diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index ff1afcd135..f4d6238a49 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -358,6 +358,7 @@ AP_InertialSensor::AP_InertialSensor() :
         _delta_velocity_acc_dt[i] = 0;
 
         _delta_angle_acc[i].zero();
+        _delta_angle_acc_dt[i] = 0;
         _last_delta_angle[i].zero();
         _last_raw_gyro[i].zero();
     }
@@ -911,6 +912,7 @@ void AP_InertialSensor::update(void)
             _delta_velocity_acc[i].zero();
             _delta_velocity_acc_dt[i] = 0;
             _delta_angle_acc[i].zero();
+            _delta_angle_acc_dt[i] = 0;
         }
 
         // adjust health status if a sensor has a non-zero error count
@@ -1106,6 +1108,17 @@ float AP_InertialSensor::get_delta_velocity_dt(uint8_t i) const
     return get_delta_time();
 }
 
+/*
+  return delta_time for the delta_angle
+ */
+float AP_InertialSensor::get_delta_angle_dt(uint8_t i) const
+{
+    if (_delta_angle_valid[i]) {
+        return _delta_angle_dt[i];
+    }
+    return get_delta_time();
+}
+
 
 /*
   support for setting accel and gyro vectors, for use by HIL
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.h b/libraries/AP_InertialSensor/AP_InertialSensor.h
index f299203dcb..fff8ba44d1 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.h
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.h
@@ -99,6 +99,9 @@ public:
     bool get_delta_angle(uint8_t i, Vector3f &delta_angle) const;
     bool get_delta_angle(Vector3f &delta_angle) const { return get_delta_angle(_primary_gyro, delta_angle); }
 
+    float get_delta_angle_dt(uint8_t i) const;
+    float get_delta_angle_dt() const { return get_delta_angle_dt(_primary_accel); }
+    
     //get delta velocity if available
     bool get_delta_velocity(uint8_t i, Vector3f &delta_velocity) const;
     bool get_delta_velocity(Vector3f &delta_velocity) const { return get_delta_velocity(_primary_accel, delta_velocity); }
@@ -302,7 +305,10 @@ private:
     // Most recent gyro reading
     Vector3f _gyro[INS_MAX_INSTANCES];
     Vector3f _delta_angle[INS_MAX_INSTANCES];
+    float _delta_angle_dt[INS_MAX_INSTANCES];
     bool _delta_angle_valid[INS_MAX_INSTANCES];
+    // time accumulator for delta angle accumulator
+    float _delta_angle_acc_dt[INS_MAX_INSTANCES];
     Vector3f _delta_angle_acc[INS_MAX_INSTANCES];
     Vector3f _last_delta_angle[INS_MAX_INSTANCES];
     Vector3f _last_raw_gyro[INS_MAX_INSTANCES];
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
index 8e7355e10a..fbe54e5b31 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
@@ -54,6 +54,7 @@ void AP_InertialSensor_Backend::_publish_gyro(uint8_t instance, const Vector3f &
 
     // publish delta angle
     _imu._delta_angle[instance] = _imu._delta_angle_acc[instance];
+    _imu._delta_angle_dt[instance] = _imu._delta_angle_acc_dt[instance];
     _imu._delta_angle_valid[instance] = true;
 }
 
@@ -87,6 +88,7 @@ void AP_InertialSensor_Backend::_notify_new_gyro_raw_sample(uint8_t instance,
     // referenced paper, but in simulation little difference was found between
     // integrating together and integrating separately (see examples/coning.py)
     _imu._delta_angle_acc[instance] += delta_angle + delta_coning;
+    _imu._delta_angle_acc_dt[instance] += dt;
 
     // save previous delta angle for coning correction
     _imu._last_delta_angle[instance] = delta_angle;