Urban Deformation Monitoring using Persistent Scatterer Interferometry and SAR tomography

This book focuses on remote sensing for urban deformation monitoring. In particular, it highlights how deformation monitoring in urban areas can be carried out using Persistent Scatterer Interferometry (PSI) and Synthetic Aperture Radar (SAR) Tomography (TomoSAR). Several contributions show the capabilities of Interferometric SAR (InSAR) and PSI techniques for urban deformation monitoring. Some of them show the advantages of TomoSAR in un-mixing multiple scatterers for urban mapping and monitoring. This book is dedicated to the technical and scientific community interested in urban applications. It is useful for choosing the appropriate technique and gaining an assessment of the expected performance. The book will also be useful to researchers, as it provides information on the state-of-the-art and new trends in this fiel

STUDY ON FLOOD INUNDATION IN PEKALONGAN, CENTRAL JAVA

Tidal flood or ‘rob’ is a serious problem in many coastal areas in Indonesia, including Pekalongan in the northern coast of Java island. This study aimed to simulate the flood inundation area for different scenarios of sea level rise, also to investigate the possibility of land subsidence that may further aggravate the problem of flooding in Pekalongan. In this study, the MIKE-21 model was used to simulate and predict the flood inundation area. Tidal data were generated from the Tide Model Drive (TMD). The tidal flood simulations were carried out for three different scenarios of sea level rise: 1) current situation, 2) next 50 years, assuming no sea level rise, and 3) next 50 years, assuming 50 cm of sea level rise. Based on the results, the ranges of water level rise in Pekalongan for each scenario were 0.23-1.27 m, 0.36-1.38 m, and 0.65-1.53 m, respectively. Meanwhile, ground displacement maps were derived from the ALOS/PALSAR data using Differential Interferometric Synthetic Aperture Radar (D-InSAR) technique. Twelve level 1.0 images of ALOS/PALSAR data acquired in ascending mode during 2008 to 2009 were collected and processed in time-series analyses. In total, 11 pairs of interferogram were produced by taking the first image in 2008 as the master image. The results showed that the average of land subsidence rate in Pekalongan city was 3 cm/year, and the subsidence mainly occurred in the western part of the city

Minimizing the residual topography effect on interferograms to improve DInSAR results: estimating land subsidence in Port-Said City, Egypt

The accurate detection of land subsidence rates in urban areas is important to identify damage-prone areas and provide decision-makers with useful information. Meanwhile, no precise measurements of land subsidence have been undertaken within the coastal Port-Said City in Egypt to evaluate its hazard in relationship to sea-level rise. In order to address this shortcoming, this work introduces and evaluates a methodology that substantially improves small subsidence rate estimations in an urban setting. Eight ALOS/PALSAR-1 scenes were used to estimate the land subsidence rates in Port-Said City, using the Small BAse line Subset (SBAS) DInSAR technique. A stereo pair of ALOS/PRISM was used to generate an accurate DEM to minimize the residual topography effect on the generated interferograms. A total of 347 well distributed ground control points (GCP) were collected in Port-Said City using the leveling instrument to calibrate the generated DEM. Moreover, the eight PALSAR scenes were co-registered using 50 well-distributed GCPs and used to generate 22 interferogram pairs. These PALSAR interferograms were subsequently filtered and used together with the coherence data to calculate the phase unwrapping. The phase-unwrapped interferogram-pairs were then evaluated to discard four interferograms that were affected by phase jumps and phase ramps. Results confirmed that using an accurate DEM (ALOS/PRISM) was essential for accurately detecting small deformations. The vertical displacement rate during the investigated period (2007–2010) was estimated to be −28 mm. The results further indicate that the northern area of Port-Said City has been subjected to higher land subsidence rates compared to the southern area. Such land subsidence rates might induce significant environmental changes with respect to sea-level rise

InSAR reveals land deformation at Guangzhou and Foshan, China between 2011 and 2017 with COSMO-SkyMed data

Subsidence from groundwater extraction and underground tunnel excavation has been known for more than a decade in Guangzhou and Foshan, but past studies have only monitored the subsidence patterns as far as 2011 using InSAR. In this study, the deformation occurring during the most recent time-period between 2011 and 2017 has been measured using COSMO-SkyMed (CSK) to understand if changes in temporal and spatial patterns of subsidence rates occurred. Using InSAR time-series analysis (TS-InSAR), we found that significant surface displacement rates occurred in the study area varying from -35 mm/year (subsidence) to 10 mm/year (uplift). The 2011-2017 TS-InSAR results were compared to two separate TS-InSAR analyses (2011-2013, and 2013-2017). Our CSK TS-InSAR results are in broad agreement with previous ENVISAT results and levelling data, strengthening our conclusion that localised subsidence phenomena occurs at different locations in Guangzhou and Foshan. A comparison between temporal and spatial patterns of deformations from our TS-InSAR measurements and different land use types in Guangzhou shows that there is no clear relationship between them. Many local scale deformation zones have been identified related to different phenomena. The majority of deformations is related to excessive groundwater extraction for agricultural and industrial purposes but subsidence in areas of subway construction also occurred. Furthermore, a detailed analysis on the sinkhole collapse in early 2018 has been conducted, suggesting that surface loading may be a controlling factor of the subsidence, especially along the road and highway. Roads and highways with similar subsidence phenomenon are identified. Continuous monitoring of the deforming areas identified by our analysis is important to measure the magnitude and spatial pattern of the evolving deformations in order to minimise the risk and hazards of land subsidence

Computing the relative land subsidence at Venice, Italy, over the last fifty years

Abstract: Land subsidence causes various damages to the infrastructures and cultural heritage in many cities worldwide. Urban flooding is one of the main consequences of land subsidence in coastal cities, where it is exacerbated by sea-level rise accompanying global climate change, but also in inland metropolitan areas such as Mexico City, where subsidence zones are increasingly flooded following intense rainstorms. The subsidence of Venice, one of the most beautiful and famous cities in the world, is well known not for the magnitude of subsidence but because subsidence has seriously compromised the heritage and the safety of the city in relation to its small elevation above the sea. The storm that flooded the historical center of Venice on November 4, 1966 dramatically revealed its fragility with respect to land subsidence and sea-level rise, or the Relative Land Subsidence (RLS), i.e. land movement with respect to sea-level changes. That event signaled the beginning of a systematic monitoring of the loss in elevation of the ground surface of Venice with respect to the mean level of the Northern Adriatic (NA) Sea. Tide gauge measurements, available from the beginning of the last century, have been supplied historically by levelling and more recently by Synthetic Aperture Radar (SAR)-based Interferometry. On the occasion of the 50th anniversary of the 1966 flood event, we quantify the RLS experienced by the city over these last five decades with a detail never achieved before. The computation of the loss of elevation has been obtained by processing and superposing the results of levelling surveys carried out in 1961, 1969, 1973, and 1993, together with the results of Interferometric processing of SAR images acquired from satellites: 1993 to 2002 by ERS-1/2, 2003 and 2010 by ENVISAT, 2008 to 2013 by TerraSAR-X, and 2012 to 2016 by COSMO-SkyMED. The records from the tide gauge in Trieste, which is a city on the coast of the NA Sea close to the Alps and known to be stable, are used to evaluate the sea-level rise over the targeted time interval. The mean land velocity (v) for each analyzed period has been obtained by interpolating the original measurements using the Kriging method on a same regular 50-m grid covering the entire city. Then, cumulative land subsidence (LStot)) from 1966 to 2016 has been simulated in a GIS environment by summing the partial land subsidence over the various periods covered by the levelling and SAR surveys. The results point out that in the Venice historical center between 1966 and 2016: • Land subsidence rate has been more variable in space but less variable over time than the changes of the NA mean sea level; • average subsidence has amounted to 0.8 mm/yr and the average NA msl rise to 1.9 mm/yr; • minimum and maximum cumulative subsidence has totalled 8 mm and 93 mm, respectively; and • maximum loss of elevation with respect to the NA msl (i.e. RLS) has been 190 mm. RLS has produced a tangible effect on the Venice historical center revealed by the continuous increase in frequency of the flooding events, locally called "acqua alta". In the next years, any further loss of elevation with respect to the mean sea level, even a few mm, will threaten the city’s survival with severe social and environmental impacts. Considering the present average land subsidence of Venice and sea level rise of the NA (i.e. both about 1.2 mm/yr), an additional loss of elevation of about 190 mm will likely occur by 2100. Actually, according to conservative and pessimistic IPCC scenarios, the sea-level accompanying global climate change is expected to rise from 32 to 56 cm. Therefore, the outcomes from this study should be properly taken in account for the planning of effective interventions for the mitigation of climate changes to maintain the historical center of this unique city

Computing the relative land subsidence at Venice, Italy, over the last fifty years

Abstract: Land subsidence causes various damages to the infrastructures and cultural heritage in many cities worldwide. Urban flooding is one of the main consequences of land subsidence in coastal cities, where it is exacerbated by sea-level rise accompanying global climate change, but also in inland metropolitan areas such as Mexico City, where subsidence zones are increasingly flooded following intense rainstorms. The subsidence of Venice, one of the most beautiful and famous cities in the world, is well known not for the magnitude of subsidence but because subsidence has seriously compromised the heritage and the safety of the city in relation to its small elevation above the sea. The storm that flooded the historical center of Venice on November 4, 1966 dramatically revealed its fragility with respect to land subsidence and sea-level rise, or the Relative Land Subsidence (RLS), i.e. land movement with respect to sea-level changes. That event signaled the beginning of a systematic monitoring of the loss in elevation of the ground surface of Venice with respect to the mean level of the Northern Adriatic (NA) Sea. Tide gauge measurements, available from the beginning of the last century, have been supplied historically by levelling and more recently by Synthetic Aperture Radar (SAR)-based Interferometry. On the occasion of the 50th anniversary of the 1966 flood event, we quantify the RLS experienced by the city over these last five decades with a detail never achieved before. The computation of the loss of elevation has been obtained by processing and superposing the results of levelling surveys carried out in 1961, 1969, 1973, and 1993, together with the results of Interferometric processing of SAR images acquired from satellites: 1993 to 2002 by ERS-1/2, 2003 and 2010 by ENVISAT, 2008 to 2013 by TerraSAR-X, and 2012 to 2016 by COSMO-SkyMED. The records from the tide gauge in Trieste, which is a city on the coast of the NA Sea close to the Alps and known to be stable, are used to evaluate the sea-level rise over the targeted time interval. The mean land velocity (v) for each analyzed period has been obtained by interpolating the original measurements using the Kriging method on a same regular 50-m grid covering the entire city. Then, cumulative land subsidence (LStot)) from 1966 to 2016 has been simulated in a GIS environment by summing the partial land subsidence over the various periods covered by the levelling and SAR surveys. The results point out that in the Venice historical center between 1966 and 2016: • Land subsidence rate has been more variable in space but less variable over time than the changes of the NA mean sea level; • average subsidence has amounted to 0.8 mm/yr and the average NA msl rise to 1.9 mm/yr; • minimum and maximum cumulative subsidence has totalled 8 mm and 93 mm, respectively; and • maximum loss of elevation with respect to the NA msl (i.e. RLS) has been 190 mm. RLS has produced a tangible effect on the Venice historical center revealed by the continuous increase in frequency of the flooding events, locally called "acqua alta". In the next years, any further loss of elevation with respect to the mean sea level, even a few mm, will threaten the city’s survival with severe social and environmental impacts. Considering the present average land subsidence of Venice and sea level rise of the NA (i.e. both about 1.2 mm/yr), an additional loss of elevation of about 190 mm will likely occur by 2100. Actually, according to conservative and pessimistic IPCC scenarios, the sea-level accompanying global climate change is expected to rise from 32 to 56 cm. Therefore, the outcomes from this study should be properly taken in account for the planning of effective interventions for the mitigation of climate changes to maintain the historical center of this unique city

Monitoring von Hangbewegungen mit InSAR Techniken im Gebiet Ciloto, Indonesien

In this doctoral thesis, the InSAR techniques are applied to detect the ground movement phenomenon and to assess the InSAR result geometrically in the Ciloto area, Indonesia. Mainly, one of those techniques, the SB-SDFP algorithm, overcomes the limitations of conventional InSAR in monitoring rural and agricultural areas and can observe extremely slow landslides. The InSAR strategy is positively known as a promising option to detect and quantify the kinematics of active landslides on a large areal scale. To minimize the bias of the InSAR displacement result, the correction of the tropospheric phase delay was carried out in a first step. This procedure is demonstrated in experiments both in the small study area in Ciloto and in a larger area. The latter is an area located in Northern Baja California, Mexico and is dominated by tectonic activity as well as groundwater-induced subsidence. A detailed investigation of the slope movement's behavior in the Ciloto district was conducted utilizing multi-temporal and multi-band SAR data from ERS1/2 (1996-1999), ALOS PALSAR (2007-2009) and Sentinel-1 (2014-2018) satellites. The region was successfully identified as a permanent active landslide prone area, especially in the vicinity of the Puncak Pass and Puncak Highway. The full 3D velocity field and the displacement time series were estimated using the inversion model. The velocity rate was classified from extremely slow to slow movement. To comprehend the landslide's behavior, a further examination of the relationship between InSAR results and physical characteristics of the area was carried out. For the long period of a slow-moving landslide, the relationship between precipitation and displacement trend shows a weak correlation. It is concluded that the extremely slow to slow deformation is not directly influenced by the rainfall intensity, yet it effectuates the subsurface and the groundwater flow. The run-off process with rainfall exceeding a soil's infiltration capacity was suspected as the main driver of the slow ground movement phenomenon. However, when analyzing rapid and extremely rapid landslide events at Puncak Pass, a significant increase in the correlation coefficient between precipitation and displacement rate could be observed.In dieser Doktorarbeit wird die Anwendung von erweiterten Verarbeitungsstrategien von InSAR Daten zur Erkennung und geometrischen Bewertung der Bodenbewegungen im Ciloto - Indonesien dargestellt. Dieser Ansatz überwindet die Beschränkungen konventioneller SAR-Interferometrie und ermöglicht sowohl ein kontinuierliches Monitoring dieses landwirtschaftich geprägten Gebietes als auch die Erfassung extrem langsamer Hangrutschungen. Um eine Verzerrung der InSAR Deformationsergebnisse zu minimieren, wurde zunächst eine Korrektur der troposphärischen Phase durchgeführt. Diese neuartige Strategie wird sowohl im Forschungsgebiet Ciloto als auch an einem größeren Gebiet demonstriert. Bei letzterem handelt es sich um einen Küstenstreifen im nördlichen Niederkalifornien, Mexiko, welcher durch hohe tektonische Aktivität und grundwasserinduzierte Landsetzungen charakterisiert ist. Die detaillierte Untersuchung des Verhaltens von Hangrutschungen im Ciloto erfolgte durch die Verarbeitung multi-temporaler SAR-Daten unter Nutzung verschiedener Frequenzbänder, darunter ESR1/2 (1996-1999), ALOS PALSAR (2007-2009) und Sentinel-1 (2014-2018) Daten. Die Region konnte erfolgreich als permanent aktives Hangrutschungsgebiet identifiziert werden, wobei der Puncak Pass und der Puncak Highway ein erhöhtes Gefahrenpotential aufweisen. Ein 3D- Geschwindig-keitsfeld der Deformation und die zugehörigen Zeitreihen wurden mit dem Inversionsmodell berechnet. Die Geschwindigkeitsrate wurde als langsam bis extrem langsam klassifiziert. Um das dynamische Verhalten der Hangrutschung zu verstehen wurde, in einer weiteren Untersuchung die Beziehung zwischen dem InSAR-Ergebnis und den physikalischen Begebenheiten im Forschungsgebiet analysiert. Es wird der Schluss gezogen, dass die langsame bis extrem langsame Verformung nicht direkt von der Niederschlagsintensität beeinflusst wird, diese sich aber auf den Untergrund und die Grundwasserströmung auswirkt. Es wird vermutet, dass der Oberflächenablauf, welcher die Infiltrationskapazität des Bodens übersteigt, ausschlaggebend für das Phänomen der langsamen Bodenbewegung ist. Für die schnellen und extrem schnellen Hangrutschungen jedoch konnte eine signifikante Erhöhung des Korrelationskoeffizienten zwischen Niederschlag und Verschiebungsrate bei Untersuchungen der Hangrutschung am Puncak-Pass nachgewiesen werden

Multi-sensor synergy for persistent scatterer interferometry based ground subsidence monitoring

Ground subsidence is a common phenomenon which causes disturbances and damages on the Earth’s surface. Especially in urban areas, it poses risk to life and property. Establishing solutions for damage prevention requires knowledge of subsidence behavior over time and space, which entails the collection of geospatial information. The present work investigates the ground surface dynamics over a field of deep mining in Sondershausen, Germany based on multi-temporal Synthetic Aperture Radar (SAR) images. Deformation patterns are extracted by means of Persistent Scatterer Interferometry (PSI), a technique that exploits the spatio-temporal characteristics of interferometric signatures from persistent scatterers. Since the impact of subsidence on surface structures varies spatially, high-risk areas can only be identified when the subsidence profile is known. To model the geometry of the subsidence bowl, the present study extends the extracted point information to a surface of estimations by interpolation. Furthermore, by the synergistic usage of PS estimations from different satellite sensors, this research addresses the problem of undersampling in critical areas, which is a common limitation of the PSI approach. The methodology developed here estimates missing information, i.e. refines the initial model, by deformation map of a different sensor covering a different time interval. In order to extend the period of monitoring as well as to improve the spatial and temporal sampling, the ground subsidence in Sondershausen is monitored with a multi-sensor SAR dataset. The C- and L-band acquisitions of the sensors ERS-1/2 (1995–2005), Envisat-ASAR (2004–2010) and ALOS-PALSAR (2007–2010) are used to derive 15 years of subsidence information at the location of persistent scatterers. From a temporal viewpoint, the obtained deformation maps indicate a non-linearly decreasing trend of ground subsidence, which is consistent with the backfilling history of the mine. From a spatial viewpoint, the results suggest one major subsidence trough located in the urban area of Sondershausen and a minor one found in the nearby village of Großfurra. The PSI deformation maps and models are validated in reference to the available leveling measurements covering the site in Sondershausen. In general, the validation results suggest a good agreement between the PSI and surveying models with the normalized root-mean-square error (RMSE) lower than 0.11. However, some significant deviations of ERS estimations are also found for a critical region. In this area the absence of persistent scatterers contributes largely to the observed differences. Consequently, the spatial refinement by synergy is applied to this region. The integration of points from ASAR or PALSAR deformation maps result in an improvement in the modeled geometry of the subsidence trough. With this improvement the RMSE calculated for the ERS model is decreased from 0.061 to 0.054. The application demonstrates the synergistic potential of multi-sensor PSI analysis to improve the interpretation of ground subsidence characteristics and, thus, to increase the confidence of risk assessment.Absenkungen des Bodens stellen ein häufig auftretendes Phänomen dar. Diese Bodensenkungen verursachen Störungen und Schäden an der Erdoberfläche, die, insbesondere in urbanen Gebieten, Menschenleben gefährden und die bestehende Infrastruktur beschädigen können. Die Entwicklung von Lösungsansätzen zur Vermeidung von Schäden erfordert fundierte Kenntnisse über die räumliche und zeitliche Verteilung der Absenkungsbewegungen. Im Rahmen der vorliegenden Studie wurde die Dynamik der Bodenbewegungen über dem Salzabbaugebiet Sondershausen in Deutschland mittels Zeitserien von Synthetic Aperture Radar (SAR)-Aufnahmen untersucht. Zur Analyse der Zeitserien wurde das Verfahren der Persistent Scatterer Interferometry (PSI) eingesetzt. Diese Methode zur Extraktion der Bodendeformation basiert auf der Auswertung räumlicher und zeitlicher Charakteristika der interferometrischen Signaturen zeitlich stabiler Punktstreuer. Zur Bestimmung von Gebieten, die von den Bodensenkungen besonders stark betroffen sind, ist eine detailliertere Ermittlung der geometrischen Eigenschaften der Absenkung nötig, da die Oberflächenstrukturen entlang des Absenkungsprofiles variieren. Aufgrund dessen wurde in der vorliegenden Studie die punktweise gewonnene Information in die Flache extrapoliert, um eine räumliche Modellierung des Absenkungsbeckens zu ermöglichen. Zur genauen Vermessung von Absenkungen mittels PSI ist eine möglichst hohe räumliche und zeitliche Abtastrate anzustreben. Diese sind bei der Untersuchung eines Gebietes mithilfe eines einzelnen Radarsensors häufig nicht gewährleistet. Im Rahmen der vorliegenden Arbeit wird ein Lösungsansatz für diese Limitation vorgestellt, welcher auf der synergetischen Verschneidung von Deformationskarten mehrerer Radarsensoren basiert. Fehlende Messwerte in der ERS-Zeitreihe werden anhand von Punktstreuern in ASAR- und PALSAR-Szenen geschätzt. Die Bodenbewegungen im Gebiet Sondershausen wurden mithilfe von Daten verschiedener Radarsensoren beobachtet, um eine verbesserte räumliche und zeitliche Abtastrate zu erzielen. Hierzu wurden Aufnahmen der C- bzw. L-Band Sensoren ERS-1/2 (1995–2005), Envisat-ASAR (2004–2010) und ALOS-PALSAR (2007–2010) auf zeitlich stabile Punktstreuer untersucht. Die zeitliche Analyse der resultierenden Deformationskarten zeigt eine nicht-lineare Abnahme der Bodenabsenkungen. Dieses Verhalten steht im Einklang mit den rezenten Verfüllungsaktivitäten in der stillgelegten Mine. Die räumliche Auswertung der Daten deutet auf ein Absenkungsbecken im Stadtgebiet von Sondershausen hin. Ein weiteres, kleineres Becken konnte um die Siedlung Großfurra identifiziert werden. Sowohl die Deformationskarten als auch die abgeleiteten Modelle wurden einer umfangreichen Validierung anhand von Nivellement-Messungen unterzogen. Die Ergebnisse zeigen generell eine gute Übereinstimmung zwischen den PSI- und Bodenmessungen mit einem root-mean-square error (RMSE) von weniger als 0,11. Nur vereinzelt kommt es zu signifikanten Abweichungen, was insbesondere auf die ERS-Ergebnisse zutrifft. Dies lässt sich durch fehlende Punktstreuer in den aktiven Absenkungsbereichen während der ERS-Messungen begründen. Durch die Integration von Punkten aus den ASAR oder PALSAR-basierenden Deformationskarten konnte die Geometrie der Absenkungen verbessert werden. Der für das ERS-Modell ermittelte RMSE verringert sich auf diese Weise von 0,061 auf 0,054. Die vorliegende Anwendung zeigt das Synergiepotential multi-sensoraler Daten und Methoden verbesserten Interpretation von Bodenabsenkungen sowie zur genaueren Abschatzung und Bewertung von daraus resultierenden Risiken

Literatur Review: Perbandingan Berbagai Teknik Pemodelan Land Subsidence

Fenomena penurunan tanah atau Land Subsidence merupakan peristiwa yang dapat diidentifikasi dengan berbagai metode. Penting untuk dapat mengetahui terlebih dahulu hipotesa penyebab terjadinya penurunan tanah, diantaranya adalah disebabkan eksploitasi air bawah tanah, eksploitasi hidrokarbon, terjadinya konsolidasi tanah, akibat faktor geologi dan aktivitas tektonikReview artikel ini dilakukan dengan melakukan pencarian data pada database jurnal. Keyword yang digunakan pada pencarian artikel adalah “Land Subsidence Modeling”. Artikel yang didapatkan kemudian dibandingkan. Perbandingan dilakukan untuk mendapatkan inti dari artikel ilmiah tersebut terutama pada judul, data yang digunakan, metode pemodelan, metode pengamatan land subsidence, dan hasil penelitian.Indentifikasi Land Subsidence dapat dilakukan dengan menggunakan metode analisa kompaksi lapisan tanah dan batuan, analisa perubahan muka air bawah tanah, pengukuran GPS, Levelling dan time-series InSAR. Pemodelan terhadap fenomena Land Subsidence tidak cukup dengan hanya data geometrik dari pengukuran geodetik, tapi juga harus didukung data fisis yang berkaitan dengan penyebab Land Subsidenc

Monitoring land subsidence of airport using InSAR time-series techniques with atmospheric and orbital error corrections

Land subsidence is one of the common geological hazards worldwide and mostly caused by human activities including the construction of massive infrastructures. Large infrastructure such as airport is susceptible to land subsidence due to several factors. Therefore, monitoring of the land subsidence at airport is crucial in order to prevent undesirable loss of property and life. Remote sensing technique, especially Interferometric Synthetic Aperture Radar (InSAR) has been successfully applied to measure the surface deformation over the past few decades although atmospheric artefact and orbital errors are still a concerning issue in this measurement technique. Multi-temporal InSAR, an extension of InSAR technique, uses large sets of SAR scenes to investigate the temporal evolution of surface deformation and mitigate errors found in a single interferogram. This study investigates the long-term land subsidence of the Kuala Lumpur International Airport (KLIA), Malaysia and Singapore Changi Airport (SCA), Singapore by using two multi-temporal InSAR techniques like Small Baseline Subset (SBAS) and Multiscale InSAR Time Series (MInTS). General InSAR processing was conducted to generate interferogram using ALOS PALSAR data from 2007 until 2011. Atmospheric and orbital corrections were carried out for all interferograms using weather model, namely European Centre for Medium Range Weather Forecasting (ECMWF) and Network De-Ramping technique respectively before estimating the time series land subsidence. The results show variation of subsidence with respect to corrections (atmospheric and orbital) as well as difference between multi-temporal InSAR techniques (SBAS and MInTS) used. After applying both corrections, a subsidence ranging from 2 to 17 mm/yr was found at all the selected areas at the KLIA. Meanwhile, for SCA, a subsidence of about less than 10 mm/yr was found. Furthermore, a comparison between two techniques (SBAS and MInTS) show a difference rate of subsidence of about less than 1 mm/yr for both study area. SBAS technique shows more linear result as compared to the MInTS technique which shows slightly scattering pattern but both techniques show a similar trend of surface deformation in both study sites. No drastic deformation was observed in these two study sites and slight deformation was detected which about less than 20mm/yr for both study areas probably occurred due to several reasons including conversion of the land use from agricultural land, land reclamation process and also poor construction. This study proved that InSAR time series surface deformation measurement techniques are useful as well as capable to monitor deformation of large infrastructure such as airport and as an alternative to costly conventional ground measurement for infrastructure monitoring