GNSS augmentation

About: GNSS augmentation is a research topic. Over the lifetime, 2478 publications have been published within this topic receiving 28513 citations. The topic is also known as: SBAS & Satellite Based Augmentation System.

Feasibility of GNSS receivers for satellite navigation in GEO and higher altitudes

Abstract: GPS is successfully used for spacecraft navigation in low Earth orbits. This paper investigates the feasibility of Global Navigation Satellite System (GNSS) receivers for spacecraft navigation in GEO, GTO, and higher orbits. The study is based on the experience gained at EADS Astrium from developing GNSS receivers for satellites as well as the requirements and feedback from satellite manufacturers and operators. The performance results are computed using the onboard navigation core algorithms of the MosaicGNSS receiver and the LION Navigator.

Gnss receiving device and positioning method

Abstract: PROBLEM TO BE SOLVED: To detect existence of an influence of multipath; to reduce the influence when the influence of multipath exists; and to improve measurement accuracy. SOLUTION: This GNSS (Global Navigation Satellite System) receiving device for calculating a position based on each positioning signal transmitted from a plurality of GNSS satellites is equipped with a multipath determination means for determining whether the positioning signal is received after being influenced by the multipath or not, based on a time characteristic of a pseudo distance determined based on the positioning signal; a phase difference zero point calculation means for determining a zero point where a phase of a direct wave becomes equal to a phase of a reflected wave based on the time characteristic of the pseudo distance, when determined that the positioning signal is received after being influenced by the multipath; a pseudo distance correction means for correcting the pseudo distance based on the time characteristic of an integrated value of a Doppler frequency determined based on the positioning signal and on the zero point determined by the phase difference zero point calculation means; and a positioning operation means for determining a position based on the corrected pseudo distance. COPYRIGHT: (C)2009,JPO&INPIT

Satellite-Based Augmentation Systems

Abstract: Satellite-Based Augmentation Systems (SBASs) provide three main benefits to users of the augmented satnav system that includes integrity, accuracy, and availability. This chapter provides a brief history of SBAS, followed by an overview of SBAS and of some specific SBASs. SBAS coverage continues to expand, as existing systems add more satellites and ground reference stations, and additional systems are implemented. SBAS signals are designed primarily to provide data that communicates the integrity of augmented signals, as well as corrections that improve the accuracy of augmented signals; only some SBAS signals are currently approved for ranging. The high degree of interoperability between SBAS signals and corresponding GPS signals enables SBAS functionality to be added to a GPS receiver with minimal additional complexity. SBAS signals employ BPSK-R spreading modulations, no pilot components, and other design characteristics very similar to the GPS C/A code signal and L5 signal.

Application of sbas pseudorange and carrier phase signals to precise instantaneous single-frequency positioning

Abstract: This research evaluates the potential benefits of the tightly combined processing of a global navigation satellite system together with the additional ranging observations from a satellite based augmentation system. In specific, the experiment presents performance of precise instantaneous single-frequency positioning based on European Galileo and EGNOS navigation systems. Due to currently low number of Galileo satellites, the test observational data were obtained with hardware GNSS signal simulator. All calculations were performed with in-house developed software - GINPOS. The results show that it is possible to obtain improvement in the accuracy and reliability of single-frequency precise positioning when including observations from SBAS systems. However, one must take into account that at middle latitudes EGNOS satellites are observed at low elevations what results in higher atmospheric errors affecting its signals.

Study of GNSS-R Techniques for FORMOSAT Mission

Abstract: The use of global navigation satellite system (GNSS) for remote sensing and environmental monitoring has been an important research topic in recent years due to the omnipresence and performance of GNSS signals. The FORMOSAT-3 and the upcoming FORMOSAT-7 have exploited the potential of GNSS-based radio occultation for profiling the ionosphere and atmosphere so that better understanding of space weather and higher accuracy in numerical weather prediction are achieved. In addition to occultation through the refraction of GNSS signals, reflection of GNSS signals is becoming an important remote sensing tool in probing sea surface height, wind velocity, salinity, soil moisture, roughness, and snow depth. This paper presents a development plan of a space GNSS-R experiment. The design of the GNSS-R receiver payload for a FORMOSAT-7 satellite is discussed with emphasis on processing of satellite-based augmentation system (SBAS) and regional navigation satellite system (RNSS) signals. It is shown that SBAS/RNSS signals can enhance GNSS reflectometry mission in terms of the increase of reflection events and repetition of the reflection location. Evidences of SBAS reflection on UK TDS-1 are reported to show that the SBAS reflected signals can indeed be processed even though the SBAS satellites are located at a geostationary orbit.