{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:38:01Z","timestamp":1760243881328,"version":"build-2065373602"},"reference-count":16,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2010,3,25]],"date-time":"2010-03-25T00:00:00Z","timestamp":1269475200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper investigates the potential vertical guidance performance of global positioning system (GPS)\/wide area augmentation system (WAAS) user avionics sensor when the modernized GPS and Galileo are available. This paper will first investigate the airborne receiver code noise and multipath (CNMP) confidence (\u03c3air). The \u03c3air will be the dominant factor in the availability analysis of an L1-L5 dual-frequency GPS\/WAAS user avionics sensor. This paper uses the MATLAB Algorithm Availability Simulation Tool (MAAST) to determine the required values for the \u03c3air, so that an L1-L5 dual-frequency GPS\/WAAS user avionics sensor can meet the vertical guidance requirements of APproach with Vertical guidance (APV) II and CATegory (CAT) I over conterminous United States (CONUS). A modified MAAST that includes the Galileo satellite constellation is used to determine under what user configurations WAAS could be an APV II system or a CAT I system over CONUS. Furthermore, this paper examines the combinations of possible improvements in signal models and the addition of Galileo to determine if GPS\/WAAS user avionics sensor could achieve 10 m Vertical Alert Limit (VAL) within the service volume. Finally, this paper presents the future vertical guidance performance of GPS user avionics sensor for the United States\u2019 WAAS, Japanese MTSAT-based satellite augmentation system (MSAS) and European geostationary navigation overlay service (EGNOS).<\/jats:p>","DOI":"10.3390\/s100402609","type":"journal-article","created":{"date-parts":[[2010,3,25]],"date-time":"2010-03-25T12:20:28Z","timestamp":1269519628000},"page":"2609-2625","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Vertical Guidance Performance Analysis of the L1-L5 Dual-Frequency GPS\/WAAS User Avionics Sensor"],"prefix":"10.3390","volume":"10","author":[{"given":"Shau-Shiun","family":"Jan","sequence":"first","affiliation":[{"name":"Institute of Civil Aviation, National Cheng Kung University, Tainan 70101, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2010,3,25]]},"reference":[{"key":"ref_1","unstructured":"Misra, P., and Enge, P. (2006). Global Positioning System Signal, Measurements, and Performance, Ganga-Jamuna Press. [2nd ed.]."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Parkinson, B.W., and Spilker, J.J. (1996). Global Positioning System: Theory and Application, AIAA Publication.","DOI":"10.2514\/4.866395"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1063","DOI":"10.1109\/5.533954","article-title":"Wide Area Augmentation of the Global Positioning System","volume":"84","author":"Enge","year":"1996","journal-title":"Proc. IEEE"},{"key":"ref_4","unstructured":"ICD-GPS-200C (1993). NAVSTAR GPS Space Segment \/ Navigation User Interface, Arinc Research Corporation. and subsequent IRNs 1 through 5."},{"key":"ref_5","unstructured":"Tytgat, L., and Campagne, P. (2000, January September). Galileo: A New GNSS Designed for the Benefit of All Kind of Civil Users. Salt Lake City, UT, USA."},{"key":"ref_6","unstructured":"(2002). Navigation and Landing Transition Strategy, Federal Aviation Administration (FAA)."},{"key":"ref_7","unstructured":"RTCA SC-159 (2006). Minimum Operational Performance Standard for Global Positioning System\/Wide Area Augmentation System Airborne Equipment, RTCA\/DO-229D, RTCA Inc."},{"key":"ref_8","unstructured":"Walter, T., Enge, P., and Hansen, A. (1997, January September). A Proposed Integrity Equation for WAAS MOPS. Kansas City, MI, USA."},{"key":"ref_9","unstructured":"Jan, S.S., Chan, W., Walter, T., and Enge, P. (2001, January September). MATLAB Simulation Toolset for SBAS Availability Analysis. Salt Lake City, UT, USA."},{"key":"ref_10","unstructured":"Stanford GPS Research Laboratory web page. Available online: http:\/\/waas.stanford.edu\/about\/resources.htm (accessed on 19 March 2010)."},{"key":"ref_11","unstructured":"Walter, T., Enge, P., and Reddan, P. (2004, January September). Modernizing WAAS. Long Beach, CA, USA."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1109\/TAES.2008.4516994","article-title":"Improving GPS-Based Landing System Performance Using an Empirical Barometric Altimeter Confidence Bound","volume":"44","author":"Jan","year":"2008","journal-title":"IEEE T. Aero. Elec. Sys"},{"key":"ref_13","unstructured":"Jan, S.S. (2003). Aircraft Landing Using a Modernized Global Position System and the Wide Area Augmentation System, Ph.D. thesis, Department of Aeronautics and Astronautics, Stanford University, USA,."},{"key":"ref_14","unstructured":"Jan, S.S., Walter, T., and Enge, P. (2003, January January). Graceful Reversion from Dual to Single Frequency WAAS. Anaheim, CA, USA."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1109\/5.736345","article-title":"Local Area Augmentation of the GPS for the Precision Approach of Aircraft","volume":"87","author":"Enge","year":"1999","journal-title":"Proc. IEEE"},{"key":"ref_16","unstructured":"Jan, S.S. (2005, January January). Enabling CAT I Capabilities on Dual-Frequency WAAS. San Diego, CA, USA."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/10\/4\/2609\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T22:01:54Z","timestamp":1760220114000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/10\/4\/2609"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2010,3,25]]},"references-count":16,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2010,4]]}},"alternative-id":["s100402609"],"URL":"https:\/\/doi.org\/10.3390\/s100402609","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2010,3,25]]}}}