TY - JOUR
T1 - Coastal sea-surface wave measurements using software-based GPS reflectometers in Lanyu, Taiwan
AU - Tsai, Lung Chih
AU - Su, Shin Yi
AU - Chien, Hwa
AU - Liu, Chao Han
AU - Schuh, Harald
AU - Wickert, Jens
AU - Alizadeh, Mohamad Mahdi
N1 - Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2021/10
Y1 - 2021/10
N2 - A low-cost transportable software-based global positioning system reflectometry (GPS-R) scheme, which can measure sea-surface wave frequency, period, and speed, is proposed and described. We designed and implemented an appropriate software receiver to acquire and track GPS-R L1-band C/A code signals in near real time. At Lanyu, Taiwan, a research platform has been built with two software-based GPS-R receivers overlooking the seas in the east-northeast and southwest directions. Additionally, we propose applying the maximum entropy method for the spectral analyses of recorded time series of GPS-R signal acquisition data and derive the mean frequencies, periods, and speeds of random sea-surface waves. The derived sea-surface wave frequencies have been compared and validated against buoy measurements and Weather Research and Forecasting (WRF) model data around Lanyu Island. The results show that the buoy wave heights and the modeled WRF wave heights have linear correlation coefficients of 0.64 and 0.47, respectively, with the GPS-R wave frequency measurements. The observed coastal sea area has a maximum horizontal distance of approximately 20 km from station Lanyu (22.037°N, 121.559°E). Thus, the corresponding mapping products of the sea-surface wave period and speed are presented with wave propagation footprints of the first Fresnel zone sizes.
AB - A low-cost transportable software-based global positioning system reflectometry (GPS-R) scheme, which can measure sea-surface wave frequency, period, and speed, is proposed and described. We designed and implemented an appropriate software receiver to acquire and track GPS-R L1-band C/A code signals in near real time. At Lanyu, Taiwan, a research platform has been built with two software-based GPS-R receivers overlooking the seas in the east-northeast and southwest directions. Additionally, we propose applying the maximum entropy method for the spectral analyses of recorded time series of GPS-R signal acquisition data and derive the mean frequencies, periods, and speeds of random sea-surface waves. The derived sea-surface wave frequencies have been compared and validated against buoy measurements and Weather Research and Forecasting (WRF) model data around Lanyu Island. The results show that the buoy wave heights and the modeled WRF wave heights have linear correlation coefficients of 0.64 and 0.47, respectively, with the GPS-R wave frequency measurements. The observed coastal sea area has a maximum horizontal distance of approximately 20 km from station Lanyu (22.037°N, 121.559°E). Thus, the corresponding mapping products of the sea-surface wave period and speed are presented with wave propagation footprints of the first Fresnel zone sizes.
KW - GNSS reflectometry
KW - GPS L1-band C/A code signal acquisition
KW - Random sea-surface wave measurement
KW - Software-based GPS/GNSS receiver
UR - http://www.scopus.com/inward/record.url?scp=85111965489&partnerID=8YFLogxK
U2 - 10.1007/s10291-021-01167-2
DO - 10.1007/s10291-021-01167-2
M3 - 期刊論文
AN - SCOPUS:85111965489
SN - 1080-5370
VL - 25
JO - GPS Solutions
JF - GPS Solutions
IS - 4
M1 - 133
ER -