Christian N. Koyama

According to our database, Christian N. Koyama authored at least 31 papers between 2011 and 2023.

Collaborative distances:

• Dijkstra number of five.
• Erdős number of five.

2023

Achievements of the ALOS-2 L-Band SAR Long-Term Pantropical Forest Monitoring Mission.

Christian N. Koyama, Masanobu Shimada, Kazufumi Kobayashi, Manabu Watanabe, Ake Rosenqvist, Masato Hayashi, Tsutomu Yamanokuchi, Takeo Tadono

Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, 2023

Next-Generation L-Band SAR Deforestation Detection for Operational Forest Early Warning in the Tropics.

Christian N. Koyama, Masanobu Shimada, Kazufumi Kobayashi, Masato Hayashi, Takeo Tadono

Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, 2023

2022

Advancements in Global Forest Monitoring Research Founded on ALOS-2 Long-Term Pantropical Land Observation.

Christian N. Koyama, Manabu Watanabe, Masato Hayashi, Masanobu Shimada, Kazufumi Kobayashi, Takeo Tadono

Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, 2022

2021

Comparative Analysis of the Global Forest/Non-Forest Maps Derived from SAR and Optical Sensors. Case Studies from Brazilian Amazon and Cerrado Biomes.

Edson Eyji Sano, Paola Rizzoli, Christian N. Koyama, Manabu Watanabe, Marcos Adami, Yosio Edemir Shimabukuro, Gustavo Bayma, Daniel M. Freitas

Remote. Sens., 2021

Trial of Detection Accuracies Improvement for JJ-FAST Deforestation Detection Algorithm Using Deep Learning.

Manabu Watanabe, Christian N. Koyama, Masato Hayashi, Izumi Nagatani, Takeo Tadono, Masanobu Shimada

Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, 2021

Improving L-Band SAR Forest Monitoring by Big Data Deep Learning Based on ALOS-2 5 Years Pan-Tropical Observations.

Christian N. Koyama, Manabu Watanabe, Edson Eyji Sano, Masato Hayashi, Izumi Nagatani, Takeo Tadono, Masanobu Shimada

Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, 2021

2020

Trial of Deforestation Detection by Using 25M Resolution PALSAR-2/ScanSAR Data.

Manabu Watanabe, Christian N. Koyama, Masato Hayashi, Izumi Nagatani, Takeo Tadono, Masanobu Shimada

Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, 2020

Seasonal Change Analysis for ALOS-2 PALSAR-2 Deforestation Detection.

Izumi Nagatani, Masato Hayashi, Manabu Watanabe, Takeo Tadono, Tomohiro Watanabe, Christian N. Koyama, Masanobu Shimada

Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, 2020

Rainfall-Induced Changes in L-Band Backscatter Over Tropical Forests and Their Impact on Deforestation Monitoring.

Christian N. Koyama, Manabu Watanabe, Masato Hayashi, Izumi Nagatani, Takeo Tadono, Masanobu Shimada

Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, 2020

2019

Improvement of Deforestation Detection Algorithms Used In JJ-FAST.

Manabu Watanabe, Christian N. Koyama, Masato Hayashi, Izumi Nagatani, Takeo Tadono, Masanobu Shimada

Proceedings of the 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019

Pixel-Based Deforestation Detection Algorithm for ALOS-2/PALSAR-2.

Izumi Nagatani, Masato Hayashi, Manabu Watanabe, Takeo Tadono, Tomohiro Watanabe, Christian N. Koyama, Masanobu Shimada

Proceedings of the 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019

Mapping Spatial-Temporal Forest Heterogeneity in the Tropical Belt by ALOS-2/PALSAR-2 Big Data Analysis.

Christian N. Koyama, Manabu Watanabe, Masanobu Shimada

Proceedings of the 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019

Advanced Polarimetric Stereo-Sar for Tsunami Debris Estimation and Disaster Mitigation.

Christian N. Koyama, Shunichi Koshimura, Motoyuki Sato

Proceedings of the 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019

2018

Early-Stage Deforestation Detection in the Tropics With L-band SAR.

Manabu Watanabe, Christian N. Koyama, Masato Hayashi, Izumi Nagatani, Masanobu Shimada

IEEE J. Sel. Top. Appl. Earth Obs. Remote. Sens., 2018

Calibration Method for Multi Static Linear Array Radar with One Dimensional Array Antenna Arranged in Staggered Manner.

Yasunari Mori, Takayoshi Yumii, Yumi Asano, Kyouji Doi, Christian N. Koyama, Yasushi Iitsuka, Kazunori Takahashi, Motoyuki Sato

IEICE Trans. Electron., 2018

Semi-Automatic Deforestation Detection Algorithm with PALSAR-2/ScanSAR HH/HV Polarizations.

Manabu Watanabe, Christian N. Koyama, Masato Hayashi, Izumi Nagatani, Takeo Tadono, Masanobu Shimada

Proceedings of the 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018

Forest Early Warning System Using ALOS-2/PALSAR-2 Scansar Data (JJ-FAST).

Izumi Nagatani, Masato Hayashi, Manabu Watanabe, Takeo Tadano, Tomohiro Watanabe, Christian N. Koyama, Masanobu Shimada

Proceedings of the 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018

Monitoring of Soil Moisture Dynamics in the Semi-Arid Tropics by Means of ALOS-2/PALSAR-2 Dual-Polarization ScanSAR Data.

Christian N. Koyama, Manabu Watanabe, Masanobu Shimada

Proceedings of the 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018

2017

In-Situ Measurement of Soil Permittivity at Various Depths for the Calibration and Validation of Low-Frequency SAR Soil Moisture Models by Using GPR.

Christian N. Koyama, Hai Liu, Kazunori Takahashi, Masanobu Shimada, Manabu Watanabe, Tseedulam Khuut, Motoyuki Sato

Remote. Sens., 2017

Development of Multistatic Linear Array Radar at 10-20GHz.

Yasunari Mori, Takayoshi Yumii, Yumi Asano, Kyouji Doi, Christian N. Koyama, Yasushi Iitsuka, Kazunori Takahashi, Motoyuki Sato

IEICE Trans. Electron., 2017

Polarimetric characteristics of L-band SAR images of early-stage deforestation areas.

Manabu Watanabe, Christian N. Koyama, Masanobu Shimada

Proceedings of the 2017 IEEE International Geoscience and Remote Sensing Symposium, 2017

Development of early-stage deforestation detection algorithm (advanced) with PALSAR-2/ScanSAR for JICA-JAXA program (JJ-FAST).

Manabu Watanabe, Christian N. Koyama, Masato Hayashi, Yutaka Kaneko, Masanobu Shimada

Proceedings of the 2017 IEEE International Geoscience and Remote Sensing Symposium, 2017

The effect of precipitation and soil moisture variations on (partial) polarimetric L-band SAR backscatter in tropical forest regions.

Christian N. Koyama, Manabu Watanabe, Masato Hayashi, Masanobu Shimada

Proceedings of the 2017 IEEE International Geoscience and Remote Sensing Symposium, 2017

2016

Post-Earthquake Damage Inspection of Wood-Frame Buildings by a Polarimetric GB-SAR System.

Hai Liu, Christian N. Koyama, Jinfeng Zhu, Qing Huo Liu, Motoyuki Sato

Remote. Sens., 2016

2015

Development of a biomass corrected soil moisture retrieval model for dual-polarization ALOS-2 data based on ALOS/PALSAR and PI-SAR-L2 observations.

Christian N. Koyama, Karl Schneider, Motoyuki Sato

Proceedings of the 2015 IEEE International Geoscience and Remote Sensing Symposium, 2015

Full polarimetric UWB GB-SAR for damage assessment of wooden building structures.

Christian N. Koyama, Yasushi Iitsuka, Kazunori Takahashi, Motoyuki Sato

Proceedings of the 2015 IEEE International Geoscience and Remote Sensing Symposium, 2015

Urban damage mapping using scattering mechanism investigation technique for fully polarimetric SAR data.

Si-Wei Chen, Yongzhen Li, Xuesong Wang, Christian N. Koyama, Motoyuki Sato

Proceedings of the 2015 IEEE International Geoscience and Remote Sensing Symposium, 2015

2014

Investigation on near range SAR for inspecting inner structure of buildings.

Motoyuki Sato, Kazunori Takahashi, Hai Liu, Christian N. Koyama

Proceedings of the 2014 IEEE Geoscience and Remote Sensing Symposium, 2014

Estimation of soil moisture and debris pile volume from Pi-SAR2X and Pi-SAR-L2 square-flight data.

Christian N. Koyama, Motoyuki Sato

Proceedings of the 2014 IEEE Geoscience and Remote Sensing Symposium, 2014

2012

Vegetation effects on L-band soil moisture retrieval - Lessons learned from 5 years of ALOS PALSAR observations.

Christian N. Koyama, Karl Schneider

Proceedings of the 2012 IEEE International Geoscience and Remote Sensing Symposium, 2012

2011

Soil moisture retrieval under vegetation using dual polarized PALSAR data.

Christian N. Koyama, Karl Schneider

Proceedings of the 2011 IEEE International Geoscience and Remote Sensing Symposium, 2011