Calibrated Reflectivity

Calibrated reflectivity is an 8-bit lidar packet field. The field scales measured signal photons by range and sensor sensitivity to estimate target reflectivity.

Factory-calibrated sensors report higher reflectivity accuracy. Sensors without factory reflectivity calibration use default calibration values and can have lower accuracy.

Note: Rev7 sensors require Firmware v3.0.0 or later. Rev8 sensors (including OS1-MAX) require Firmware v4.0 or later. All Rev8 sensors are factory calibrated, so reflectivity.valid is true. reflectivity.valid is false only on some older Rev7 sensors. Those sensors were calibrated on Firmware v3.1 or earlier. They were then updated to Firmware v3.2 or later.

Read GET /api/v1/sensor/metadata/calibration_status for the reflectivity calibration status:

{
  "reflectivity": {
    "valid": "true if factory calibrated for better accuracy, false if using default values (older Rev7 sensors only)",
    "timestamp": "Date calibration was performed"
  }
}

Contact support@ouster.io with questions about hardware eligibility for calibrated reflectivity.

Reflectivity Calibration Improvements

Reflectivity calibration version 2 (V2) combines a calibration improvement with a firmware improvement in firmware v3.2 and later. It improves calibrated reflectivity performance across all ranges, with even greater improvement in the near range due to an updated calibration process. Only sensors factory-calibrated on firmware v3.2 or later have V2 support.

The default behavior uses the latest available reflectivity calibration version. If directed by Ouster Support, the calibration version can be selected with GET /api/v1/sensor/config/{param} and PUT /api/v1/sensor/config/{param} using the parameter manufacturing_calibration/reflectivity_version.

Valid values are:

• LATEST - use the latest available calibration version. This is the default and recommended setting.
• V2 - use reflectivity calibration version 2.
• V1 - use reflectivity calibration version 1.
• V0 - use reflectivity calibration version 0.

The selected value restricts the maximum calibration version used. For example, if V2 is selected but the sensor only has V1 and V0 calibration data available, V1 is used instead.

Warning: Changing manufacturing_calibration/reflectivity_version can affect reflectivity measurements and should only be done under guidance from Ouster Support.

Reflectivity Data Mapping

In firmware v3.2 and later, value 0 means no valid return. Values 1–100 map linearly to 1–100% Lambertian reflectivity.

Values 101–255 use log₂ mapping with linear interpolation for retroreflective targets. The value 255 corresponds to a retroreflector 864× stronger than a 100% Lambertian target.

Note: The table image lists representation 0–100 as a linear range. Representation 0 is reserved (no valid return). Valid Lambertian values start at 1.