A new ambiguity resolution method based on searching in both geometric and ambiguity spaces

Wu Chen, Ying Xu, Duojie Weng

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

Abstract

Effective ambiguity resolution methods are crucial for GPS carrier phase positioning, particularly for Real-Time Kinematic (RTK) operation. Ambiguity resolution is based on search methods, and the search can be either in geometric or ambiguity spaces. For example, the ambiguity function method is based on geometric space search. For ambiguity resolution validation, majority algorithms are based on the comparison of the smallest and the second smallest sum of residuals. Success Rate of ambiguity resolution can also be used for the validation process. However, the existing methods are difficult to answer the question of why the ambiguity cannot be fixed if the validation test is not passed. In this paper, we propose a new ambiguity resolution method which searches both geometric and ambiguity spaces. With this new approach, we can clearly identify the reasons why the ambiguity cannot be fixed, with the following possible reasons: Weak geometry, outliers in carrier phase measurements, or the measurement errors are too large. For the geometry reason, we have to wait for more time for ambiguity resolution. When there are outliers in the measurements, RAIM methods can be used to detect those measurements with errors are significantly larger than others. If the carrier phase measurements noise level is too high, the ambiguity fixing solution will not be available for the positioning solution.
Original languageEnglish
Title of host publication27th International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2014
PublisherInstitute of Navigation
Pages601-608
Number of pages8
Volume1
ISBN (Electronic)9781634399913
Publication statusPublished - 1 Jan 2014
Event27th International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2014 - Tampa, United States
Duration: 8 Sep 201412 Sep 2014

Conference

Conference27th International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2014
Country/TerritoryUnited States
CityTampa
Period8/09/1412/09/14

Keywords

  • Ambiguity resolution validations
  • GPS
  • Mis-fixing condition
  • R-ratio test
  • Spatial separability

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Aerospace Engineering
  • Computer Science Applications
  • Software

Cite this