Search Results - "Koyama, Christian"

Refined algorithm for forest early warning system with ALOS-2/PALSAR-2 ScanSAR data in tropical forest regions by Watanabe, Manabu, Koyama, Christian N., Hayashi, Masato, Nagatani, Izumi, Tadono, Takeo, Shimada, Masanobu

“…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…”
Get full text

Mapping the spatial-temporal variability of tropical forests by ALOS-2 L-band SAR big data analysis by Koyama, Christian N., Watanabe, Manabu, Hayashi, Masato, Ogawa, Takashi, Shimada, Masanobu

“…Insufficient knowledge about spatial-temporal forest heterogeneities in the tropics is a major impediment to better estimation of carbon storage and prevention…”
Get full text

Disaster debris estimation using high-resolution polarimetric stereo-SAR by Koyama, Christian N., Gokon, Hideomi, Jimbo, Masaru, Koshimura, Shunichi, Sato, Motoyuki

“…This paper addresses the problem of debris estimation which is one of the most important initial challenges in the wake of a disaster like the Great East Japan…”
Get full text

Early-Stage Deforestation Detection in the Tropics With L-band SAR by Watanabe, Manabu, Koyama, Christian N., Hayashi, Masato, Nagatani, Izumi, Shimada, Masanobu

“…Polarimetric characteristics of early-stage deforestation areas were examined with L-band synthetic aperture radar (SAR) to develop a forest early warning…”
Get full text

In-Situ Measurement of Soil Permittivity at Various Depths for the Calibration and Validation of Low-Frequency SAR Soil Moisture Models by Using GPR by Koyama, Christian N., Liu, Hai, Takahashi, Kazunori, Shimada, Masanobu, Watanabe, Manabu, Khuut, Tseedulam, Sato, Motoyuki

“…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…”
Get full text

Post-Earthquake Damage Inspection of Wood-Frame Buildings by a Polarimetric GB-SAR System by Liu, Hai, Koyama, Christian, Zhu, Jinfeng, Liu, Qinghuo, Sato, Motoyuki

“…Structural damage inspection after an earthquake is essential for safety assessment of the affected wood-frame buildings and for making knowledgeable decision…”
Get full text

The SARSense Campaign: Air- and Space-Borne C- and L-Band SAR for the Analysis of Soil and Plant Parameters in Agriculture by Mengen, David, Montzka, Carsten, Jagdhuber, Thomas, Fluhrer, Anke, Brogi, Cosimo, Baum, Stephani, Schüttemeyer, Dirk, Bayat, Bagher, Bogena, Heye, Coccia, Alex, Masalias, Gerard, Trinkel, Verena, Jakobi, Jannis, Jonard, François, Ma, Yueling, Mattia, Francesco, Palmisano, Davide, Rascher, Uwe, Satalino, Giuseppe, Schumacher, Maike, Koyama, Christian, Schmidt, Marius, Vereecken, Harry

“…With the upcoming L-band Synthetic Aperture Radar (SAR) satellite mission Radar Observing System for Europe L-band SAR (ROSE-L) and its integration into…”
Get full text

Comparative Analysis of the Global Forest/Non-Forest Maps Derived from SAR and Optical Sensors. Case Studies from Brazilian Amazon and Cerrado Biomes by Sano, Edson E., Rizzoli, Paola, Koyama, Christian N., Watanabe, Manabu, Adami, Marcos, Shimabukuro, Yosio E., Bayma, Gustavo, Freitas, Daniel M.

“…Global-scale forest/non-forest (FNF) maps are of crucial importance for applications like biomass estimation and deforestation monitoring. Global FNF maps…”
Get full text

Next-Generation L-Band SAR Deforestation Detection for Operational Forest Early Warning in the Tropics by Koyama, Christian N., Shimada, Masanobu, Kobayashi, Kazufumi, Hayashi, Masato, Tadono, Takeo

“…Operational deforestation detection and forest early warning is one hot topic in synthetic aperture radar (SAR) Earth observation (EO) today. Especially in…”
Get full text

Advancements in Global Forest Monitoring Research Founded on ALOS-2 Long-Term Pantropical Land Observation by Koyama, Christian N., Watanabe, Manabu, Hayashi, Masato, Shimada, Masanobu, Kobayashi, Kazufumi, Tadono, Takeo

“…Nearing 8 years in orbit, ALOS-2/PALSAR-2 has acquired the world's first long-term pantropical L-band SAR forest monitoring data archive. The unprecedented…”
Get full text

Achievements of the ALOS-2 L-Band SAR Long-Term Pantropical Forest Monitoring Mission by Koyama, Christian N., Shimada, Masanobu, Kobayashi, Kazufumi, Watanabe, Manabu, Rosenqvist, Ake, Hayashi, Masato, Yamanokuchi, Tsutomu, Tadono, Takeo

“…Forest monitoring is a prime objective for orbital synthetic aperture radar (SAR) missions. Especially in tropical regions where persistent cloud coverage…”
Get full text

Advanced Polarimetric Stereo-Sar for Tsunami Debris Estimation and Disaster Mitigation by Koyama, Christian N., Koshimura, Shunichi, Sato, Motoyuki

“…Debris estimation is one of the most important initial challenges after a disaster like the Great East Japan Earthquake and Tsunami. Reasonable estimates of…”
Get full text

Mapping Spatial-Temporal Forest Heterogeneity in the Tropical Belt by ALOS-2/PALSAR-2 Big Data Analysis by Koyama, Christian N., Watanabe, Manabu, Shimada, Masanobu

“…Insufficient knowledge about spatial-temporal forest heterogeneities in the tropics is a major impediment to better estimation of carbon storage and prevention…”
Get full text

Rainfall-Induced Changes in L-Band Backscatter Over Tropical Forests and Their Impact on Deforestation Monitoring by Koyama, Christian N., Watanabe, Manabu, Hayashi, Masato, Nagatani, Izumi, Tadono, Takeo, Shimada, Masanobu

“…One of the prime objectives for orbital civilian SARs is forest observation. Though tremendous effort has been devoted to improving applications like biomass…”
Get full text

Improving L-Band SAR Forest Monitoring by Big Data Deep Learning Based on ALOS-2 5 Years Pan-Tropical Observations by Koyama, Christian N., Watanabe, Manabu, Sano, Edson E., Hayashi, Masato, Nagatani, Izumi, Tadono, Takeo, Shimada, Masanobu

“…Forest observation is one prime objective for current and future L-band SAR missions. Despite the tremendous achievements made in the last 3 decades, the…”
Get full text

Detection and classfication of subsurface objects by polarimetric radar imaging by Koyama, Christian N., Sato, Motoyuki

“…The paper addresses the problem of subsurface object detection by polarimetric synthetic aperture radar (PolSAR) imaging. We are developing methods to detect…”
Get full text

Development of a biomass corrected soil moisture retrieval model for dual-polarization ALOS-2 data based on ALOS/PALSAR and PI-SAR-L2 observations by Koyama, Christian N., Schneider, Karl, Sato, Motoyuki

“…An empirical soil moisture retrieval model for dual-polarimetric L-band SAR imaging, the ALOS-2 standard observation, is being developed. The model, based on…”
Get full text

Full polarimetric UWB GB-SAR for damage assessment of wooden building structures by Koyama, Christian N., Iitsuka, Yasushi, Takahashi, Kazunori, Sato, Motoyuki

“…A full polarimetric ground-based SAR system for subsurface damage assessment of wooden building structures has been developed. The system is based on a…”
Get full text

The effect of precipitation and soil moisture variations on (partial) polarimetric L-band SAR backscatter in tropical forest regions by Koyama, Christian N., Watanabe, Manabu, Hayashi, Masato, Shimada, Masanobu

“…ALOS-2 ScanSAR data was used for examining the effect of precipitation and soil moisture variations on L-band forest backscatter in tropical regions…”
Get full text

Urban damage mapping using scattering mechanism investigation technique for fully polarimetric SAR data by Si-Wei Chen, Yong-Zhen Li, Xue-Song Wang, Koyama, Christian N., Sato, Motoyuki

“…Mapping of the urban damage levels with synthetic aperture radar (SAR) is still challenging. Fully polarimetric SAR (PolSAR) has the potential to identify the…”
Get full text