t9;
         // If we are not using the beacons as a height reference, we pretend that the beacons
-        // are a the same height as the flight vehicle when calculating the observation derivatives
+        // are at the same height as the flight vehicle when calculating the observation derivatives
         // and Kalman gains
         // TODO  - less hacky way of achieving this, preferably using an alternative derivation
         if (activeHgtSource != HGT_SOURCE_BCN) {
@@ -247,7 +247,7 @@ void NavEKF3_core::FuseRngBcn()
                     }
                 }
 
-                // force the covariance matrix to be symmetrical and limit the variances to prevent ill-condiioning.
+                // force the covariance matrix to be symmetrical and limit the variances to prevent ill-conditioning.
                 ForceSymmetry();
                 ConstrainVariances();
 
@@ -335,7 +335,7 @@ void NavEKF3_core::FuseRngBcnStatic()
                 // We are using a different height reference for the main EKF so need to estimate a vertical
                 // position offset to be applied to the beacon system that minimises the range innovations
                 // The position estimate should be stable after 100 iterations so we use a simple dual
-                // hypothesis 1-state EKF to estiate the offset
+                // hypothesis 1-state EKF to estimate the offset
                 Vector3f refPosNED;
                 refPosNED.x = receiverPos.x;
                 refPosNED.y = receiverPos.y;

libraries/AP_NavEKF3/AP_NavEKF3_VehicleStatus.cpp

@@ -10,7 +10,7 @@ extern const AP_HAL::HAL& hal;
 
 
 /* Monitor GPS data to see if quality is good enough to initialise the EKF
-   Monitor magnetometer innovations to to see if the heading is good enough to use GPS
+   Monitor magnetometer innovations to see if the heading is good enough to use GPS
    Return true if all criteria pass for 10 seconds
 
    We also record the failure reason so that prearm_failure_reason()
@@ -45,7 +45,7 @@ bool NavEKF3_core::calcGpsGoodToAlign(void)
 
     const struct Location &gpsloc = gps.location(); // Current location
     const float posFiltTimeConst = 10.0f; // time constant used to decay position drift
-    // calculate time lapsesd since last update and limit to prevent numerical errors
+    // calculate time lapsed since last update and limit to prevent numerical errors
     float deltaTime = constrain_float(float(imuDataDelayed.time_ms - lastPreAlignGpsCheckTime_ms)*0.001f,0.01f,posFiltTimeConst);
     lastPreAlignGpsCheckTime_ms = imuDataDelayed.time_ms;
     // Sum distance moved
@@ -53,7 +53,7 @@ bool NavEKF3_core::calcGpsGoodToAlign(void)
     gpsloc_prev = gpsloc;
     // Decay distance moved exponentially to zero
     gpsDriftNE *= (1.0f - deltaTime/posFiltTimeConst);
-    // Clamp the fiter state to prevent excessive persistence of large transients
+    // Clamp the filter state to prevent excessive persistence of large transients
     gpsDriftNE = MIN(gpsDriftNE,10.0f);
     // Fail if more than 3 metres drift after filtering whilst on-ground
     // This corresponds to a maximum acceptable average drift rate of 0.3 m/s or single glitch event of 3m

libraries/AP_NavEKF3/AP_NavEKF3_core.cpp

@@ -616,7 +616,7 @@ void NavEKF3_core::correctDeltaVelocity(Vector3f &delVel, float delVelDT)
  * Update the quaternion, velocity and position states using delayed IMU measurements
  * because the EKF is running on a delayed time horizon. Note that the quaternion is
  * not used by the EKF equations, which instead estimate the error in the attitude of
- * the vehicle when each observtion is fused. This attitude error is then used to correct
+ * the vehicle when each observation is fused. This attitude error is then used to correct
  * the quaternion.
 */
 void NavEKF3_core::UpdateStrapdownEquationsNED()
@@ -1374,7 +1374,7 @@ void NavEKF3_core::StoreOutputReset()
         storedOutput[i] = outputDataNew;
     }
     outputDataDelayed = outputDataNew;
-    // reset the states for the complementary filter used to provide a vertical position dervative output
+    // reset the states for the complementary filter used to provide a vertical position derivative output
     posDown = stateStruct.position.z;
     posDownDerivative = stateStruct.velocity.z;
 }
@@ -1497,7 +1497,7 @@ void NavEKF3_core::ConstrainStates()
     for (uint8_t i=4; i<=6; i++) statesArray[i] = constrain_float(statesArray[i],-5.0e2f,5.0e2f);
     // position limit 1000 km - TODO apply circular limit
     for (uint8_t i=7; i<=8; i++) statesArray[i] = constrain_float(statesArray[i],-1.0e6f,1.0e6f);
-    // height limit covers home alt on everest through to home alt at SL and ballon drop
+    // height limit covers home alt on everest through to home alt at SL and balloon drop
     stateStruct.position.z = constrain_float(stateStruct.position.z,-4.0e4f,1.0e4f);
     // gyro bias limit (this needs to be set based on manufacturers specs)
     for (uint8_t i=10; i<=12; i++) statesArray[i] = constrain_float(statesArray[i],-GYRO_BIAS_LIMIT*dtEkfAvg,GYRO_BIAS_LIMIT*dtEkfAvg);
@@ -1524,7 +1524,7 @@ void NavEKF3_core::calcEarthRateNED(Vector3f &omega, int32_t latitude) const
     omega.z  = -earthRate*sinf(lat_rad);
 }
 
-// initialise the earth magnetic field states using declination, suppled roll/pitch
+// initialise the earth magnetic field states using declination, supplied roll/pitch
 // and magnetometer measurements and return initial attitude quaternion
 Quaternion NavEKF3_core::calcQuatAndFieldStates(float roll, float pitch)
 {
@@ -1596,7 +1596,7 @@ Quaternion NavEKF3_core::calcQuatAndFieldStates(float roll, float pitch)
         magStateResetRequest = false;
 
     } else {
-        // this function should not be called if there is no compass data but if is is, return the
+        // this function should not be called if there is no compass data but if it is, return the
         // current attitude
         initQuat = stateStruct.quat;
     }

libraries/AP_NavEKF3/AP_NavEKF3_core.h

@@ -121,7 +121,7 @@ public:
 
     // Resets the baro so that it reads zero at the current height
     // Resets the EKF height to zero
-    // Adjusts the EKf origin height so that the EKF height + origin height is the same as before
+    // Adjusts the EKF origin height so that the EKF height + origin height is the same as before
     // Returns true if the height datum reset has been performed
     // If using a range finder for height no reset is performed and it returns false
     bool resetHeightDatum(void);
@@ -211,7 +211,7 @@ public:
      * Write body frame linear and angular displacement measurements from a visual odometry sensor
      *
      * quality is a normalised confidence value from 0 to 100
-     * delPos is the XYZ change in linear position meaasured in body frame and relative to the inertial reference at time_ms (m)
+     * delPos is the XYZ change in linear position measured in body frame and relative to the inertial reference at time_ms (m)
      * delAng is the XYZ angular rotation measured in body frame and relative to the inertial reference at time_ms (rad)
      * delTime is the time interval for the measurement of delPos and delAng (sec)
      * timeStamp_ms is the timestamp of the last image used to calculate delPos and delAng (msec)
@@ -533,7 +533,7 @@ private:
     // fuse range beacon measurements
     void FuseRngBcn();
 
-    // use range beaon measurements to calculate a static position
+    // use range beacon measurements to calculate a static position
     void FuseRngBcnStatic();
 
     // calculate the offset from EKF vertical position datum to the range beacon system datum
@@ -545,7 +545,7 @@ private:
     // fuse true airspeed measurements
     void FuseAirspeed();
 
-    // fuse sythetic sideslip measurement of zero
+    // fuse synthetic sideslip measurement of zero
     void FuseSideslip();
 
     // zero specified range of rows in the state covariance matrix
@@ -636,7 +636,7 @@ private:
     // determine when to perform fusion of GPS position and  velocity measurements
     void SelectVelPosFusion();
 
-    // determine when to perform fusion of range measurements take realtive to a beacon at a known NED position
+    // determine when to perform fusion of range measurements take relative to a beacon at a known NED position
     void SelectRngBcnFusion();
 
     // determine when to perform fusion of magnetometer measurements
@@ -651,7 +651,7 @@ private:
     // force alignment of the yaw angle using GPS velocity data
     void realignYawGPS();
 
-    // initialise the earth magnetic field states using declination and current attitude and magnetometer meaasurements
+    // initialise the earth magnetic field states using declination and current attitude and magnetometer measurements
     // and return attitude quaternion
     Quaternion calcQuatAndFieldStates(float roll, float pitch);
 
@@ -712,7 +712,7 @@ private:
     // Determine if we are flying or on the ground
     void detectFlight();
 
-    // Set inertial navigaton aiding mode
+    // Set inertial navigation aiding mode
     void setAidingMode();
 
     // Determine if learning of wind and magnetic field will be enabled and set corresponding indexing limits to
@@ -961,7 +961,7 @@ private:
     Vector3f bodyMagFieldVar;       // XYZ body mag field variances for last learned field (mGauss^2)
     bool delAngBiasLearned;         // true when the gyro bias has been learned
     nav_filter_status filterStatus; // contains the status of various filter outputs
-    float ekfOriginHgtVar;          // Variance of the the EKF WGS-84 origin height estimate (m^2)
+    float ekfOriginHgtVar;          // Variance of the EKF WGS-84 origin height estimate (m^2)
     double ekfGpsRefHgt;            // floating point representation of the WGS-84 reference height used to convert GPS height to local height (m)
     uint32_t lastOriginHgtTime_ms;  // last time the ekf's WGS-84 origin height was corrected
     Vector3f outputTrackError;      // attitude (rad), velocity (m/s) and position (m) tracking error magnitudes from the output observer
@@ -981,7 +981,7 @@ private:
                     MAG=5,          // Use magnetometer data
                     RNGFND=6        // Use rangefinder data
                         };
-    resetDataSource posResetSource; // preferred soure of data for position reset
+    resetDataSource posResetSource; // preferred source of data for position reset
     resetDataSource velResetSource; // preferred source of data for a velocity reset
 
     // variables used to calculate a vertical velocity that is kinematically consistent with the vertical position