Browsing Space, Telecommunication, Astronomy, & Radiation Lab by Author "Cahoy, K. L."

Now showing items 1-7 of 7

    • Active Polarimetric Measurements for Identification and Characterization of Space Debris 

      Pasqual, M. C.; Cahoy, K. L. (Institute of Electrical and Electronics Engineers, 2017-06)
      A bench-top polarimeter ( λ = 1064 nm) is used to measure the polarimetric Bidirectional Reflectance Distribution Function (BRDF) of several common spacecraft materials in both bistatic and monostatic geometries. The Mueller ...

    • Assessment of Radiometer Calibration With GPS Radio Occultation for the MiRaTA CubeSat Mission 

      Marinan, A. D.; Cahoy, K. L.; Bishop, R. L.; Lui, S. S.; Bardeen, J. R.; e.a. (Institute of Electrical and Electronics Engineers, 2016-12)
      The microwave radiometer technology acceleration (MiRaTA) is a 3U CubeSat mission sponsored by the NASA Earth Science Technology Office. The science payload on MiRaTA consists of a triband microwave radiometer and global ...

    • First results on a new PIAA coronagraph testbed at NASA Ames 

      Belikov, R.; Pluzhnik, E.; Connelley, M. S.; Witteborn, F. C.; Lynch, D. H.; e.a. (SPIE - The International Society for Optical Engineering, 2009-01-01)
      Direct imaging of extrasolar planets, and Earth-like planets in particular, is an exciting but difficult problem requiring a telescope imaging system with 1010 contrast at separations of 100 mas and less. Furthermore, the ...

    • Implementation and validation of a CubeSat laser transmitter 

      Kingsbury, R. W.; Caplan, D. O.; Cahoy, K. L. (SPIE, 2016)
      The paper presents implementation and validation results for a CubeSat-scale laser transmitter. The master oscillator power amplifier (MOPA) design produces a 1550 nm, 200mW average power optical signal through the use of ...

    • Radiometer Calibration Using Colocated GPS Radio Occultation Measurements 

      Cahoy, K. L.; Blackwell, W. J.; Bishop, R.; Cohen, B.; Crail, C.; e.a. (Institute of Electrical and Electronics Engineers, 2014-10)
      We present a new high-fidelity method of calibrating a cross-track scanning microwave radiometer using Global Positioning System (GPS) radio occultation (GPSRO) measurements. The radiometer and GPSRO receiver periodically ...

    • Space weather radiation effects on geostationary satellite solid-state power amplifiers 

      Lohmeyer, W. Q.; Cahoy, K. L. (American Geophysical Union, 2013-08)
      In order to understand and mitigate the effects of space weather on the performance of geostationary (GEO) communications satellites, we analyze 16 years of archived telemetry data from Inmarsat, the UK-based telecommunications ...

    • Wavefront control in space with MEMS deformable mirrors for exoplanet direct imaging 

      Cahoy, K. L.; Marinan, A. D.; Novak, B.; Kerr, C.; Nguyen, T.; e.a. (SPIE-SOC Photo-Optical Instrumentation Engineers, 2013-10)
      To meet the high contrast requirement of 1 x 10(-10) to image an Earth-like planet around a sun-like star, space telescopes equipped with coronagraphs require wavefront control systems. Deformable mirrors (DMs) are a key ...