Archives

Integer ambiguity validation: Still an open problem?

July 30, 2007 - By

By Sandra Verhagen High-precision Global Navigation Satellite System (GNSS) positioning results are obtained with carrier phase measurements, once the integer cycle ambiguities have been successfully resolved. The position solution is obtained in four steps: 1. Float solution:least-squares, discarding integer nature. 2. Integer solution: real-valued float ambiguities mapped to integer-valued ambiguities.Examples of integer estimators (Teunissen, 1998a): • Integer Least-Squares: optimal, requires... read more

This article is tagged with , and posted in Algorithms & Methods, Tech Talk

Survey Perspectives – July 2007

July 30, 2007 - By

The European Geostationary Navigation Overlay Service (EGNOS) is Europe´s version of the U.S. Wide Area Augmentation System (WAAS) with essentially the same mission. It offers GPS users in Europe more accurate and reliably GPS positioning. Like WAAS, EGNOS focuses on improving the integrity and accuracy of autonomous GPS positioning primarily by modeling refraction caused by the ionosphere. Also, EGNOS was designed to be compatible with WAAS so your WAAS-enabled receiver will work with EGNOS just fine. read more

This article is tagged with and posted in Newsletter Editorials, Opinions, Survey, Survey Scene

Broadcom Completes Acquisition of Global Locate

July 13, 2007 - By

Telecom chip maker Broadcom Corp. said Thursday evening that it had completed its acquisition of Global Locate Inc., a privately held provider of GPS and assisted-GPS chips and related software. read more