diff --git a/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_main.cpp b/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_main.cpp
index db0ef62280..36e82db43b 100755
--- a/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_main.cpp
+++ b/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_main.cpp
@@ -276,6 +276,9 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 	float gyro_offsets[3] = { 0.0f, 0.0f, 0.0f };
 	unsigned offset_count = 0;
 
+	/* actual acceleration (by GPS velocity) in body frame */
+	float acc[3] = { 0.0f, 0.0f, 0.0f };
+
 	/* rotation matrix for magnetic declination */
 	math::Matrix<3, 3> R_decl;
 	R_decl.identity();
@@ -371,7 +374,6 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 						sensor_last_timestamp[1] = raw.timestamp;
 					}
 
-					float acc[3];
 					if (gps.fix_type >= 3 && gps.eph_m < 10.0f && gps.vel_ned_valid && hrt_absolute_time() < gps.timestamp_velocity + 500000) {
 						if (last_gps != 0 && gps.timestamp_velocity != last_gps) {
 							float gps_dt = (gps.timestamp_velocity - last_gps) / 1000000.0f;
@@ -388,20 +390,18 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 									acc[i] += att.R[j][i] * acc_NED[j];
 								}
 							}
+
+							vel_prev[0] = gps.vel_n_m_s;
+							vel_prev[1] = gps.vel_e_m_s;
+							vel_prev[2] = gps.vel_d_m_s;
 						}
+						last_gps = gps.timestamp_velocity;
 
 					} else {
 						acc[0] = 0.0f;
 						acc[1] = 0.0f;
 						acc[2] = 0.0f;
-					}
 
-					if (gps.vel_ned_valid) {
-						vel_prev[0] = gps.vel_n_m_s;
-						vel_prev[1] = gps.vel_e_m_s;
-						vel_prev[2] = gps.vel_d_m_s;
-						last_gps = gps.timestamp_velocity;
-					} else {
 						vel_prev[0] = 0.0f;
 						vel_prev[1] = 0.0f;
 						vel_prev[2] = 0.0f;
@@ -481,7 +481,7 @@ const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
 						continue;
 					}
 
-					if (last_data > 0 && raw.timestamp - last_data > 12000)
+					if (last_data > 0 && raw.timestamp - last_data > 30000)
 						printf("[attitude estimator ekf] sensor data missed! (%llu)\n", raw.timestamp - last_data);
 
 					last_data = raw.timestamp;
diff --git a/src/modules/mavlink/mavlink_receiver.cpp b/src/modules/mavlink/mavlink_receiver.cpp
index b4f7f2dfef..f8694ef286 100644
--- a/src/modules/mavlink/mavlink_receiver.cpp
+++ b/src/modules/mavlink/mavlink_receiver.cpp
@@ -579,6 +579,7 @@ handle_message(mavlink_message_t *msg)
 			hil_gps.alt = gps.alt;
 			hil_gps.eph_m = (float)gps.eph * 1e-2f; // from cm to m
 			hil_gps.epv_m = (float)gps.epv * 1e-2f; // from cm to m
+			hil_gps.timestamp_variance = gps.time_usec;
 			hil_gps.s_variance_m_s = 5.0f;
 			hil_gps.p_variance_m = hil_gps.eph_m * hil_gps.eph_m;
 			hil_gps.vel_m_s = (float)gps.vel * 1e-2f; // from cm/s to m/s
@@ -590,6 +591,7 @@ handle_message(mavlink_message_t *msg)
 			if (heading_rad > M_PI_F)
 				heading_rad -= 2.0f * M_PI_F;
 
+			hil_gps.timestamp_velocity = gps.time_usec;
 			hil_gps.vel_n_m_s = gps.vn * 1e-2f; // from cm to m
 			hil_gps.vel_e_m_s = gps.ve * 1e-2f; // from cm to m
 			hil_gps.vel_d_m_s = gps.vd * 1e-2f; // from cm to m