Estimating GPS Signal Loss in a Natural Deciduous Forest Using Sky Photography
No Thumbnail Available
Authors
Wright, William C.
Wilkinson, Benjamin E.
Cropper, Wendell P.
Issue Date
2017
Type
journal-article
Language
Keywords
ArcGIS , Canopy Closure , Global Positioning System , Hemispherical sky-oriented photo , Image processing
Alternative Title
Abstract
Understanding how Global Positioning System (GPS) signals are influenced by vegetation structure allows for the determination of how specific technologies might be affected in certain forest environments. This study presents three different models that predict signal loss in a natural deciduous forest using fisheye photography. Relationships between terrestrial-based hemispherical sky-oriented photo (HSOP) measurements and GPS signal-to-noise ratios (SNRs) are explored. ArcGIS is used for image processing of HSOPs to rapidly estimate canopy closure (CC) at particular angles from zenith in forested areas. The difference between the observed SNR of GPS L-band signals under forest canopies to those observed in the open determines signal loss. CC values at different zenith angles inside the forest during four seasons are used to model signal attenuation. This article presents a canopy closure predictive model (CCPM), a model that includes the CCPM and incorporates the difference between the CC value in any season minus the CC in the winter, and a model that includes a seasonal component. The three models presented in this article yield adjusted R2 values between 0.60 and 0.62 and root mean square error range of 3.21 to 3.28 dB.
Description
Citation
William C. Wright, Benjamin E. Wilkinson & Wendell P. Cropper Jr. (2017) Estimating GPS Signal Loss in a Natural Deciduous Forest Using Sky Photography, Papers in Applied Geography, 3:2, 119-128, DOI: 10.1080/23754931.2016.1264990
Publisher
Papers in Applied Geography
License
Journal
Volume
Issue
PubMed ID
ISSN
2375-4931
2375-494X
2375-494X