Comparing the accuracy and precision of smartphone and specialist handheld GNSS receivers for use in ecological fieldwork

Osborne, Andrew ORCID: https://orcid.org/0000-0001-6338-6295, Mossman, Hannah ORCID: https://orcid.org/0000-0001-5958-5320, Caporn, Simon ORCID: https://orcid.org/0000-0002-4963-5360 and Coulthard, Emma ORCID: https://orcid.org/0000-0001-8935-9092 (2025) Comparing the accuracy and precision of smartphone and specialist handheld GNSS receivers for use in ecological fieldwork. Ecological Solutions and Evidence, 6 (1). e70015. ISSN 2688-8319

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Abstract

Smartphones are handheld computers and multichannel communication devices that carry an array of sensors and can link with specialist external devices. These powerful tools have an established role in biological recording and ecological surveying. The ability to geolocate accurately is frequently essential to ecological fieldwork. This field study aimed to test the performance of a compact/handheld surveyor‐grade GNSS receiver, functioning as an external sensor, compared to smartphones' inbuilt GNSS receivers and a standard‐grade external GNSS receiver. We devised a series of survey protocols to test the horizontal accuracy of GNSS receivers in static and dynamic scenarios typical of ecology fieldwork, estimating the horizontal distance of GNSS measurements under ‘open sky’ conditions from a base station geolocated with centimetre accuracy. Protocols were designed to test the capabilities of GNSS receivers; the absolute horizontal accuracy and precision in static surveys and performance in dynamic surveys, walking a transect with frequent changes of direction, or roaming across the survey area, requiring the GNSS to rapidly re‐establish a position fix. In all survey protocols, the surveyor‐grade GNSS performed significantly better with lower horizontal distance estimates at the 50th centile and more consistent performance at the 95th centile than the other GNSS receivers, giving median distance estimates of 0.5–1.1 m. The median horizontal accuracy of inbuilt GNSS receivers in this trial was 0.9–3.4 m under ‘open sky’ conditions. Practical implication: The smartphone GNSS receivers that we tested were accurate to within a few meters. Linking the smartphone with a moderately priced compact/handheld external GNSS receiver significantly improved performance.