초록 ▼

A video imaging apparatus for scanning an area during relative motion in a direction defining a track axis has at least two linear sensors each comprised of at least one array of charge coupled devices. The sensors are oriented substantially perpendicular to the track axis thereby defining a cross-t

A video imaging apparatus for scanning an area during relative motion in a direction defining a track axis has at least two linear sensors each comprised of at least one array of charge coupled devices. The sensors are oriented substantially perpendicular to the track axis thereby defining a cross-track axis. The arrays are further fixed relative to each other and oriented for simultaneously scanning the same area. A master clock signal is used to readout the data produced by the first sensor. A phase-locked loop produces a slaved, pliant, clock signal for reading the data out of the second sensor. By varying the phase of the slaved clock signal relative to the master clock signal, mechanical offset between the two sensors is compensated. By varying the average frequency of the slaved clock signal relative to the master clock signal, scale differences between the two sensors are compensated. By cyclically varying the instantaneous clock frequency along the cross-track axis of the salved clock signal relative to the master clock signal, lens distortion is compensated. Thus, by utilizing the phase-locked loop to control plural characteristics of the slaved clock signal, the retreival of data from the sensors may be more accurately coordinated and the necessity of costly, complex, off-line post-processing avoided.

대표청구항 ▼

An improved multisensor video imaging apparatus of the type using plural linear arrays of elemental electrical transducers nominally fixed with respect to one another with each array\s longitudinal axis functionally oriented in a “cross track”direction substantially perpendicular to a “track axis”al

An improved multisensor video imaging apparatus of the type using plural linear arrays of elemental electrical transducers nominally fixed with respect to one another with each array\s longitudinal axis functionally oriented in a “cross track”direction substantially perpendicular to a “track axis”along which the arrays are simultaneously moved relative to a scanned area so as to successively scan, in nominal synchronism, corresponding common incremental portions of that area, said improvement comprising: first and second linear arrays of elemental electrical transducers, each elemental transducer being capable of generating an electrical signal representative of its incident illumination and each array being capable of sampling and reading out a series of respectively corresponding electrical signals in response to applied clock signals; master clock means for providing master clock signals and first arrayed driver means connected thereto and to said first array to control the sampling and reading of electrical signals output from said first array of electrical transducers; and a controlled oscillator circuit means for providing pliant clock signals and second array driver means connected thereto and to said second array to control the sampling and reading of electrical signals output from said second array of electrical transducers; said controlled oscillator circuit means being connected to said master clock means for nominal control by said master clock signal but also having at least one supplemental control signal input for controllably varying the timing of said pliant clock signals with respect to said master clock signals so as to controllably maintain desired synchronism with respect to said cross-track axis between the sampling and reading of electrical signals output from said first and second arrays of electrical transducers.