Abstract: 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(m2, p*)?(p*?1)/2, wherein dJs are modulation values; calculating a list of nominal pulse timings T, as T=m×ceil(TPRI/?j), where ?j is a predetermined modulation resolution, and TPRI is the reciprocal of the PRF; and generating the cyclically optimal PPM waveform from the pulse timings t0.

Abstract: A transmitter for communication-less bistatic ranging includes a photon emitter configured to emit a plurality of photons at particular times in a pointing direction, and a processor configured to identify a particular sub-code of a plurality of sub-codes based on a dynamic state of the transmitter, each one of the plurality of sub-codes including a portion of a long optimal ranging code, generate a plurality of encoded pulse timings by dithering pulse timings from a nominal repetition frequency based on the particular sub-code, and control the photon emitter to emit the plurality of photons at the plurality of encoded pulse timings.

Abstract: A lidar for generating long PPM waveforms includes: receiving an initial PPM code element and a desired maximum sidelobe height; b) generating a two-column lookup table; c) selecting a candidate modulation level from a pool of available elements; d) identifying the differences between the selected candidate modulation value and each of the code values in the initial PPM code and incrementing corresponding values in the lookup table; e) comparing the values of the lookup table against the desired maximum sidelobe height; f) when a value exceeds the desired maximum sidelobe height, discarding the candidate modulation level, decrementing the corresponding values in the lookup table and repeating steps c to g; g) otherwise, appending the candidate modulation level to the end of the initial PPM code to update the initial code, and repeating steps c to e N times to generate a PPM waveform of length N.

Abstract: Lidar and method for generating repeatable PPM waveforms to determine a range to a target include: a processor for a) creating a modulation pool, based on a maximum nominal PRF and a specified final PPM code length of N; b) obtaining a seed code; c) eliminating bad modulation levels from the modulation pool to generate a good modulation pool, d) selecting a modulation level from the good modulation pool; e) concatenating the selected modulation level to the seed code to generate an i-element modulation sequence; f) repeating steps c to e N times to generate an N-element modulation sequence; g) selecting a PRF less than the maximum nominal PRF; and h) generating a repeatable PPM waveform by applying the N-element modulation sequence to the selected PRF.

Abstract: A laser detection and ranging system and method for operating thereof. In some embodiments, the method includes: transmitting a plurality of laser pulses, each at a respective one of a plurality of pulse transmission times; detecting a plurality of return pulses, each at a respective one of a plurality of return pulse times; and estimating a range or a range rate of a target based on the pulse transmission times and the return pulse times. Each of the pulse transmission times may be offset from a corresponding nominal pulse transmission time by a respective pulse position modulation offset, the nominal pulse transmission times being uniformly spaced with a period corresponding to a pulse repetition frequency, the pulse repetition frequency being greater than 500 kHz.

Abstract: A method for operating a laser detection and ranging system. In some embodiments, the method includes transmitting a plurality of laser pulses, each at a respective one of a plurality of pulse transmission times; detecting a plurality of return pulses, each at a respective one of a plurality of return pulse times; forming a first time difference, the first time difference being the difference between a first return pulse time of the plurality of return pulse times and a first pulse transmission time of the plurality of pulse transmission times; and incrementing a first element of a first array, the first element of the first array having an index based on the first time difference.