Point Cloud Data Specification#

This is a point cloud message from AkiraKan fusion box. This message will be sent out for each received LiDAR data frame (10Hz).

Communication Specification#

Item

Description

Communication Protocol

TCP (ZeroMQ PULL)

Data Encoding

FlatBuffers v2.0.0

Output Port

5558

PointCloudPacket#

Field

Uint

Data Type

Description

frame_id

-

uint16

ID / index of the LiDAR frame / scan. It is incremented every time the sensor completes a rotation, crossing the zero azimuth angle.

lidarts_ms

ms

float64

Timestamp from Ouster LiDAR Time Source.
If not synchronised to PTP time source:
monotonically increasing counter that will begin counting milliseconds since startup.
If synchronised to PTP time source:
As soon as a PTP sync event happens, the time will be updated to unix timestamp (milliseconds since 1970). The counter must always count forward in time. If another PTP sync event happens the counter will either jump forward to match the new time, or slow itself down.

unixts_ms

ms

float64

Unix timestamp (milliseconds since 1970) from AkiraKan fusion box

point_clouds

-

[PointCloud]

Vector of synchronized point cloud in the current time

PointCloud#

Field

Unit

Data type

Description

lidar_sn

-

uint64

Serial number of the sensor. This value is unique to each sensor and can be found on a sticker affixed to the base of the sensor.

attr_column

-

AttrType (uint8)

Column Attribute type

column_count

-

uint8

Number of columns - at least 3 columns when AttrType is NoAttr.

row_count

-

uint32

Number of points

point_cloud

-

[float32]

Vector of point cloud in row-major order with total length of column_count x row_count

AttrType#

Type

Enumeration

Data type

Description

NoAttr

0

uint8

Only output x, y, z column without attributes

Range

1

uint8

Output Range only - range in millimeters, discretized to the nearest 1 millimeters.

Reflectivity

2

uint8

Output Calibrated Reflectivity only - sensor Signal Photons measurements are scaled based on measured range and sensor sensitivity at that range, providing an indication of target reflectivity.

SignalPhotons

3

uint8

Output Signal Photons only - signal intensity photons in the signal return measurement are reported.

NIRPhotons

4

uint8

Output Near Infrared Photons only - NIR photons related to natural environmental illumination are reported.

ReflectivityNIR

5

uint8

Output Calibrated Reflectivity and Near Infrared Photons only in the following order: Calibrated Reflectivity, Near Infrared Photons

AllAttr

6

uint8

Output Calibrated Reflectivity and Near Infrared Photons only in the following order: Calibrated Reflectivity, Near Infrared Photons