Herein are discussed five straightforward field tests that are appropriate for evaluation of the performance of focal plane array (FPA) based ladar systems capable of generating high-resolution 3D imagery. The tests assess system level performance using traditional imaging targets and ladar specific targets. In addition, the tests allow comparisons to be made between the predicted performance of a ladar system and the actual performance. Analysis of actual field test ladar data is included based on appropriateness and availability of data. In the first test, range resolution is examined when the target is obscured by camouflage; the intent is to provide two pulse returns within the same instantaneous field of view (IFOV) and determine the source of the range report from different pixels within the range image with the emphasis on determining performance based on the pulse detection approach that is implemented. The second series of tests evaluates the lateral and range resolution of the FPA using standard modulation transfer function (MTF) and statistical approaches. The third test (Sect. 3.4) involves a moving target to introduce a dynamic version of the previous spatial frequency dependent tests. The fourth test (Sect. 3.5) assesses the system range performance as a function of received signal, essentially determining the performance of the system as signal-to-noise ratio (SNR) is varied. The fifth test (Sect. 3.6) assesses the uniformity of the range resolution and range accuracy of the FPA.
The recent development of optical phased arrays (OPAs) enables practical, electronically programmable, control of laser beams for laser radar and other advanced optical sensors. OPAs are the direct analog of microwave phased array antennas; they are electronically programmable optical elements that control the phase distribution on an optical aperture in order to control beam direction and shape. Operating principles and construction of OPAs are briefly described and current and potential performance capabilities are summarized. An OPA supports spatial-domain beam control such as agile or continuous scanning patterns, adaptive electronic focus control, and far-field beam shape control, as well as the generation of multiple beams from a single input beam (pattern generation, or fanout). OPAs also support time-domain beam control, including precision time delay or positioning of short pulses, pulse compression and expansion, and the generation of dense pulse bursts from a single pulse. All of these functions are software controllable, which enables mission-flexible and mission-adaptive optical systems, including so-called 'smart' optical systems with autonomous alignment and calibration capabilities. These and other electronically programmable capabilities are discussed. As a concrete example of an advanced sensor enabled by the OPA, the potential for an adaptable-format, high-resolution, multi-beam laser radar with no moving parts is discussed.
Conference Committee Involvement (4)
Laser Radar Technology and Applications XIV
15 April 2009 | Orlando, Florida, United States
Laser Radar Technology and Applications XIII
19 March 2008 | Orlando, Florida, United States
Laser Radar Technology and Applications XII
11 April 2007 | Orlando, Florida, United States
Laser Radar Technology and Applications XI
19 April 2006 | Orlando (Kissimmee), Florida, United States