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High Peak Power VCSELs in Short Range LIDAR Applications
1Department of Physics, Astronomy, and Geophysics, Connecticut College, New London, Connecticut 06320, 2Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420 A technique for short-range LIDAR that monitors high-peak-power pulses rather than uniform square pulses is demonstrated using a commercially available Optek OPV310 VCSEL with a 10μm aperture operating at a wavelength of 850nm for applications in LIDAR-based active defense systems. Using 10ns pulses at a 0.1% duty cycle and 60mW of peak power, a target one meter away exhibiting Lambertian reflectance was detected with a 3:1 minimum signal-to-noise ratio in a narrow-field LIDAR setup using a 28dB amplifier. At 0.75m, using the same target and no signal amplification, a 2:1 minimum signal to noise ratio was achieved in a wide-field setup. These results establish the viability of commercially available low power VCSEL devices for LIDAR. LIDAR, VCSELs 1. Geske, J., C. Wang, M. MacDougal, R. Stahl, D. Follman, H. Garrett, T. Meyrath, D. Snyder, E. Golden, J. Wagener, and J. Foley. “High power VCSELs for miniature optical sensors,” Proc. of SPIE 7615 (2010): 76150E-1–11, doi: 10.117/12.847184. Spacecraft Approaching Technique
Harriet L Wilkes Honors College of Florida Atlantic University, Department of Physics, Jupiter, FL Using already established equations of motion for particles under a gravitational force, we analyze the motion of two spacecrafts in the same circular orbit approaching each other if one of the craft were to speed up or slow down. The purpose of this paper is to analyze and develop equations of motion for the transfer of spacecrafts from circular orbits to elliptical orbits with the intention of spacecraft approach. We can come up with a table of velocities that allow for a number of safe approaches for the spacecraft to take. We found that projecting a safe approach requires that we know the new speed of the transfer spacecraft, the desired change in distance between the two spacecrafts, and the magnitude of the radius vector of the perigee for the elliptical transfer. Spacecraft, Particle Motion, Approach 1. Beer, Ferdinand P., and E. Russell Johnston. “Kinetics of Particles: Energy and Momentum.” Vector mechanics for engineers: dynamics. 5th ed. New York: McGraw-Hill, 1988. 729-826. Print |
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