Remotely controlled or tele-operated robots are playing an increasing role in military, law enforcement and industrial operations. In order for a remote operator to rapidly and efficiently control an unmanned vehicle (UV), the operator must be able to view the robot surroundings as if they were actually present at the location of the robot. The current limiting factor to providing this level of presence is the visual display utilized by the operator, which for portability, size and weight is optimally a head-worn display (HWD). When in addition local situational awareness of the operator must be maximized, the HWD should be of the optical see-through (OST) type. The ideal requirements for the OST-HWD for UV-control include: a large binocular display field-of-view, methods to prevent development of cyber sickness and appropriate brightness for use in all relevant lighting conditions. Limitations of current OST-HWDs are reviewed, and a new type of OST-HWD is described, which offers significant advantages for remote control of UVs. An initial prototype has been constructed, and its performance is quantified. The prototype provides a large display FOV, large eye box, and high brightness. It uses low-cost COTS components. When the operator of the unmanned vehicle must use their hands for other purposes, a hands-free control interface for both the display and robot is highly desirable. An implementation of a hands-free control interface based on eye tracking is described.
A new type of spectacle lens was developed incorporating a thin layer of a novel polymer with a light-programmable
refractive index. The refractive index change can be used to change the optical power of the lens. One of the
applications of this new lens is the correction of high-order aberrations of the human eye. A feasibility study was
conducted to determine whether such wavefront-guided high-order correcting spectacle lenses can be 1) accurately
manufactured, and 2) improve vision of human subjects. The ocular wavefront of 30 subjects was measured with a Z-ViewTM diffractive aberrometer. A vision correcting high-order zone canceling the subjects' ocular wavefront was
"programmed" directly into pairs of wavefront-guided spectacle lenses (WFGSL). The lenses could be successfully
manufactured to an average Zernike rms accuracy of 81% (range 70% to 90%). Comparison was made against identical
spectacles without the high-order zone. Double-masked vision tests included high and low-contrast visual acuity, and
contrast sensitivity. The subject was allowed only a few minutes of adaptation time to the spectacles. While some
experienced a dramatic improvement in vision, this was not observed for all subjects, in particular for subjects with
small amounts of high-order aberrations. We speculate that more consistent vision improvement can be achieved by 1)
determining a subject's candidacy for WFGSL based on the subject's ocular aberrations, 2) correcting only selected
aberrations, 3) manufacture with higher purity and accuracy, and 4) lengthening the adaptation period before testing
each lens.
GLINT (Geo Light Imaging National Testbed) is a program to image geo-synchronous satellites using Fourier telescopy. The design of the GLINT system requires knowledge of the reflectance properties of the satellites in certain specific wavelength ranges. Calibrated measurements of satellite brightness due to solar illumination can be made with a telescope. This report details such measurements and the data processing necessary to yield curves of normalized satellite return versus phase angle in given wavelength ranges. These measurements can be used to check the accuracy of satellite reflectivity models.
Several electron beam activated diamond switches have been constructed and operated. In an initial set of experiments the electron source consisted of a LaB6 photocathode illuminated by approximately 15 nanosecond pulses of 248 nm light from a KrF laser. The photocathode could be biased at voltage of 10 - 80 kV. The type IIa diamond wafer was 12 microns thick with top and bottom electrodes consisting of Ti/Pt/Au sputtered metallizations (unannealed). Limited by surface flashover across a 12 micron broken edge of the diamond wafer, pulses with a peak power at the kilowatt level into 50 ohms were generated. The output pulse duration was set by the electron beam duration or the round trip time in the charged transmission line, whichever was shorter. Measurement of the output pulse rise time was limited by the diagnostic oscilloscope resolution but was less than one nanosecond. It was observed that the output pulse amplitude reached the expected value only when the bombarding electron beam voltage was sufficiently large that carrier pairs were generated throughout the thickness of the diamond sample.
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