1. A flash ladar to sense objects in the path of a vehicle, said flash ladar comprising: a pulsed laser transmitter with an optical axis and a pulsed laser output and a diffusing optic for illuminating a scene in a field of view with a pattern of light intensity, receive optics boresighted along said optical axis adapted to collect and condition an optical pulse comprised of pulsed light reflected from said scene in the field of view, an optical receiver with a light detecting focal plane array comprised of a plurality of light detecting elements, said light detecting focal plane array disposed to intercept said collected and conditioned optical pulse from said receive optics, and said light detecting focal plane array connected to a readout integrated circuit, said readout integrated circuit having a corresponding plurality of unit cell electrical circuits, and each light detecting element in said light detecting focal plane array intercepting a portion of said optical pulse, and each light detecting element of said light detecting focal plane array producing a pixel electrical pulse in response to said optical pulse, said pixel electrical pulse corresponding to a pixel of a three dimensional image, a system controller adapted to activate said pulsed laser transmitter to provide said pulsed laser output and to control said optical receiver, an optical pickup positioned to intercept an optical sample of the pulsed laser output, and guide said optical sample to a reference detector, said reference detector adapted to provide a zero time reference electrical output to each unit cell of said readout integrated circuit, each light detecting element of said focal plane array connected to an input of a unit cell electrical circuit of said readout integrated circuit, a timing clock connected to a counter in each unit cell electrical circuit, and each unit cell electrical circuit having an amplifier and a threshold detector, said threshold detector adapted to produce a logic signal indicating the arrival of the pixel electrical pulse, said counter started counting by the zero time reference electrical output, and said counter accumulating the number of cycles of said timing clock, and said counter stopped counting by said logic signal, and said readout integrated circuit adapted to output said number of cycles for each of said counters.