RSBR

The Radar Shooting Bouncing Ray (RSBR) sensor provides ground truth hit point access to targets that are within the field-of-view of a simulated radar. The output of the sensor provides target intersection information at the resolution and field-of-view specified by the configuration.

Configuration

{
    "type": "RSBR",
    "listen_port": 8123,
    "location": {
        "x": 250.0,
        "y": 0.0,
        "z": 50.0
    },
    "rotation": {
        "pitch": 0.0,
        "roll": 0.0,
        "yaw": 0.0
    },
    "azi_fov": 45.0,
    "ele_fov": 45.0,
    "consider_ego": false,
    "consider_road": false,
    "road_sample_density": 1000.0,
    "max_bounce_count": 2,
    "sample_density": 1000.0,
    "scan_distance": 3000.0,
    "draw_los_lines": false,
    "draw_points": false,
    "draw_reflection_bounce": 1,
    "draw_reflection_lines": false,
    "draw_road_points": false,
}

• azi_fov: The horizontal field-of-view along the azimuth of the sensor in degrees.
• ele_fov: The vertical field-of-view along the elevation of the sensor in degrees.
• consider_ego: If set to true then the ego will reflect points the same as other actors.
• consider_road: If set to true then hit points from the road will also be sampled.
• road_sample_density: The density in cm^2 / point to sample the road.
• max_bounce_count: The total number of bounces to sample per ray.
• sample_density: The density in cm^2 / point to sample actors.
• scan_distance: The maximum distance the sensor will detect objects in centimeters.
• draw_los_lines: If true then the line-of-sight lines (direct path to sensor) will be drawn.
• draw_points: If true then the sample points for each actor will be drawn around the bounding box.
• draw_reflection_bounce: When draw_reflection_lines is true, this will be the bounce that is drawn for the lines (e.g. 1, 2, 3, etc.).
• draw_reflection_lines: If true then the reflection lines will be drawn for the selected bounce.
• draw_road_points: If true then the points sampled from the road will be drawn.

Raw Output

The RSBR dataframe contains a vector of RSBRHitPoints. The directions and normals are within the RSBR sensor's coordinate frame. Here is the information for a single hit point.

• distance: The magnitude of the vector from the sensor to the target in meters.
• point: The 3-D point for the final sample position in centimeters.
• direction: A unit vector representing the 3-D direction of the ray cast.
• normal: A unit vector representing the 3-D direction of the normal to the surface sampled.
• relative_velocity: The relative velocity of the target to the sensor in cm/s.
• roughness: The roughness value for the sampled surface used as a coefficient to intensity of returns for diffuse energy computations.
• dielectric_constant: The dielectric constant for the sampled surface used as an intensity of returns for specular energy computations.
• radial_velocity: The velocity of the sampled target across the azimuth direction in rads/s.
• reflection: The total reflection value off the sampled surface as a summation of specular and diffuse reflections. Units will be a percentage of the total reflection of the dielectric constant based on Snell's Law.
• point_id: The unique ID of this hit point.
• parent_point_id: The unique ID of the origin point that was the origin for this sample. A value of 0 indicates the point has no parent's and has an origin at the sensor.
• bounce_count: The total number of bounces from the sensor before the sampled surface was impacted.
• is_direct: If true then there exists a direct line of sight from this point to the sensor origin.
• in_fov: If true then this point falls within the original field-of-view of the sensor.
• object_id: The unique ID of the actor that was sampled.
• object_center: The center 3-D point of the actor that is sampled in centimeters.
• object_orientation: The orientation vector of the sampled actor as a quaternion.
• object_extents: The extents from the object_center of the sampled actor's bounding box in centimeters.
• isRoad: If true then the sampled actor was designated as a road surface.

NOTE: The lineage of a point is a graph and not a single ray bouncing. To trace a point's lineage just continually follow the parent_point_id up the chain until you reach a value of 0 indicating this is the origin position of the tree.