Engineering topics

Spence, Thomas

Publications and source records attributed to Spence, Thomas.

4 records

NASA NTRS2016

Concept Design of a Multi-Band Shared Aperture Reflectarray/Reflector Antenna

A scalable dual-band (KaW) shared-aperture antenna system design has been developed as a proposed solution to meet the needs of the planned NASA Earth Science Aerosol, Clouds, and Ecosystem (ACE) mission. The design is comprised of a compact Cassegrain reflector/reflectarray with a fixed pointing W-band feed and a cross track scanned Ka-band Active Electronically Scanned Array (AESA). Critical Sub-scale prototype testing and flight tests have validated some of the key aspects of this innovative antenna design, including the low loss reflector/reflectarray surface.More recently the science community has expressed interest in a mission that offers the ability to measure precipitation in addition to clouds and aerosols. In this paper we present summaries of multiple designs that explore options for realizing a tri-frequency (KuKaW), shared-aperture antenna system to meet these science objectives. Design considerations include meeting performance requirements while emphasizing payload size, weight, prime power, and cost. The extensive trades and lessons learned from our previous dual-band ACE system development were utilized as the foundation for this work.

Doppler↗

NASA NTRS2016

Development of a Multi-Band Shared Aperture Reflectarray/Reflector Antenna Design for NASA

A dual-band (Ka/W) shared-aperture antenna system design has been developed as a proposed solution to meet the needs of NASA's planned Aerosol, Clouds, and Ecosystem (ACE) mission. The design is comprised of a compact Cassegrain reflector/reflect array with a fixed W-band feed and a cross track scanned Ka-band Active Electronically Scanned Array (AESA). Critical Sub-scale prototype testing and flight tests have validated some of the key aspects of this innovative antenna design, including the low loss reflector/reflect array surface. More recently the science community has expressed interest in a mission that offers the ability to measure precipitation (Ku- band with scanning) in addition to clouds and aerosols. In this paper we present findings from a design study that explores options for realizing a tri-frequency (Ku/Ka/W), shared-aperture antenna system to meet these science objectives. Design considerations included meeting performance requirements while striving to minimize payload size, weight, prime power, and cost. The extensive trades and lessons learned from the ACE system development were utilized as the foundation for this work.

doppler↗

NASA NTRS2016

Concept Design of a Multi-Band Shared Aperture Reflectarray/Reflector Antenna

A scalable dual-band (Ka/W) shared-aperture antenna system design has been developed as a proposed solution to meet the needs of the planned NASA Earth Science Aerosol, Clouds, and Ecosystem (ACE) mission. The design is comprised of a compact Cassegrain reflector/reflectarray with a fixed pointing W-band feed and a cross track scanned Ka-band Active Electronically Scanned Array (AESA). Critical Sub-scale prototype testing and flight tests have validated some of the key aspects of this innovative antenna design, including the low loss reflector/reflectarray surface. More recently the science community has expressed interest in a mission that offers the ability to measure precipitation in addition to clouds and aerosols. In this paper we present summaries of multiple designs that explore options for realizing a tri-frequency (Ku/Ka/W), shared-aperture antenna system to meet these science objectives. Design considerations include meeting performance requirements while emphasizing payload size, weight, prime power, and cost. The extensive trades and lessons learned from our previous dual-band ACE system development were utilized as the foundation for this work.

doppler↗

NASA NTRS2016

A Multi-Frequency Wide-Swath Spaceborne Cloud and Precipitation Imaging Radar

Microwave and millimeter-wave radars have proven their effectiveness in cloud and precipitation observations. The NASA Earth Science Decadal Survey (DS) Aerosol, Cloud and Ecosystems (ACE) mission calls for a dual-frequency cloud radar (W band 94 GHz and Ka-band 35 GHz) for global measurements of cloud microphysical properties. Recently, there have been discussions of utilizing a tri-frequency (KuKaW-band) radar for a combined ACE and Global Precipitation Measurement (GPM) follow-on mission that has evolved into the Cloud and Precipitation Process Mission (CaPPM) concept. In this presentation we will give an overview of the technology development efforts at the NASA Goddard Space Flight Center (GSFC) and at Northrop Grumman Electronic Systems (NGES) through projects funded by the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP). Our primary objective of this research is to advance the key enabling technologies for a tri-frequency (KuKaW-band) shared-aperture spaceborne imaging radar to provide unprecedented, simultaneous multi-frequency measurements that will enhance understanding of the effects of clouds and precipitation and their interaction on Earth climate change. Research effort has been focused on concept design and trade studies of the tri-frequency radar; investigating architectures that provide tri-band shared-aperture capability; advancing the development of the Ka band active electronically scanned array (AESA) transmitreceive (TR) module, and development of the advanced radar backend electronics.

imaging↗