OBSTACLE_DISTANCE: add higher angle resolution and angle offset (#1142)

message_definitions/v1.0/common.xml

@@ -5016,10 +5016,13 @@
       <description>Obstacle distances in front of the sensor, starting from the left in increment degrees to the right</description>
       <field type="uint64_t" name="time_usec" units="us">Timestamp (UNIX Epoch time or time since system boot). The receiving end can infer timestamp format (since 1.1.1970 or since system boot) by checking for the magnitude the number.</field>
       <field type="uint8_t" name="sensor_type" enum="MAV_DISTANCE_SENSOR">Class id of the distance sensor type.</field>
-      <field type="uint16_t[72]" name="distances" units="cm">Distance of obstacles around the UAV with index 0 corresponding to local North. A value of 0 means that the obstacle is right in front of the sensor. A value of max_distance +1 means no obstacle is present. A value of UINT16_MAX for unknown/not used. In a array element, one unit corresponds to 1cm.</field>
-      <field type="uint8_t" name="increment" units="deg">Angular width in degrees of each array element.</field>
+      <field type="uint16_t[72]" name="distances" units="cm">Distance of obstacles around the UAV with index 0 corresponding to local forward + angle_offset. A value of 0 means that the obstacle is right in front of the sensor. A value of max_distance +1 means no obstacle is present. A value of UINT16_MAX for unknown/not used. In a array element, one unit corresponds to 1cm.</field>
+      <field type="uint8_t" name="increment" units="deg">Angular width in degrees of each array element. (Ignored if increment_f greater than 0).</field>
       <field type="uint16_t" name="min_distance" units="cm">Minimum distance the sensor can measure.</field>
       <field type="uint16_t" name="max_distance" units="cm">Maximum distance the sensor can measure.</field>
+      <extensions/>
+      <field type="float" name="increment_f" units="deg">Angular width in degrees of each array element as a float. If greater than 0 then this value is used instead of the uint8_t increment field.</field>
+      <field type="float" name="angle_offset" units="deg">Relative angle offset of the 0-index element in the distances array. Value of 0 corresponds to forward. Positive values are offsets to the right.</field>
     </message>
     <message id="331" name="ODOMETRY">
       <description>Odometry message to communicate odometry information with an external interface. Fits ROS REP 147 standard for aerial vehicles (http://www.ros.org/reps/rep-0147.html).</description>