Assessment of free - space lasercomm for DOD's T&E applications. (2009)
Hemmati, Hamid, Charles, Jeffrey, Piazzolla, Sabino
For test and evaluation of airplanes, it is desirable to telemeter large volumes of data to the ground. This telemetry has generally utilized W communication systems, which have relatively low data...
Simplified lasercom system architecture using a disturbance-free platform (2008)
Chen, Chien-Chung, Hemmati, Hamid, Biswas, Abhijit, Ortiz, Gerardo, Farr, William, Pedreiro, Nelson
A simplified laser communications (lasercom) system architecture, primarily for a deep-space flight transceivers, can be realized by decoupling the lasercom optical components from the host...
Earth-image tracking in the IR for deep space optical communications (2008)
Hemmati, Hamid, Chen, Yinging, Lee, Shinhak, Ortiz, Gerard G.
Sub-microradian level laser beam pointing to an Earth-based receiver is required for deep space optical communications. This requires a beacon emanated from Earth towards the spacecraft. The beacon...
Integrated network architecture for sustained human and robotic exploration (2008)
Noreen, Gary, Cesarone, Robert, Deutsch, Leslie, Edwards, Charles, Soloff, Jason, Ely, Todd, ...
The National Aeronautics and Space Administration (NASA) Exploration Systems Enterprise is planning a series of human and robotic missions to the Earth's moon and to Mars. These missions will require...
FREQUENCY AGILE Tm,Ho:YLF LOCAL OSCILLATOR FOR A SCANNING DOPPLER WIND LIDAR IN EARTH ORBIT (2007)
Robert T, Robert T, Kfen. Zies, Hamid Hemmati, Hamid Hemmati, Carlos Esproles, ...
A compact cw Tm,Ho:YLF laser with single-mode tunability over +/- 4 GHz has been developed into a modular unit containing an isolator and photomixer for offset tuning of the LO from a master...
Hemmati, Hamid, Chen, Yijiang, Crossfield, Ian
With the goal of reducing the surface wavefront error of low-cost multi-meter-diameter mirrors from about 10 waves peak-to-valley (P-V), at lpm wavelength, to approximately 1-wave or less, we...
Low-cost large aperture telescopes for optical communications (2006)
Low-cost, large-aperture optical receivers are required to form an affordable optical ground receiver network for laser communications. Among the ground receiver station’s multiple subsystems,...
Feasibility of utilizing large diameter custom designed and fabricated Fresnel lenses as the front optical aperture for Earth-based reception of optical communication signals from remote spacecraft...
Optical space communications at JPL (2006)
Subsytem and system level technology development at JPL for free-space laser communications from both deep space and near Earth is described. These include acquisition, tracking, and pointing, laser...
Optical systems for free-space laser communications (2006)
An overview of optical systems utilized in JPL's Optical Communications research is provided here. These include discussions on the flight terminal optics, the ground receiver aperture and the uplink...
Integrated network architecture for sustained human and robotic exploration (2005)
Noreen, Gary K., Cesarone, Robert, Deutsch, Leslie, Edwards, Charlie, Soloff, Jason, Ely, Todd, ...
The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate is planning a series of human and robotic missions to the Earth's moon and to Mars. These missions...
Optical Communication Subsystem for the X200 Series of Planetary Missions (2004)
Hemmati, Hamid, Lesh, James R.
NASA has started a major new Advanced Deep Space System Development (a.k.a x2000) Program at JPL. The objective of this program is to develop and space-qualify (in a total system environment)...
Frequency Agile Tm,Ho:YLF Local Oscillator for a Scanning Doppler wind Lidar in Earth Orbit (2004)
Menzies, Robert T., Hemmati, Hamid, Esproles, Carlos
A compact cw Tm,Ho:YLF laser with single-mode tunability over +/-4 GHz has been developed into a modular unit containing an isolator and photomixer for offset tuning of the LO from a master...