Request for terrain data and terrain status

                lat                       : Latitude of SW corner of first grid (degrees *10^7) (int32_t)
                lon                       : Longitude of SW corner of first grid (in degrees *10^7) (int32_t)
                grid_spacing              : Grid spacing in meters (uint16_t)
                mask                      : Bitmask of requested 4x4 grids (row major 8x7 array of grids, 56 bits) (uint64_t)

def terrain_request_send(self, lat, lon, grid_spacing, mask, force_mavlink1=False):
                '''
                Request for terrain data and terrain status

                lat                       : Latitude of SW corner of first grid (degrees *10^7) (int32_t)
                lon                       : Longitude of SW corner of first grid (in degrees *10^7) (int32_t)
                grid_spacing              : Grid spacing in meters (uint16_t)
                mask                      : Bitmask of requested 4x4 grids (row major 8x7 array of grids, 56 bits) (uint64_t)

                '''
                return self.send(self.terrain_request_encode(lat, lon, grid_spacing, mask), force_mavlink1=force_mavlink1)