A solid-state imaging device comprises a first pixel group includes a first photoelectric conversion unit that converts into electric charges reflection light pulses from an object irradiated with an irradiation light pulse, a first electric charge accumulation unit accumulating the electric charges in synchrony with turning on the irradiation light pulses, and a first reset unit resetting the electric charges; and a second pixel group includes a second photoelectric conversion unit that converts the reflection light into electric charges, a second electric charge accumulation unit that accumulates the electric charges synchronously with a switching the irradiation light pulses from on to off, and a second reset unit that releases a reset of the electric charges converted by the second photoelectric conversion unit.

A solid-state imaging device comprises a first pixel group includes a first photoelectric conversion unit that converts into electric charges reflection light pulses from an object irradiated with an irradiation light pulse, a first electric charge accumulation unit accumulating the electric charges in synchrony with turning on the irradiation light pulses, and a first reset unit resetting the electric charges; and a second pixel group includes a second photoelectric conversion unit that converts the reflection light into electric charges, a second electric charge accumulation unit that accumulates the electric charges synchronously with a switching the irradiation light pulses from on to off, and a second reset unit that releases a reset of the electric charges converted by the second photoelectric conversion unit.

A position reference sensor (100) has a light source (120), a detector (160) and a processor (170). The light source (120) is configured to emit light having a first component and a second component. The detector (160) is configured to detect reflected light. The processor (170) is configured to determine a distance between the position reference sensor (100) and a target based on the emitted light and the detected reflected light. The processor (170) is also configured to determine that the target is a selective retroreflector (140) based on the intensity of the first component of the light in the detected reflected light and the intensity of the second component of the light in the detected reflected light.

A position reference sensor (100) has a light source (120), a detector (160) and a processor (170). The light source (120) is configured to emit light having a first component and a second component. The detector (160) is configured to detect reflected light. The processor (170) is configured to determine a distance between the position reference sensor (100) and a target based on the emitted light and the detected reflected light. The processor (170) is also configured to determine that the target is a selective retroreflector (140) based on the intensity of the first component of the light in the detected reflected light and the intensity of the second component of the light in the detected reflected light.

A system and method for enhanced velocity resolution and signal to noise ratio in optical phase-encoded range detection includes receiving an electrical signal generated by mixing a first optical signal and a second optical signal, wherein the first optical signal is generated by modulating an optical signal, wherein and the second optical signal is received in response to transmitting the first optical signal toward an object, and determining a Doppler frequency shift of the second optical signal, and generating a corrected electrical signal by adjusting the electrical signal based on the Doppler frequency shift, and determining a range to the object based on a cross correlation of the corrected electrical signal with a radio frequency (RF) signal that is associated with the first optical signal.

A system and method for enhanced velocity resolution and signal to noise ratio in optical phase-encoded range detection includes receiving an electrical signal generated by mixing a first optical signal and a second optical signal, wherein the first optical signal is generated by modulating an optical signal, wherein and the second optical signal is received in response to transmitting the first optical signal toward an object, and determining a Doppler frequency shift of the second optical signal, and generating a corrected electrical signal by adjusting the electrical signal based on the Doppler frequency shift, and determining a range to the object based on a cross correlation of the corrected electrical signal with a radio frequency (RF) signal that is associated with the first optical signal.

A lidar for generating a cyclically optimal Pulse Position Modulated (PPM) waveform includes: a memory for storing a list of prime numbers; a processor for obtaining a list of prime numbers up to a predetermined maximum code length; selecting a largest prime number p* that is less than or equal to a ratio of a timing system bandwidth to the predetermined pulse repetition frequency (PRF), from the list of the prime numbers; constructing a list of pulse indices, m=0: p*−1 for the cyclically optimal PPM waveform; calculating a list of pulse modulations, dJs=mod(m.sup.2, p*)−(p*−1)/2, wherein dJs are modulation values; calculating a list of nominal pulse timings T, as T=m×ceil(T.sub.PRI/Δj), where Δj is a predetermined modulation resolution, and T.sub.PRI is the reciprocal of the PRF; calculating pulse timings t.sup.0 of the cyclically optimal PPM waveform as t.sup.0=Δj×(T+dJs); and generating the cyclically optimal PPM waveform from the pulse timings t.sup.0.

Disclosed are a distance image acquisition apparatus and a distance image acquisition method capable of achieving high distance measurement accuracy and omitting wasteful imaging or calculation. The distance image acquisition apparatus (10) includes a distance image sensor (14), a drive mode setting unit (20A), a distance image generation unit (20B), a pulse light emission unit (22), and an exposure control unit (24). The exposure control unit (24) controls emission and non-emission of pulse light emitted from the pulse light emission unit (22) according to a drive mode set by the drive mode setting unit (20A), and controls exposure in the distance image sensor (14). The distance image generation unit (20B) performs calculation processing of a sensor output acquired from the distance image sensor (14) according to the drive mode set by the drive mode setting unit (20A) to generate a distance image corresponding to a distance of a subject.

An electro-optical distance meter comprises a light source for emitting a distance measuring light, a distance measuring optical system for leading a distance measuring light to a photodetector, an internal reference optical system for leading a part of the distance measuring light as an internal reference light to the photodetector, and an arithmetic processing unit for performing a distance measurement based on light receiving results of the distance measuring light and the internal reference light, wherein the internal reference optical system comprises a condenser lens, a scattering plate for scattering the internal reference light and for forming a secondary light source, and an optical fiber for leading the internal reference light to the photodetector and the internal reference optical system is constituted in such a manner that a light component of the internal reference light emitted from an arbitrary point within a whole surface of the secondary light source enters the optical fiber.

An optical device for the contactless measurement of a liquid level contained in a storage device by an optical signal, the optical device including an optical unit fixedly positioned above the storage device and an electronic control unit capable of emitting an optical signal, dissociated from the optical unit and positioned at a distance from the optical unit. The optical unit includes a single channel for the emission and the reception of the optical signal. The optical unit is connected to the electronic control unit through an optical fibre capable of transmitting the optical signal emitted by the electronic control unit and an optical signal reflected by the liquid. The optical fibre has first and second optical cores that juxtapose each other such that at least a part of the optical signal emitted in the first optical core of the optical fibre is backscattered in the second optical core.