Engineering topics

Pratt, Tim

Publications and source records attributed to Pratt, Tim.

4 records

DOE OSTI2024

Pathways Toward Electric Mobility: Communities LEAP in Hennepin County, Minnesota

This report presents the findings from a comprehensive community engagement initiative focused on advancing equitable transportation electrification in Hennepin County. This initiative responds to the critical need for inclusive and sustainable mobility solutions in the face of rising environmental and financial challenges in the transportation sector. This project has two goals. First, to learn what each community's priorities are and share them with the city, county, and state government to inform transportation plans and projects. Second, to bridge divides between government and community, building pathways for community-guided decision making on future transportation plans.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

NASA NTRS1993

Design and construction of a prototype ACTS propagation terminal

The launch schedule for the Advanced Communication Technology Satellite (ACTS) spacecraft did not leave sufficient time for completion of the prototype ACTS Propagation Terminals (APT) prior to initiation of the APT production phase. In fact, the approach used was to construct and test all subassemblies of the terminal with special emphasis on the technically challenging portions. These include the RF front end that uses a state-of-the-art down converter which integrates a low noise amplifier, mixer, post amplifier, filter, and local oscillator port frequency doubler into a single small package. In addition, a new digital receiver that uses the latest DSP technology was developed. Both of these subassemblies were thoroughly tested. The highest risk technology in the APT program was the digital receiver. Several candidate algorithms and DSP chips were investigated early on, primarily under JPL sponsorship. A receiver was constructed based on Texas Instruments chip. The final prototype digital receiver was one based on an Analog Devices chip. The design and test results are documented in a report prepared for this grant. A Primary Design Review (PDR) was conducted 30 May 1991, and a Critical Design Review was held 7 Jul. 1992. Final complete documentation of the APT's will appear in the form of three reports: a hardware description report, a report on the data collection code (ACTS VIEW), and a report on the preprocessing code.

Stutzman, Warren↗

NASA NTRS1992

The Virginia Tech OLYMPUS propagation experiment

Virginia Polytechnic Institute has been carrying out a comprehensive set of propagation measurements using the OLYMPUS satellite beacons at 12.5, 20, and 30 GHz since August 1990. Total power radiometers are also included in each terminal, and radiometer data are used both to set the absolute level of the beacon data and to predict path attenuation. Some results from the experiment set are presented.

Pratt, Tim↗

NASA NTRS1992

ACTS propagation terminal update

The activities at Virginia Polytechnic Institute and State University in preparation for the February 1993 launch of ACTS are summarized. ACTS propagation terminals (APT) are being constructed to receive the 20 and 27.5 GHz ACTS beacon signals. Total power radiometers operating at the same frequencies are integrated into the terminal for use in level setting. Recent progress and plans for APT's are reported.

Stutzman, Warren L.↗