Sensor Performance by Operating Configuration | Ouster Sensor Docs

Sensor performance varies by lidar mode and signal multiplier. The tables below show estimated range multipliers relative to the datasheet baseline for each operating configuration.

Estimated Range Multiplier

Signal multipliers above 1x increase range, with the exact gain depending on lidar mode.

OS0 and OS1

For OS0, OSDome, and OS1 sensors, the baseline is 1024x10 mode.

Frame Rate / Horizontal Resolution `512` Mode

Signal Multiplier	0.25x	0.5x	1x	2x	3x
10 Hz	0.84	1	1.19	1.41	1.57
20 Hz	0.71	0.84	1	1.19	1.32

Frame Rate / Horizontal Resolution `1024` Mode

Signal Multiplier	0.25x	0.5x	1x	2x	3x
10 Hz	0.71	0.84	1	1.19	1.32
20 Hz	0.59	0.71	0.84	1	1.11

Frame Rate / Horizontal Resolution `2048` Mode

Signal Multiplier	0.25x	0.5x	1x	2x	3x
10 Hz	0.59	0.71	0.84	1	1.11
20 Hz	NA	NA	NA	NA	NA

Note: These values are estimates for guidance only. Guaranteed specifications are those listed in the datasheet for each mode.

OS2

For OS2 sensors, the baseline is 2048x10 mode.

Frame Rate	512 / 1x	512 / 2x	512 / 3x	1024 / 1x	1024 / 2x	1024 / 3x	2048 / 1x	2048 / 2x	2048 / 3x
10 Hz	1.41	1.68	1.86	1.19	1.41	1.57	1.00	1.19	1.32
20 Hz	1.19	1.41	1.57	1.00	1.19	1.32	NA	NA	NA

Note: These values are estimates for guidance only. Guaranteed specifications are those listed in the datasheet for each mode.

Maximal Representable Range

Maximum representable range varies by signal multiplier. The table below lists values for each sensor type.

Signal Multiplier Value	OS0	OS1	OS2
0.25x	491 m	491 m	491 m
0.5x	491 m	491 m	491 m
1x	270 m	270 m	465 m
2x	135 m	135 m	232 m
3x	90 m	90 m	155 m

Returns beyond the maximum representable range may alias. Use these modes only in environments where no targets exist at that range.

Shot Limiting

Shot limiting is an automatic thermal protection mechanism. At high temperatures, the sensor progressively reduces laser duty cycle to lower thermal load. Multiple levels of shot limiting are described in the table below.

The sensor uses three states to manage elevated temperatures:

NORMAL (Status 0x00)
SHOT_LIMITING_IMMINENT (Status 0x01)
SHOT_LIMITING (Status 0x02 and greater)

In NORMAL state, the sensor meets all datasheet range and precision specifications. When temperature rises above a threshold, the sensor enters SHOT_LIMITING_IMMINENT and issues alert 0x0100000E, signaling that shot limiting will begin in 30 s. If the temperature remains elevated after 30 s, the sensor issues alert 0x0100000F and enters SHOT_LIMITING.

In SHOT_LIMITING, the sensor reduces laser power to lower thermal load. Range and precision may degrade by up to 30%. Shot limiting intensifies progressively if the temperature stays elevated. When maximum shot limiting is reached, the sensor issues alert 0x0100003A.

If the sensor cools while in SHOT_LIMITING_IMMINENT or SHOT_LIMITING, it returns to NORMAL automatically.

A separate state machine manages thermal shutdown. When the sensor hits its maximum operating temperature, it enters SHUTDOWN_IMMINENT and raises an OVERTEMP alert. If the temperature remains elevated for 30 s, the sensor shuts down and issues alert 0x0100006B.

Note: Please refer to the Hardware User Manual to learn more about the maximum thermal performance.

Information regarding the shot limiting status is presented as part of the lidar data packet in the configurable data packet format. Shot limiting status is part of the packet header when config parameter udp_profile_lidar is set to one of the following values.

RNG19_RFL8_SIG16_NIR16
RNG15_RFL8_NIR8
RNG19_RFL8_SIG16_NIR16_DUAL

The following flags are present in configurable data packet header:

Shot limiting status [4 bit unsigned int] - Indicates the shot limiting status of the sensor. Different codes indicates whether the sensor is in Normal Operation or in Shot limiting.

Shutdown Status [4 bit unsigned int] - Indicates whether thermal shutdown is imminent. This can be due to shot limiting being saturated, or due to any other over temperature conditions and depending upon the situation the appropriate alert is generated. When thermal shutdown is imminent, this flag will be set to 1 and the Thermal Shutdown Countdown field will be set to 30 seconds.

Shot limiting Countdown [8 bit unsigned int] - Countdown from 30 seconds to indicate when shot limiting is imminent. When the condition for entering shot limiting is met, the shot limiting status bit is set to 0x01 and the alert 0x0100000E takes effect. At this point the shot limiting counter will be set to 30 seconds and a countdown to initiate shot limiting will start.

Shutdown Countdown [8 bit unsigned int] - Countdown from 30 seconds to indicate that thermal shutdown is imminent. When a thermal shutdown is completed, the alert 0x0100006B will take effect and the sensor will automatically go to the ERROR state and stop outputting data.

The following table describes the codes in the shot limiting status flags, and what mode it corresponds to:

Shot Limiting Status	Description
`0x00`	Normal Operation. When the sensor is not in shot limiting, the shot limiting status flag will be set to 0x00, and shot limiting countdown will be set to 0x00.
`0x01`	When the condition for entering Shot limiting is met, we set the Shot Limiting Status bit 0x01 and the alert 0x0100000E is in effect, informing that shot limiting is imminent.
`0x02`	In this mode, we reduce the % of nominal laser duty cycle by 0-10% from NORMAL OPERATION. There will be an approximate reduction in the sensor max range by 3%.
`0x03`	In this mode, we reduce the % of nominal laser duty cycle by 10-20% from NORMAL OPERATION. There will be an approximate reduction in the sensor max range by 6%.
`0x04`	In this mode, we reduce the % of nominal laser duty cycle by 20-30% from NORMAL OPERATION. There will be an approximate reduction in the sensor max range by 9%.
`0x05`	In this mode, we reduce the % of nominal laser duty cycle by 30-40% from NORMAL OPERATION. There will be an approximate reduction in the sensor max range by 12%.
`0x06`	In this mode, we reduce the % of nominal laser duty cycle by 40-50% from NORMAL OPERATION. There will be an approximate reduction in the sensor max range by 16%. For OS2 and OSDome sensors this mode is when shot limiting is saturated and alert 0x0100003A is in effect. There will be an approximate reduction in the sensor max range by 21%.
`0x07`	In this mode, we reduce the % of nominal laser duty cycle by 50-60% from NORMAL OPERATION. There will be an approximate reduction in the sensor max range by 21%.
`0x08`	In this mode, we reduce the % of nominal laser duty cycle by 60-70% from NORMAL OPERATION. There will be an approximate reduction in the sensor max range by 25%.
`0x09`	In this mode, we reduce the % of nominal laser duty cycle by 70-75% from NORMAL OPERATION. There will be an approximate reduction in the sensor max range by 27%. For OS0 and OS1 sensors this mode is when shot limiting is saturated and alert 0x0100003A is in effect. There will be an approximate reduction in the sensor max range by 27%.