Charles K. Gary

Scannerless terrain mapper

NASA-Ames Research Center, in collaboration with Sandia National Laboratories, is developing a scannerless terrain mapper (STM) for autonomous vehicle guidance through the use of virtual reality. The STM sensor is based on an innovative imaging optical radar technology that is being developed by Sandia National Laboratories. The sensor uses active flood- light scene illumination and an image intensified CCD camera receiver to rapidly produce and record very high quality range imagery of observed scenes. The STM is an all solid- state device (containing no moving parts) and offers significant size, performance, reliability, simplicity, and affordability advantages over other types of 3-D sensor technologies, such as scanned laser radar, stereo vision, and structured lighting. The sensor is based on low cost, commercially available hardware, and is very well suited for affordable application to a wide variety of military and commercial uses, including: munition guidance, target recognition, robotic vision, automated inspection, driver enhanced vision, collision avoidance, site security and monitoring, and facility surveying. This paper reviews the sensor technology, discusses NASAs terrain mapping applications, and presents results from the initial testing of the sensor at NASAs planetary landscape simulator.

Propagation of a Gaussian beam in a bacteriorhodopsin film

Gaussian-beam propagation in the bio-optical material bacteriorhodopsin is studied with the consideration of the material’s intensity-dependent absorption and refractive-index modulation. The beam-focusing size, focusing position, intensity change in the material, and the dependence of these factors on the incident-beam parameters are simulated.

Bit-error-rate issues for holographic data storage in bacteriorhodopsin films

Photochromic films made from bacteriorhodopsin (BR) possess many desirable characteristics for a candidate holographic optical data storage medium. These properties include optical erasability, high spatial resolution, adequate diffraction efficiency, flexible film formats, durability, an optimal recording/readout wavelength of about 680 - 690 nm, and potentially inexpensive cost. In this paper, we experimentally study the raw bit-error-rate (BER) achievable with BR films made from the genetic variant known as D85N. Experimental data is collected for digital bit patterns fabricated as chrome-on- glass masks, at two different spatial resolutions. The results show that films fabricated from D85N have good potential for use in holographic data storage systems, but that further effort must be devoted to the film fabrication process in order to minimize optical nonuniformity and scattering losses.

Gaussian beam propagation in a bacteriorhodopsin film

Gaussian-beam propagation in the bio-optical material bacteriorhodopsin is studied with the consideration of the materials intensity-dependent absorption and refractive index modulation. The beam focusing size, focusing position and their dependence on the incident beam parameters are simulated.

Perspectives on the Application of Optical Matrix Processors

Researchers have proposed a great number of optical matrix processing architectures and devices, each having significant advantages and disadvantages. However, no general metrics have been established to compare processors, and there has been little work to implement optical matrix processors for specific applications. In this article, we examine the range of proposed optical matrix processors both to determine the most promising classes of applications and, by establishing performance criteria, to select the best architectures and algorithms for these applications. This examination concludes that the greatest current potential is for analog optical matrix-vector processors to analyze slowly varying or invariant systems with high data throughput rates.

Space structure vibration control using an optical matrix processor

Large, flexible space platforms, such as the proposed Space Station Freedom and Earth Observing System, may experience vibrations caused by astronauts, motorized instruments, or cooling systems which disturb sensitive pointing operations elsewhere on the platform. Linear control systems can be used to dampen these vibrations. In this paper, we discuss the application of optically implemented linear control algorithms to a truss structure model as NASAs Ames Research Center. We describe the system architecture and discuss the effect of reduced accuracy in linear control systems due to analog computation.