{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,18]],"date-time":"2026-04-18T21:51:37Z","timestamp":1776549097069,"version":"3.51.2"},"reference-count":28,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2020,11,13]],"date-time":"2020-11-13T00:00:00Z","timestamp":1605225600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003524","name":"Ministry of Business, Innovation and Employment","doi-asserted-by":"publisher","award":["UOOX0904"],"award-info":[{"award-number":["UOOX0904"]}],"id":[{"id":"10.13039\/501100003524","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A new approach to GPS positioning is described in which the post-processing of ultra-short sequences of captured GPS signal data can produce an estimate of receiver location. The algorithm, called \u2018FastFix\u2019, needs only 2\u20134 ms of stored L1-band data sampled at \u223c16 MHz. The algorithm uses a least-squares optimization to estimate receiver position and GPS time from measurements of the relative codephase, and Doppler-shift of GNSS satellite signals. A practical application of this algorithm is demonstrated in a small, lightweight, low-power tracking tag that periodically wakes-up, records and stores 4 ms of GPS L1-band signal and returns to a low-power state\u2014reducing power requirements by a factor of \u223c10,000 compared to typical GPS devices. Stationary device testing shows a median error of 27.7 m with a small patch antenna. Results from deployment of this tag on adult Royal Albatross show excellent performance, demonstrating lightweight, solar-powered, long-term tracking of these remarkable birds. This work was performed on the GPS system; however, the algorithm is applicable to other GNSS systems.<\/jats:p>","DOI":"10.3390\/s20226480","type":"journal-article","created":{"date-parts":[[2020,11,13]],"date-time":"2020-11-13T08:44:02Z","timestamp":1605257042000},"page":"6480","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Estimating Position from Millisecond Samples of GPS Signals (the \u201cFastFix\u201d Algorithm)"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2022-0380","authenticated-orcid":false,"given":"Timothy C. A.","family":"Molteno","sequence":"first","affiliation":[{"name":"Department of Physics, University of Otago, Dunedin 9016, New Zealand"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1071\/WR10211","article-title":"Wildlife tracking technology options and cost considerations","volume":"38","author":"Thomas","year":"2012","journal-title":"Wildl. Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"78","DOI":"10.2174\/1874447800903010078","article-title":"Assessing real time GPS asset tracking for timber haulage","volume":"3","author":"Devlin","year":"2009","journal-title":"Open Transp. 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