Masanobu Shimada

Tokyo Denki University · School of Science and Engineering

InSAR time series analysis has become a major tool for nationwide land deformation monitoring. Sentinel-1 SAR data have enabled us to measure and monitor ground deformation globally with high accuracy and resolution through InSAR time series analysis, due to its constant and frequent global coverage and open data policy since 2014. Although several...

Recently, it has been shown that the long penetrating polarimetric L-band ALOS is very promising for boreal and subarctic peatland mapping and monitoring. The unique information provided by the Touzi decomposition, and the dominant-scattering-type phase in particular, on peatland subsurface water flow permits an enhanced discrimination of bogs from...

PALSAR2 polarimetric distortion matrix is measured using corner reflectors deployed in the Amazonian forest. The Amazonian forest near the geomagnetic equator provides ideal sites for the assessment of L-band PALSAR2 antenna parameters, at free Faraday rotation. Corner reflectors (CRs) deployed at free Faraday rotation provide accurate estimation o...

During the 2016 Kumamoto Earthquake, many special belt-like subsidences called “grabens” occurred in the Aso Caldera, and houses were severely damaged. According to the measurement results of SAR, a horizontal displacement of 2 to 3 m was generated in the area where the grabens occurred. A lake was formed in this area around 9,000 years ago. A soil...

Satellite synthetic aperture radar (SAR) signals are affected by the Earth's ionosphere when the signals travel through the ionosphere. We first analyze the impact of ionospheric variation on the coseismic deformation results derived from interferometric SAR (InSAR) for the 2010 Maule, Chile, earthquake. We then jointly invert leveling, GPS and InS...

In this study, an automatic change detection method for near real-time (NRT) forest monitoring in tropical regions is described. L-band ALOS-2/PALSAR-2 ScanSAR HH, HV, and HH/HV ratio were used to detect various deforestation stages based on their different radar scattering characteristics. The three main stages considered in this approach were as...

The terrestrial forest carbon pool is poorly quantified, in particular in regions with low forest inventory capacity. By combining multiple satellite observations of synthetic aperture radar (SAR) backscatter around the year 2010, we generated a global, spatially explicit dataset of above-ground live biomass (AGB; dry mass) stored in forests with a...

Many grabens, which are special and strange, belt-like subsidences, formed in the caldera of the Aso Volcano during the 2016 Kumamoto Earthquake. These grabens caused severe damage to houses, roads, water and sewage pipes, rice fields, and river dikes. The authors conducted various site investigations, soil tests and analyses to determine the mecha...

Abstract The cloud-free, wide-swath, day-and-night observation capability of synthetic aperture radar (SAR) has an important role in rapid landslide monitoring to reduce economic and human losses. Although interferometric SAR (InSAR) analysis is widely used to monitor landslides, it is difficult to use that for rapid landslide detection in mountain...

We present detailed maps of local-scale 3D deformation preceding the 2018 phreatic eruption at Iwo-yama volcano (south of Kyushu Island, Japan), using a combination of airborne and spaceborne Interferometric Synthetic Aperture Radar (InSAR) data. The 3D and 2.5D deformation maps obtained at different periods allow us to successfully track their spa...

The terrestrial forest carbon pool is poorly quantified, in particular in regions with low forest inventory capacity. By combining multiple satellite observations of synthetic aperture radar (SAR) backscatter around the year 2010, we generated a global, spatially explicit dataset of above-ground forest biomass (dry mass, AGB) with a spatial resolut...

Compact-hybrid SAR (CP) is a dual-polarization (dual-pol) SAR mode that transmits a circular polarization (CirP) and measures the received signal at the horizontal and vertical antenna polarization. It is now admitted that the actual SAR technology does not permit the generation of a perfectly CirP and this may significantly affect CP radiometric a...

This study investigated a method of flood detection in built-up areas by L-band synthetic aperture radar (SAR) images, using interferometric phase statistics instead of the widely used coherence. Simulation and actual SAR data analysis showed that phase statistics are more accurate than coherence is, especially when there are many point-like scatte...

Insufficient knowledge about spatial-temporal forest heterogeneities in the tropics is a major impediment to better estimation of carbon storage and prevention of forest loss by remote sensing. Seasonality induced fluctuations can severely impede the reliability of synthetic aperture radar (SAR) applications like forest classification, deforestatio...

Rapid detection of flood areas in all weather conditions is needed for monitoring and mitigating flood disasters. In this paper, we investigated flood area detection using L-band synthetic aperture radar data acquired by the Phased-Array-type L-band Synthetic Aperture Radar-2 (PALSAR-2) aboard the Advanced Land Observing Satellite-2 during the 2015...

Observational evidence that L-band backscatter measurements are distorted by Faraday rotation (FR) is presented using match-ups consisting of the phased-array type L-band synthetic aperture radar-2 (PALSAR-2) data, scatterometer winds, and FR estimated from total electron contents (TEC) and magnetic fields. Investigating these data reveals that the...

This study presents a new global baseline of mangrove extent for 2010 and has been released as the first output of the Global Mangrove Watch (GMW) initiative. This is the first study to apply a globally consistent and automated method for mapping mangroves, identifying a global extent of 137,600 km 2 . The overall accuracy for mangrove extent was 9...

Recounts the career and contributions of Wolfgang-Martin Boerner.

In this paper, we demonstrated the possibility of performing land use and land cover (LULC) classification over a wide area by an L-band polarimetric synthetic aperture radar (SAR). In previous studies, there has been scant LULC classification by polarimetric SAR data over a wide area. We used satellite-based SAR data with an area of ca. 320 000 km...

Polarimetric characteristics of early-stage deforestation areas were examined with L-band synthetic aperture radar (SAR) to develop a forest early warning system. Time series of PALSAR-2/ScanSAR data and Landsat data were used to examine the differences in detection timing of deforestation in the most active deforestation sites in Peru and Brazil....

The Lena River in Russia at its intersection with the Arctic Ocean is subject to spring floods such as those caused by ice jams. In such cases, snowmelt occurs at lower latitudes and river water freezes at higher latitudes. That snowmelt is blocked by the frozen river water, which induces ice-jam floods every year. Full-polarimetric parameters obta...

See http://ieeexplore.ieee.org/document/8194893/ . In this paper, the authors propose a novel radio frequency interference (RFI) detection and removal method for a synthetic aperture radar (SAR). The proposed method is exclusively sensitive to a pulse-like signal that is temporally transmitted in wide bandwidth. The bandwidth of the RFI is supposed...

This letter closes a special stream consisting of selected papers from the fifth Asia-Pacific Conference on Synthetic Aperture Radar in 2015 (APSAR 2015). The latest research results and outcomes from APSAR 2015, particularly on the synthetic aperture radar (SAR) systems/subsystems design, data processing techniques, and various SAR applications in...

At radar frequencies below 2 GHz, the mismatch between the 5 to 15 cm sensing depth of classical time domain reflectometry (TDR) probe soil moisture measurements and the radar penetration depth can easily lead to unreliable in situ data. Accurate quantitative measurements of soil water contents at various depths by classical methods are cumbersome...

A polarimetric ground-based radar (GB-radar) system operated in the L-band has been developed. The frequency range of GB-radar is 1.215 to 1.3 GHz, which is the same as that of Japanese satellite-borne SAR, PALSAR-2 (Phased Array type L-band Synthetic Aperture Radar), and Japanese L-band air-borne radar, i.e., Pi-SAR-L2 (Polarimetric and Interferom...

This paper reports the validation results of burst misalignment for ScanSAR-ScanSAR interferometry of the Phased Array-type L-band Synthetic Aperture Radar-2 (PALSAR-2) aboard the Advanced Land Observing Satellite-2 (ALOS-2, "DAICHI-2"). After the internal software modification on 8 February 2015, ALOS-2 ScanSAR observation mode archives have been...

The Advanced Land Observing Satellite-2 (ALOS-2, "DAICHI-2") has been observing Nepal with the Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) in response to an emergency request from Sentinel Asia related to the Mw 7.8 Gorkha earthquake on April 25, 2015. PALSAR-2 successfully detected not only avalanches and local crustal displacem...

Rapid and all-weather detection of flood areas is needed to monitor and mitigate flood disasters. This study addressed flood area detection using ALOS-2 PALSAR-2 data acquired during the 2015 heavy rainfall disaster in the Kanto and Tohoku area of Japan. We propose an approach to flood area detection by thresholding amplitude and interferometric co...

Land subsidence, which is a threat to some large cities in Indonesia, is a very important issues for the Indonesian government to address. Thus, the land subsidence monitoring methods that can take quick, continuous and highly accurate measurements over large areas at a reasonable cost are necessary. Due to the limitation of SAR satellites life spa...

The Jakarta province proposed the Jakarta Giant Sea Wall as the waterfront city for the new urban settlement zone and the deep seaport for the new economic zone along the coastal areas at northern Jakarta. This letter investigated land deformation at 11 watersheds of the West Java Mega Urban Region using the persistent scatterer interferometry tech...

Pi-SAR-L2 full polarimetic data observed in four different observational directions over a landslide area on Izu Oshima Island, induced by Typhoon Wipha on 16 October 2013, were analyzed to clarify the most appropriate L-band full polarimetric parameters and observational direction to detect a landslide area. Japanese airborne Pi-SAR-L2 and PiSAR-L...

This study examines the potential of airborne PiSAR-L2 data for estimating forest carbon stocks in central Sumatra. Polarimetric interferometric Synthetic Aperture Radar L-band-2 (PiSAR-L2) is a second-generation airborne sensor developed by JAXA. We acquired full polarimetric data at a fine spatial resolution of 2.5 m during the PiSAR-L2 flight ca...