SITL: Add parameter for optical flow sensor noise

libraries/SITL/SITL.cpp

@@ -152,6 +152,10 @@ const AP_Param::GroupInfo SITL::var_info2[] = {
     AP_GROUPINFO("SHOVE_Y",     31, SITL,  shove.y, 0),
     AP_GROUPINFO("SHOVE_Z",     32, SITL,  shove.z, 0),
     AP_GROUPINFO("SHOVE_TIME",  33, SITL,  shove.t, 0),
+    
+    // optical flow sensor measurement noise in rad/sec
+    AP_GROUPINFO("FLOW_RND",   34, SITL,  flow_noise,  0.05f),
+
     AP_GROUPEND
 };
     

libraries/SITL/SITL.h

@@ -175,6 +175,7 @@ public:
     AP_Float speedup; // simulation speedup
     AP_Int8  odom_enable; // enable visual odomotry data
     AP_Int8  telem_baudlimit_enable; // enable baudrate limiting on links
+    AP_Float flow_noise; // optical flow measurement noise (rad/sec)
 
     // wind control
     enum WindType {