Dual-mode lidar system

A lidar system comprising:

• a light source configured to emit a pulse of light;
• a receiver configured to detect at least a portion of the emitted pulse of light scattered by a target located a distance from the lidar system;
• and
• a processor configured to determine the distance from the lidar system to the target based at least in part on a round-trip time of flight for the emitted pulse of light to travel from the lidar system to the target and back to the lidar system;
• wherein if (i) the distance to the target is greater than a particular maximum distance or (ii) at least one of a horizontal scan angle or a vertical scan angle is outside a respective particular range within a field of regard of the lidar system, then the light source is further configured to refrain from emitting a series of pulses of light, otherwise:
• the light source is further configured to emit a series of pulses of light having particular pulse-frequency characteristics;
• the receiver is further configured to detect at least a portion of the series of emitted pulses of light scattered by the target;
• and
• the lidar system further comprises a comparison module configured to compare the pulse-frequency characteristics of the series of emitted pulses of light with corresponding pulse-frequency characteristics of the detected series of scattered pulses of light to determine a velocity of the target with respect to the lidar system.

A method comprising:

• emitting, by a light source of a lidar system, a series of pulses of light having particular pulse-frequency characteristics;
• detecting, by a receiver of the lidar system, at least a portion of the series of emitted pulses of light scattered by a first target located a first distance from the lidar system;
• determining, by a processor of the lidar system, the first distance from the lidar system to the first target based at least in part on a round-trip time of flight for the series of emitted pulses of light to travel from the lidar system to the first target and back to the lidar system;
• and
• comparing, by a comparison module, the pulse-frequency characteristics of the series of emitted pulses of light with corresponding pulse-frequency characteristics of the detected series of scattered pulses of light to determine a velocity of the first target with respect to the lidar system,
• wherein each of the emitting, the detecting, the determining, and the comparing occurs in a first instance to generate a value of a first pixel, the method further comprising, in a second instance:
• emitting, by the light source, a single pulse of light;
• detecting, by the receiver, at least a portion of the emitted pulse of light scattered by a second target located a second distance from the lidar system;
• and
• determining, by the processor of the lidar system, the second distance from the lidar system to the second target based at least in part on a round-trip time of flight for the emitted pulse of light to travel from the lidar system to the second target and back to the lidar system to generate a value of a second pixel,
• wherein each of the first pixel and the second pixel correspond to respective ranging events of equal duration.

A method comprising:

• emitting, by a light source of a lidar system, a pulse of light;
• detecting, by a receiver of the lidar system, at least a portion of the emitted pulse of light scattered by a target located a distance from the lidar system;
• determining, by a processor of the lidar system, the distance from the lidar system to the target based at least in part on a round-trip time of flight for the emitted pulse of light to travel from the lidar system to the target and back to the lidar system;
• emitting, by the light source, a series of pulses of light having particular pulse-frequency characteristics, wherein the pulse-frequency characteristics of the series of emitted pulses of light comprise (i) an increasing pulse repetition frequency, (ii) a decreasing pulse repetition frequency, or (iii) a pseudo-random sequence of pulses of light having pseudo-random intervals of time between the pulses;
• detecting, by the receiver, at least a portion of the series of emitted pulses of light scattered by the target;
• and
• comparing, by a comparison module, the pulse-frequency characteristics of the series of emitted pulses of light with corresponding pulse-frequency characteristics of the detected series of scattered pulses of light to determine a velocity of the target with respect to the lidar system.

A method comprising:

• emitting, by a light source of a lidar system, a pulse of light;
• detecting, by a receiver of the lidar system, at least a portion of the emitted pulse of light scattered by a target located a distance from the lidar system;
• determining, by a processor of the lidar system, the distance from the lidar system to the target based at least in part on a round-trip time of flight for the emitted pulse of light to travel from the lidar system to the target and back to the lidar system;
• selecting, by the processor and in view of the determined distance to the target, one or more of:
• (i) a pulse energy of pulses in a series of pulses of light, (ii) a width of pulses in the series of pulses of light, and (iii) a number of pulses to be included in the series of pulses of light;
• emitting, by the light source, the series of pulses of light, the series of emitted pulses of light having particular pulse-frequency characteristics;
• detecting, by the receiver, at least a portion of the series of emitted pulses of light scattered by the target;
• and
• comparing, by a comparison module, the pulse-frequency characteristics of the series of emitted pulses of light with corresponding pulse-frequency characteristics of the detected series of scattered pulses of light to determine a velocity of the target with respect to the lidar system.