GPS signals are sparse and weak at high altitudes above the GPS constellation; this includes GEO and HEO orbit regimes. Spacecraft operating here need a high-sensitivity receiver capable of acquiring and tracking these weak signals throughout their orbits. Most space GPS receivers are designed to operate in the LEO regime below the GPS constellation and will perform poorly at high altitude. The Goddard Space Flight Center (GSFC) Navigator GPS receiver is designed for above-the-constellation applications and can provide adequate performance for many missions. The innovation described here provides large sensitivity increase through improvement of the receiver’s antenna gain. The technology can be applied to a standard LEO GPS receiver to enable adequate high-altitude performance, or to a specialized high-altitude receiver, like the GSFC Navigator, to further improve its high-altitude performance. The innovation can also be used to mitigate interference, including multipath and RF

Emergency Locator Transmitter (ELT) Shipsets

TBMG-22304

06/01/2015

McMurdo Group Lanham, MD 240-790-0600

Boeing: Building A Better GPS

1193502/25/2015

Learn more about how Boeing innovates at http://www.buildsomethingbetter.com. As the number of GPS devices increases globally, Boeing-built satellites are helping to sustain and modernize the GPS constellation. Bringing innovations from their airplane assembly lines to GPS production, Boeing is helping to assure GPS service is available wherever, whenever.

Method for Performing GPS L1 C/A Measurements in Wideband Jamming and Interference

TBMG-2153302/01/2015

For effective range safety, global positioning system (GPS) metric tracking must be robust to interference with, and jamming of, GPS signals. The conventional approach to mitigating interference and jamming is to use a Controlled Reception Pattern Antenna (CRPA). These few-element phased arrays are used to steer nulls in the directions of interference sources, and/or to point beams in the directions of GPS satellites. The use of CRPAs is limited by their cost and size, as well as the difficulties of integrating the array into a platform. The problems are compounded for a launch vehicle, which must acquire and track GPS signals at high speed and acceleration, and undergo vibration and temperature conditions not common to CRPA use.

Determination of Virtual Topographic Routes to Powertrain Performance Analysis

2014-36-042209/30/2014

Powertrain performance analysis is applied by the automotive industry to verify the dynamic performance of the vehicles, which is an outcome of the combination of the engine, the gear box, the driveline, the carrier ratio and the tire size. On this analysis, the main non powertrain factors are the total combined vehicle weight and the route topography. The total combined vehicle weight is a known factor. It is related to the vehicle application and it is restricted to pre-established limits. In general, the route topography is the unlikely factor, due to the huge coverage of the potential paths. Traditionally, the route topography determination is carry out supported by global positioning system (GPS) devices. Appling this methodology, the full route must be tracked by a vehicle equipped with GPS. Its complexity, time and cost increase in case of multiple routes must be tracked, in places geographically remote each other, as different regions, provinces, states or countries. The

Cezar, Fabio Andreassa Guedes, de Stefani, Armando Marcelo Rivero, Esperidião, Adriano, Kubo, Pablo Yugo Yoshiura

Gridded Atmosphere Products from GPS Radio Occultation Measurements with Bayesian Interpolation Technique

TBMG-19538

05/01/2014

GPS radio occultation measurements are vital for climate monitoring and atmospheric temperature change detection. However, the data are irregularly distributed in space and time, which makes it inconvenient for many applications.