Corner reflectors as the tie between InSAR and GNSS measurements: Case study of resource extraction in Australia

Garthwaite, Matthew C.; Lawrie, Sarah; Dawson, John; Thankappan, Medhavy

doi:10.5270/fringe2015.pp60

Cited by 6 publications

(5 citation statements)

References 8 publications

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“…These study results match better with CR9's velocity results than CR8's, confirming the assumption of a more accurate estimate in descending path than in ascending path. The maximum offset is indeed obtained on a short time interval in ascending images (2017-10-01/2017- [10][11][12][13][14][15][16][17][18][19]. The pairs with the smallest velocity uncertainty are obtained with CR9 (2017-09-30/2018-07-09 and 2017-11-17/2018-07-15), since they represent the longest time intervals.…”

Section: Dates Time Interval (D) Velocity (Cm/d) Direction Differencementioning

confidence: 89%

Integration of Corner Reflectors for the Monitoring of Mountain Glacier Areas with Sentinel-1 Time Series

et al. 2019

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Glacier flow and slope instabilities in Alpine mountain areas represent a hazard issue. Sentinel-1 satellites provide regular Synthetic Aperture Radar (SAR) acquisitions that are potentially useful to monitor these areas, but they can be affected by temporal decorrelation due to rapid changes in the surface. The application of interferometric synthetic aperture radar (InSAR) therefore seems difficult due to loss of coherence. On the other hand, Corner Reflectors (CR) can be used as coherent targets in SAR images for accurate displacement measurement thanks to their strong backscattering property and temporal stability. The use of CRs in multi-temporal InSAR analysis in Alpine mountain areas can thus be beneficial. In this study, we present a comparison between triangular and rectangular CRs, based on Radar Cross Section (RCS) measurements in an anechoic chamber and on long-term experiments over the Argentière glacier and the surrounding slopes and moraine. The visibility in both summer and winter of 10 CRs installed on the test site was investigated. As this area is exposed to heavy precipitation including snow falls, two perforated CRs were tested. The amplitude stability and the phase error of each CR were estimated. A precise tracking of two CRs installed at the glacier surface was also able to measure the displacement of the Argentière glacier, giving results close to previous GPS measurements. Furthermore, a Persistent Scatterer Interferometry (PSI) study was conducted, using the most stable CR as reference point to estimate slope instabilities, which led to the identification of an area corresponding to a tectonic fault called “Faille de l’angle”. The precise absolute locations of the CRs were successfully estimated and PS heights were compared with a LiDAR-based (Light Detection And Ranging) digital elevation model (DEM) and GPS measurements.

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Section: Dates Time Interval (D) Velocity (Cm/d) Direction Differencementioning

confidence: 89%

Integration of Corner Reflectors for the Monitoring of Mountain Glacier Areas with Sentinel-1 Time Series

et al. 2019

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“…The theoretical radar cross section (RCS), often denoted as σ T , of a triangular trihedral corner reflector that is significantly larger than the SAR wavelength, is a function of its size [16]…”

Section: A Review Of Amplitude and Phase Of A Single Corner Reflectormentioning

confidence: 99%

Novel Corner-Reflector Array Application in Essential Infrastructure Monitoring

Kelevitz

Wright

Hooper

et al. 2022

IEEE Trans. Geosci. Remote Sensing

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High precision monitoring of infrastructure using 1 artificial reflectors is possible with freely available Sentinel-1 2 data, but large reflectors are needed. We find that a triangular 3 trihedral corner reflector should typically have at least 1 m inner 4 leg length. 5 As such large reflectors are often not feasible for use in urban 6 areas for essential infrastructure monitoring, we designed a 7 multiple corner-reflector array to replace a single corner reflector 8 with an inner leg length of 1 m. In this case, we use four reflectors 9 where each of them is a truncated triangular trihedral with an 10 inner leg length of 0.33 m. We measured InSAR amplitude, phase 11 and coherence of this reflector array with various configurations 12 of alignments of the array. We find that as long as great care 13 is taken in the relative positioning of the four corner reflectors, 14 so that they constructively interfere, each horizontal or vertical 15 configuration provides the expected amplitude, coherence and 16 phase stability.17Applications of multiple small corner reflectors in urban 18 areas range from essential infrastructure monitoring (e.g bridges, 19 overpasses, tunnel constructions), through assessment of struc-20 tural health of buildings, to monitoring highway and railway 21 embankments. We show that the multiple corner array works 22 when placed in a single InSAR resolution cell, but depending on 23 the application, the number and projection of corner reflectors 24 can be varied, as long as sufficient signal-to-clutter ratio is 25 achieved in the area of interest. 26 Index Terms-Corner Reflectors, InSAR, Infrastructure mon-27 itoring 28 I. INTRODUCTION 29 O UR ever-expanding structural infrastructure is in con-30 stant need of monitoring and maintenance due to damage 31 from regular use and exposure to natural processes. It is near-32 impossible to manually inspect all bridges, railways, highways, 33 and other essential infrastructure to predict and avoid failures 34 that might result in loss of life and great economic losses. 35 Recent advances in various remote sensing methods have 36 improved our capabilities to monitor large areas with various 37 techniques of different temporal and spatial resolutions.38 In particular, Interferometric Synthetic Aperture Radar (In-39 SAR) is being widely used for ground motion detection for 40 various applications ranging from world-wide natural haz-41 ard monitoring (e.g. [1]), and early warning (e.g. [2], [3]) 42 through nation-wide infrastructure and land observation (e.g.43 [4], [5]) to small-scale studies of local deformations (e.g.

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“…Literatürde, köşe reflektör geometri parametreleri ve PSInSAR tekniğine katkılarıyla ilgili yayınlara daha sık olarak rastlanılmaktadır [12][13][14][15][16][17][18][19][20]. Köşe reflektörler uydu geçiş güzergâhına uygun bir şekilde konumlandırılarak uydu sinyallerini geri yansıtma temeli üzerine kurgulanmıştır (Şekil 1).…”

Section: Anahtar Kelimeler: Deformasyon Insar Köşe Reflektör (Cr) Mad...unclassified

“…Köşe reflektörler uydu geçiş güzergâhına uygun bir şekilde konumlandırılarak uydu sinyallerini geri yansıtma temeli üzerine kurgulanmıştır (Şekil 1). Köşe yansıtıcı içeren bir çözünürlük hücresinden gelen sinyal-gürültü oranı, doğal saçıcılar içeren bir çözünürlük hücresinden çok daha büyük olacaktır [14].…”

Section: Anahtar Kelimeler: Deformasyon Insar Köşe Reflektör (Cr) Mad...unclassified

Maden Sahalarında Köşe Reflektör (CR) Tesisi ve Sabit Saçıcı (PS) Kontrolü

POYRAZ

Gül

2022

International Journal of Innovative Engineering Applications

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Maden sahalarındaki deformasyonlar son zamanlarda, klasik yöntemlerin (GNSS alıcıları, Geometrik Nivelman, Yersel Lidar ve İHA Fotogrametresi vb.) alternatifi olarak ortaya çıkmaya başlayan uydu SAR tabanlı yöntemler ile izlenmeye başlanmıştır. Bu yöntemin en önemli avantajı, oldukça geniş alanların, alansal olarak uzaktan izlenebiliyor olmasıdır. Buna rağmen yöntem, bazı dezavantajlar da içermektedir. Bunlardan ilki; deformasyonların sadece uydu bakış doğrultusu yönünde (LOS) belirlenebiliyor olması, ikincisi ise maden kazı faaliyetlerinin bulunduğu lokasyonlarda topoğrafyanın sürekli değişimine bağlı olarak eşlenik yansıtıcı yüzey bulunamamasıdır. Bu çalışma kapsamında, Kangal Termik Santral Elektrik Üretim A.Ş.’nin Kalburçayırı ve Hamal Kömür sahalarında sabit saçıcı (PS) olmayan lokasyonlara, köşe reflektörler (CR) yerleştirilerek PS takibi amaçlanmıştır. Sentinel-1A/B uyduları vasıtası ile saha takip edilerek daha önce PS üretilemeyen lokasyonlarda CR tesisi ile oluşan yeni PS’ler başarı ile gözlemlenmiştir. Sonuçlar bize göstermiştir ki; yeterince PS üretilemeyen veya hiç görülmeyen lokasyonlara köşe reflektör yerleştirilmesi, PS sayısını ve kalitesini olumlu yönde artırmaktadır.

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Corner reflectors as the tie between InSAR and GNSS measurements: Case study of resource extraction in Australia

Cited by 6 publications

References 8 publications

Integration of Corner Reflectors for the Monitoring of Mountain Glacier Areas with Sentinel-1 Time Series

Integration of Corner Reflectors for the Monitoring of Mountain Glacier Areas with Sentinel-1 Time Series

Novel Corner-Reflector Array Application in Essential Infrastructure Monitoring

Maden Sahalarında Köşe Reflektör (CR) Tesisi ve Sabit Saçıcı (PS) Kontrolü

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