Retrieval of Ocean Surface Wind Speed Using Reflected BPSK/BOC Signals

Wang, Hao Yu; Juang, Jyh‐Ching

doi:10.3390/rs12172698

Cited by 8 publications

(4 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unfortunately, due to the limited amount of Beidou GNSS-R data available at present, it is impossible to make a conclusive analysis on the geophysical sensitivity of the Beidou signal. Wang et al [53] proposed a new GNSS-R method for measuring sea-surface wind speed (i.e., a composite delay-Doppler map, cDDM). A GNSS-R receiver can receive BPSK and BOC signals simultaneously in the same frequency band (such as GPS III L1 C/A and L1C or QZSS L1 C/A and L1C) and process the signals to generate GNSS-R measurements.…”

Section: Sea-surface Wind Speed Estimationmentioning

confidence: 99%

“…Additionally, as mentioned earlier, the UK, US and China successfully launched TechDemoSat-1 (TDS-1) [38], Cyclone Global Navigation Satellite System (CYGNSS) [27] and BuFeng-1 A/B satellites in 2014, 2016 and 2019 [30], respectively. In addition, there are FSSCat [51,[95][96][97] and TRITON [53,[98][99][100] satellite missions dedicated to GNSS-R applications. Although this technique has been successfully applied to the retrieval of various geophysical parameters [21,[101][102][103][104][105][106], research using the technology to obtain rainfall information is very limited.…”

Section: Spaceborne Rainfall Detection and Rainfall Intensity Retrievalmentioning

confidence: 99%

See 1 more Smart Citation

Spaceborne GNSS Reflectometry

Han

et al. 2022

Remote Sensing

View full text Add to dashboard Cite

This article presents a review on spaceborne Global Navigation Satellite System Reflectometry (GNSS-R), which is an important part of GNSS-R technology and has attracted great attention from academia, industry and government agencies in recent years. Compared with ground-based and airborne GNSS-R approaches, spaceborne GNSS-R has a number of advantages, including wide coverage and the ability to sense medium- and large-scale phenomena such as ocean eddies, hurricanes and tsunamis. Since 2014, about seven satellite missions have been successfully conducted and a large number of spaceborne data were recorded. Accordingly, the data have been widely used to carry out a variety of studies for a range of useful applications, and significant research outcomes have been generated. This article provides an overview of these studies with a focus on the basic methods and techniques in the retrieval of a number of geophysical parameters and the detection of several objects. The challenges and future prospects of spaceborne GNSS-R are also addressed.

show abstract

Section: Sea-surface Wind Speed Estimationmentioning

confidence: 99%

Section: Spaceborne Rainfall Detection and Rainfall Intensity Retrievalmentioning

confidence: 99%

Spaceborne GNSS Reflectometry

Han

et al. 2022

Remote Sensing

View full text Add to dashboard Cite

show abstract

“…The signal-to-noise ratio (SNR) was improved by 3 dB compared to that using the incoherent addition. In 2020, Wang and Juang [36] proposed composite delay-Doppler maps (DDMs) using simulated L1 C/A and L1C signals by the open-source GNSS-R simulator Wavpy [37] based on the configuration of the upcoming TRITON mission. The results show that the RMSE of wind speed retrieved by three composite DDM observables is approximately 1 m/s, while the state-of-art RMSE of CYGNSS wind speed products is about 1.19 m/s [38].…”

Section: Introductionmentioning

confidence: 99%

Coherent Combination of GPS III L1 C/A and L1C Signals for GNSS Reflectometry

Du,

Nan,

et al. 2024

IEEE Trans. Geosci. Remote Sensing

View full text Add to dashboard Cite

With the evolution of Global Navigation Satellite System (GNSS), more GNSS satellites and civilian signals are available for GNSS Reflectometry (GNSS-R). Developments of new onboard processing strategies can improve the observation performance of spaceborne GNSS-R. To this end, this article proposes a new processing method by coherently combining reflected Global Positioning System (GPS) III L1 C/A and L1C signals. By exploiting the additional signal component, the signalto-noise ratio of the reflected signal can be significantly improved. Moreover, taking advantage of the narrower auto-correlation function of the combined signal, the spatial resolution and the performance on geophysical applications can be significantly improved. The proposed method has been validated by processing cyclone GNSS (CYGNSS) raw intermediate frequency data including the direct and reflected signals from GPS III satellites. The results indicate that the signal-to-noise ratio (SNR) of the combined reflected waveform can be improved by ∼2 dB compared to the L1 C/A waveform. Moreover, the SNR of the combined signal can be improved more efficiently using a longer coherent integration interval compared to the L1 C/A signal. Preliminary altimetric results demonstrate a 35.3%-61.6% improvement in the ranging standard deviation, and a 22.4%-64.4% improvement in the median absolute deviation, compared to L1 C/A measurements. Additionally, the correlation coefficient between combined measurements and wind speed improves by 26.3% on average compared to L1 C/A measurements, and 45.7% for high winds. This article presents a novel GNSS-R onboard signal processing method with improved performance, which can provide a reference for the design of future GNSS-R instruments.

show abstract

“…BOC has been applied in some new signals, for example, GPS L1C and Galileo open service (OS) signals. Compared with the conventional binary phase shift keying (BPSK) [ 3 , 4 ], the BOC modulation moves signal energy away from the band center and thus realizes a high level of frequency spectrum separation. In addition, the autocorrelation peak of the BOC modulation signal is sharper than the BPSK, so it is superior to BPSK in the tracking performance and multipath mitigation capability.…”

Section: Introductionmentioning

confidence: 99%

An Unambiguous Synchronization Scheme for GNSS BOC Signals Based on Reconstructed Correlation Function

Sun

Song

et al. 2021

Sensors

View full text Add to dashboard Cite

Binary offset carrier (BOC) modulation is a new modulation method that has been gradually applied to the Global Satellite Navigation System (GNSS) in recent years. However, due to the multi-peaks in its auto-correlation function (ACF), it will incur a false lock and generate synchronization ambiguous potentially. In this paper, an unambiguous synchronization method based on a reconstructed correlation function is proposed to solve the ambiguity problem. First, through the shape code vector constructed in this paper, the general cross-correlation function (CCF) expression of the BOC modulated signal will be obtained. Based on the features of the signal correlation function, it is decomposed into a matrix form of trigonometric functions. Then, it generates two local signal waves using a specific method, then the proposed method is implemented to obtain a no-side-peak correlation function by reconstructing the cross-correlation between the received signal and the two local signals. Simulations showed that it fully eliminates the side-peak threat and significantly removes the ambiguity during the synchronization of the BOC signals. This paper also gives the improved structure of acquisition and tracking. The detailed theoretical deduction of detection probability and code tracking error is demonstrated, and the corresponding phase discrimination function is given. In terms of de-blurring ability and detection probability performance, the proposed method outperformed other conventional approaches. The tracking performance was superior to the comparison methods and the phase discrimination curve only had a zero-crossing, which successfully removed the false lock points. In addition, in multipath mitigation, it outperformed the ACF of the BOC signal, and performs as well as the autocorrelation side-peak cancellation technique (ASPeCT) for BOC(kn,n) signals.

show abstract

Retrieval of Ocean Surface Wind Speed Using Reflected BPSK/BOC Signals

Cited by 8 publications

References 26 publications

Spaceborne GNSS Reflectometry

Spaceborne GNSS Reflectometry

Coherent Combination of GPS III L1 C/A and L1C Signals for GNSS Reflectometry

An Unambiguous Synchronization Scheme for GNSS BOC Signals Based on Reconstructed Correlation Function

Contact Info

Product

Resources

About