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  • 1
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    Small All-Range Lidar for Asteroid and Comet Core Missions (2021)
    Molecular Diversity Preservation International
    Details
    Publication Date: 2021-04-28
    Description: We report the development of a new type of space lidar specifically designed for missions to small planetary bodies for both topographic mapping and support of sample collection or landing. The instrument is designed to have a wide dynamic range with several operation modes for different mission phases. The laser transmitter consists of a fiber laser that is intensity modulated with a return-to-zero pseudo-noise (RZPN) code. The receiver detects the coded pulse-train by correlating the detected signal with the RZPN kernel. Unlike regular pseudo noise (PN) lidars, the RZPN kernel is set to zero outside laser firing windows, which removes most of the background noise over the receiver integration time. This technique enables the use of low peak-power but high pulse-rate lasers, such as fiber lasers, for long-distance ranging without aliasing. The laser power and the internal gain of the detector can both be adjusted to give a wide measurement dynamic range. The laser modulation code pattern can also be reconfigured in orbit to optimize measurements to different measurement environments. The receiver uses a multi-pixel linear mode photon-counting HgCdTe avalanche photodiode (APD) array with near quantum limited sensitivity at near to mid infrared wavelengths where many fiber lasers and diode lasers operate. The instrument is modular and versatile and can be built mostly with components developed by the optical communication industry.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by Molecular Diversity Preservation International
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    PAPER CURRENT
  • 2
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    Development of Low Noise and High Speed SWIR Receivers (2010)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: No abstract available
    Keywords: Optics; Engineering (General); Instrumentation and Photography
    Type: LEGNEW-OLDGSFC-GSFC-LN-1000 , Society of Photo-Instrumentation Engineers (SPIE) Defense, Security and Sensing; Apr 05, 2010 - Apr 09, 2010; Orlando, FL; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 3
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    Comparison of 16-Channel Laser Photoreceivers for Topographic Mapping (2011)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Topographic mapping lidar instruments must be able to detect extremely weak laser return signals from high altitudes including orbital distance. The signals have a wide dynamic range caused by the variability in atmospheric transmission and surface reflectance under a fast moving spacecraft. Ideally, lidar detectors should be able to detect laser signal return pulses at the single photon level and produce linear output for multiple photon events. Silicon avalanche photodiode (APO) detectors have been used in most space lidar receivers to date. Their sensitivity is typically hundreds of photons per pulse, and is limited by the quantum efficiency, APO gain noise, dark current, and preamplifier noise. NASA is pursuing three approaches for a 16-channel laser photoreceiver for use on the next generation direct-detection airborne and spacebome lidars. We present our measurement results and a comparison of their performance.
    Keywords: Electronics and Electrical Engineering; Optics
    Type: LEGNEW-OLDGSFC-GSFC-LN-1186 , Society of Photo-Instrumentation Engineers (SPIE) Defense, Security and Sensing Conference; Aug 21, 2011 - Aug 26, 2011; San Diego, CA; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 4
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    Optimetrics for Precise Navigation (2017)
    In:  CASI
    Details
    Publication Date: 2019-08-13
    Description: Optimetrics for Precise Navigation will be implemented on existing optical communication links. The ranging and Doppler measurements are conducted over communication data frame and clock. The measurement accuracy is two orders of magnitude better than TDRSS. It also has other advantages of: The high optical carrier frequency enables: (1) Immunity from ionosphere and interplanetary Plasma noise floor, which is a performance limitation for RF tracking; and (2) High antenna gain reduces terminal size and volume, enables high precision tracking in Cubesat, and in deep space smallsat. High Optical Pointing Precision provides: (a) spacecraft orientation, (b) Minimal additional hardware to implement Precise Optimetrics over optical comm link; and (c) Continuous optical carrier phase measurement will enable the system presented here to accept future optical frequency standard with much higher clock accuracy.
    Keywords: Space Communications, Spacecraft Communications, Command and Tracking
    Type: GSFC-E-DAA-TN39336 , SCaN Workshop on Emerging Technologies for Autonomous Space Navigation; Feb 16, 2017; Washington, DC; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 5
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    Compact Coherent Laser Ranging (CCLR) (2019)
    In:  CASI
    Details
    Publication Date: 2019-08-30
    Description: Presents a design to develop a Compact Coherent Laser Ranging with the following goals: Match the performance as GRACE-FO, with much reduced SWaP to fit on mini-Sat or CubeSat; Enables low cost and more frequent LL-SST gravitational missions; Immunes from ionosphere propagation delay with optical ranging; Increases the body pointing capability due to small satellite.
    Keywords: Space Communications, Spacecraft Communications, Command and Tracking; Instrumentation and Photography
    Type: GSFC-E-DAA-TN72283
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 6
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    Metric Tracking Services in the Era of Optical Communications (2019)
    In:  CASI
    Details
    Publication Date: 2019-10-31
    Description: The Space Communications and Navigation program, at the National Aeronautics and Space Administration, is developing free-space optical communications technology to facilitate the next generation of space missions in near-Earth, Lunar, and planetary space. A discussion of optimetric observation performance and hardware-in-the-loop test results are presented. Simulation of orbit-determination for LEO and Lunar spacecraft relying on optimetric tracking extends raw observation accuracy to realizable orbit-determination performance. Potential science and operational applications are reviewed, along with NASA's approach for developing optimetric technology. Current investments in developing optimetric hardware and plans for NASA's future optical communications network define the path for a future operational optimetric capability in the 2020's and beyond.
    Keywords: Space Communications, Spacecraft Communications, Command and Tracking
    Type: IAC-19-B2.6.7 , HQ-E-DAA-TN74106 , International Astronautical Congress (IAC); Oct 21, 2019 - Oct 25, 2019; Washington, DC; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 7
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    Low-Noise Free-Running High-Rate Photon-Counting for Space Communication and Ranging (2016)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: We present performance data for low-noise free-running high-rate photon counting method for space optical communication and ranging. NASA GSFC is testing the performance of two types of novel photon-counting detectors 1) a 2x8 mercury cadmium telluride (HgCdTe) avalanche array made by DRS Inc., and a 2) a commercial 2880-element silicon avalanche photodiode (APD) array. We successfully measured real-time communication performance using both the 2 detected-photon threshold and logic AND-gate coincidence methods. Use of these methods allows mitigation of dark count, after-pulsing and background noise effects without using other method of Time Gating The HgCdTe APD array routinely demonstrated very high photon detection efficiencies ((is) greater than 50%) at near infrared wavelength. The commercial silicon APD array exhibited a fast output with rise times of 300 ps and pulse widths of 600 ps. On-chip individually filtered signals from the entire array were multiplexed onto a single fast output. NASA GSFC has tested both detectors for their potential application for space communications and ranging. We developed and compare their performances using both the 2 detected photon threshold and coincidence methods.
    Keywords: Communications and Radar
    Type: GSFC-E-DAA-TN30890 , SPIE Photonics West; Feb 13, 2016 - Feb 18, 2016; San Francisco, CA; United States
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    NASA TECHNICAL REPORTS
  • 8
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    High Precision Ranging and Range-Rate Measurements over Free-Space-Laser Communication Link (2016)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: We present a high-precision ranging and range-rate measurement system via an optical-ranging or combined ranging-communication link. A complete bench-top optical communication system was built. It included a ground terminal and a space terminal. Ranging and range rate tests were conducted in two configurations. In the communication configuration with 622 data rate, we achieved a two-way range-rate error of 2 microns/s, or a modified Allan deviation of 9 x 10 (exp -15) with 10 second averaging time. Ranging and range-rate as a function of Bit Error Rate of the communication link is reported. They are not sensitive to the link error rate. In the single-frequency amplitude modulation mode, we report a two-way range rate error of 0.8 microns/s, or a modified Allan deviation of 2.6 x 10 (exp -15) with 10 second averaging time. We identified the major noise sources in the current system as the transmitter modulation injected noise and receiver electronics generated noise. A new improved system will be constructed to further improve the system performance for both operating modes.
    Keywords: Communications and Radar
    Type: GSFC-E-DAA-TN28840 , IEEE Aerospace Conference; Mar 05, 2016 - Mar 12, 2016; Big Sky, MT; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 9
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    Continuous Carrier Optical Phase Optometric Measurement over Coherent Optical Communication Link (2018)
    In:  CASI
    Details
    Publication Date: 2019-08-27
    Description: An apparatus for measuring a distance between a first and second terminal includes a frame counter for determining a number of data frames traversing a distance between the first terminal 105 and the second terminal, a frame bit counter for determining a number of data clock bits offset between a transmitted data frame and a concurrently received data frame, a data clock phase detector for determining a phase difference between an RF data clock for the transmitted data frame and an RF data clock for the concurrently received data frame, and an optical carrier phase detector for determining a phase difference between an optical carrier used to transmit the transmitted data frame and an optical carrier for the concurrently received data frame. The distance between the first and second terminal is determined from a round trip transit time T between the first and second terminals.
    Keywords: Electronics and Electrical Engineering
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    NASA TECHNICAL REPORTS
  • 10
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    Apparatus and Method to Enable Precision and Fast Laser Frequency Tuning (2015)
    In:  CASI
    Details
    Publication Date: 2019-08-27
    Description: An apparatus and method is provided to enable precision and fast laser frequency tuning. For instance, a fast tunable slave laser may be dynamically offset-locked to a reference laser line using an optical phase-locked loop. The slave laser is heterodyned against a reference laser line to generate a beatnote that is subsequently frequency divided. The phase difference between the divided beatnote and a reference signal may be detected to generate an error signal proportional to the phase difference. The error signal is converted into appropriate feedback signals to phase lock the divided beatnote to the reference signal. The slave laser frequency target may be rapidly changed based on a combination of a dynamically changing frequency of the reference signal, the frequency dividing factor, and an effective polarity of the error signal. Feed-forward signals may be generated to accelerate the slave laser frequency switching through laser tuning ports.
    Keywords: Lasers and Masers
    Format: application/pdf
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    NASA TECHNICAL REPORTS
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