diff --git a/msg/vehicle_local_position.msg b/msg/vehicle_local_position.msg
index 259f05fbdb..6f42547e43 100644
--- a/msg/vehicle_local_position.msg
+++ b/msg/vehicle_local_position.msg
@@ -52,6 +52,10 @@ float32 ref_alt				# Reference altitude AMSL, (metres)
 # Distance to surface
 float32 dist_bottom			# Distance from from bottom surface to ground, (metres)
 bool dist_bottom_valid			# true if distance to bottom surface is valid
+uint8 dist_bottom_sensor_bitfield	# bitfield indicating what type of sensor is used to estimate dist_bottom
+uint8 DIST_BOTTOM_SENSOR_NONE = 0
+uint8 DIST_BOTTOM_SENSOR_RANGE = 1	# (1 << 0) a range sensor is used to estimate dist_bottom field
+uint8 DIST_BOTTOM_SENSOR_FLOW = 2	# (1 << 1) a flow sensor is used to estimate dist_bottom field (mostly fixed-wing use case)
 
 float32 eph				# Standard deviation of horizontal position error, (metres)
 float32 epv				# Standard deviation of vertical position error, (metres)