T. Tadono - Academia.edu (original) (raw)
Papers by T. Tadono
IEEE International Geoscience and Remote Sensing Symposium
Forest biomass is one of the key parameters that indicate temporal change of the global continent... more Forest biomass is one of the key parameters that indicate temporal change of the global continental carbon volumes, and its global estimation is required as described in the Kyoto protocol. NASDA's ALOS science project strongly intends its estimation either solely by SAR or in conjunction with the other optical sensors and the ground truth data. There have been (or are
2012 IEEE International Geoscience and Remote Sensing Symposium, 2012
ABSTRACT The recognition of concepts that we human beings are able to locate within satellite ima... more ABSTRACT The recognition of concepts that we human beings are able to locate within satellite imagery requires analysis based on the particular context using knowledge. In this paper, we present a supervised pixel-based classification approach toward utilization of the classification results in knowledgebased satellite data interpretation system. The proposed approach is based upon a generative model, which is able to output the classification results with their probabilities and subsequently utilize them in detailed analysis. The experiment of classification was performed to demonstrate characteristics of the approach.
IEEE Transactions on Geoscience and Remote Sensing, 2012
Simultaneous field data collections and Advanced Land Observing Satellite/Phased Array type L-ban... more Simultaneous field data collections and Advanced Land Observing Satellite/Phased Array type L-band Synthetic Aperture Radar (PALSAR) full polarimetry observations were performed in Ulaanbaatar (Mongolia) and Alaska (USA). Permafrost is present at the Alaska test sites. Backscattering copolarization (σ 0 co−pol) values derived from the PALSAR data were compared with those calculated using the integrated equation method (IEM) model, a popular theoretical model describing surface scattering. PALSAR data taken in Ulaanbaatar matched the IEM model results to within a few decibels, whereas data taken in Alaska were 5 to 7 dB lower than those calculated using the IEM model. On the other hand, the σ 0 cross−pol (σ 0 VH) components estimated from the Oh model were well matched to the PALSAR data in both Ulaanbaatar and Alaska. Moisture levels of the sphagnum moss layer in Alaska were estimated to be about 10% while moisture levels of the underlying organic and mineral layers were 25% to 79%; the moisture values of the organic and mineral layers were factored into the IEM and Oh models. When surface moisture levels of 10% were assumed for Alaska ground conditions, the σ 0 co−pol values calculated using the IEM model and those derived from the PALSAR data were well matched. From these observations, we conclude that the sphagnum moss layer, which is a seasonally unfrozen layer that occurs above permafrost, plays an important role in radar backscattering processes in permafrost regions and is a main contributor to the σ 0 co−pol backscattering component; the underlying organic and mineral layers contribute mainly to the σ 0 cross−pol backscattering component. A two-layer model was applied to the data from a test site in Alaska; the model described the co-and cross-polarization backscatter (σ 0) derived from PALSAR data with off-nadir angles of 21.5 • and 34.3 • .
The objectives of this study are to validate generated Digital Surface Models (DSMs) by PRISM onb... more The objectives of this study are to validate generated Digital Surface Models (DSMs) by PRISM onboard the Advanced Land Observing Satellite (ALOS, nicknamed “Daichi”) in snow and glacier regions to contribute to the evaluation of potential Glacial Lake Outburst Floods (GLOFs) and their mitigation in the Bhutan Himalaya. Glacial lake inventory will also be generated to investigate the expansion process of glacial lakes using historical satellite imageries, including those by ALOS, as current conditions. Failures of glacial lake dams terminated by natural moraines can cause outburst floods and represent a serious hazard to downstream regions. The development and expansion of glacial lakes is sometimes said to be due to recent global warming, while other researchers say no correlation between them exists. The fact is, people living in such regions are exposed to the risk of GLOFs. To mitigate the damage of GLOFs, investigation into the melting process of glaciers and the development an...
Geosciences, 2020
In Kyrgyzstan, outburst flood disasters from glacial lakes are increasing. An example is the sudd... more In Kyrgyzstan, outburst flood disasters from glacial lakes are increasing. An example is the sudden drainage on 8 August 2019 of the Toguz-Bulak glacial lake in the Tosor river basin of the northern Tien Shan region. In this study, we used remote sensing and field surveys to examine the reasons for the outburst. We found that the lake area changed from 0.021 km² to 0.002 km2 due to the outburst, in which most of the initial 130,000 m3 of water discharged within four hours. In examining the longer-term behavior of this lake, we found that from 2010 through 2019, it appears in June and disappears in September every year. Its maximum area occurs in late July and early August. With the expansion of the lake basin between 2010 and 2019, the lake also increased greatly in size, particularly so in the three years before the outburst, linked to high summer temperatures and the resulting higher inflow of glacier meltwater, finally leading to the sudden drainage in 2019. Before this outburst,...
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2021
In 2016, the first processing of the semi-global digital surface models (DSMs) utilizing all the ... more In 2016, the first processing of the semi-global digital surface models (DSMs) utilizing all the archives of stereo imageries derived from the Panchromatic Remote sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS) was successfully completed. The dataset was freely released to the public in 30 m grid spacing as the 'ALOS World 3D-30m (AW3D30)', which was generated from its original version processed in 5 m or 2.5 m grid spacing. The dataset has been updated since then to improve the absolute/relative height accuracies with additional calibrations. However, the most significant update that should be applied for improving the data usability is the filling of void areas, which correspond to approx. 10% of semiglobal coverage, mostly due to cloud covers. In 2020, we completed the filling process by using other open-access digital elevation models (DEMs) such as Shuttle Radar Topography Mission (SRTM) DEM, Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM (ASTER GDEM), ArcticDEM, etc., except for Antarctica. In this paper, we report on the filling process of the remaining voids in Antarctica by using other open-access DEMs such as Reference Elevation Model of Antarctica (REMA) DSM, TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X, TDX) 90m DEM, and ASTER GDEM to complete the void-free semi-global AW3D30 datasets.
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020
The "Advanced Land Observing Satellite-3" (ALOS-3, nicknamed "DAICHI-3") is the next high-resolut... more The "Advanced Land Observing Satellite-3" (ALOS-3, nicknamed "DAICHI-3") is the next high-resolution optical mission as a successor of the optical mission by the Advanced Land Observing Satellite (ALOS, "DAICHI") in Japan Aerospace Exploration Agency (JAXA), and will be launched in Japanese Fiscal Year 2020. ALOS-3 is now under developing the flight model. The major missions of ALOS-3 are (1) to contribute safe and secure social including provision for natural disasters, and (2) to create and update geospatial information in land and coastal areas. To achieve the missions, the "WIde-Swath and High-resolution optical imager" (WISH, as a tentative name) is mounted on ALOS-3, which consists of the high-resolution panchromatic-and multispectral-bands. This paper introduces the overview of ALOS-3's mission and the calibration and validation plan at JAXA. The standard product is the system corrected data using the sensor models, which will be provided from the sensor development team. Therefore, the sensor calibration is directly affected to the accuracies of the standard product. In addition, the sensor model based the Rational Polynomial Coefficient will be contained with level 1B2 standard product that can be used to process an ortho rectification and threedimensional measurement from ALOS-3 images. As the target accuracy of WISH's standard products, the geometric accuracies are less than 5 m in horizontal without ground control point (GCP), and 1.25 m in horizontal and 2.5 m in vertical with GCPs (1 sigma), and the radiometric accuracy is +/-10 % as absolutely and +/-5 % as relatively for multispectral band.
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020
In 2016 we first completed the global data processing of digital surface models (DSMs) by using t... more In 2016 we first completed the global data processing of digital surface models (DSMs) by using the whole archives of stereo imageries derived from the Panchromatic Remote sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS). The dataset was freely released to the public in 30 m grid spacing as the 'ALOS World 3D-30m (AW3D30)', which was generated from its original version processed in 5 m or 2.5 m grid spacing. The dataset has been updated since then to improve the absolute/relative height accuracies with additional calibrations. However the most significant update that should be applied for improving the data usability is the filling of void areas, which correspond to approx. 10% of global coverage, mostly due to cloud covers. In this paper we introduce the updates of AW3D30 filling the voids with other open-access DSMs such as Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM), Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM (ASTER GDEM), ArcticDEM, etc., through inter-comparisons among these datasets.
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2019
The Advanced Land Observing Satellite-2 (ALOS-2) was launched on May 24, 2014, and it is operatin... more The Advanced Land Observing Satellite-2 (ALOS-2) was launched on May 24, 2014, and it is operating very well in space more than 4.5 years. The designed mission life is five years as nominal operational phase and the target is over seven years since launch the satellite. The mission objectives of ALOS-2 are 1) disaster monitoring, 2) national land and infrastructure information, 3) cultivated area monitoring, and 4) global forest monitoring. To achieve the objectives, ALOS-2 carries on the Phased Array type Lband Synthetic Aperture Radar-2 (PALSAR-2), which is an active microwave radar using the 1.2 GHz frequency band and observes in day and night times even in bad weather conditions as successor PALSAR instrument onboard ALOS satellite operated from 2006 to 2011. PALSAR-2 instrument has several enhanced features from PALSAR e.g. finer spatial resolution, spotlight observing mode, dual-polarisation ScanSAR. This paper summarises an introduction of typical data analysis results for monitoring natural disasters by ALOS-2 during the operational phase. As the response natural disasters, more than 400 times of the emergency observations have been conducted to identify damages caused by volcanic activities, earthquakes, flooding etc. happened in Japan and the World.
ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences, 2019
Accuracy assessment of forest type maps is essential to evaluate the classification of forest eco... more Accuracy assessment of forest type maps is essential to evaluate the classification of forest ecosystems quantitatively. However, map users do not understand in which regions those forest types are well classified from conventional static accuracy measures. Hence, the objective of this study is to unveil spatial heterogeneities of accuracies of forest type classification in a map. Four forest types (deciduous broadleaf forest (DBF), deciduous needleleaf forest (DNF), evergreen broadleaf forest (EBF), and evergreen needleleaf forest (ENF)) found in the JAXA's land use / cover map of Japan were assessed by a volunteered Site-based dataset for Assessment of Changing LAnd cover by JAXA (SACLAJ). A geographically weighted (GW) correspondence matrix was applied to them to calculate the degree of overall agreements of forest type classes (forest overall accuracy), and the degree of accuracy for each forest class (forest user's and producer's accuracies) in a spatially varying way. This study compared spatial surfaces of these measures with static ones of them. The results show that the forest overall accuracy of the forest map tends to be relatively more accurate in the central Japan, while less in the Kansai and Chubu regions and the northern edge of Hokkaido. Static forest user's accuracy measures for DBF, DNF, and ENF are better than forest producer's accuracy ones, while the GW approach tells us such characteristics vary spatially and some areas have opposite trends. This kind of spatial accuracy assessment provides a more informative description of the accuracy than the simple use of conventional accuracy measures.
Sustainability, 2018
The horizontal two-dimensional (2D) urban land use approach is not sufficient to trace rapid chan... more The horizontal two-dimensional (2D) urban land use approach is not sufficient to trace rapid changes in urban environment. Hence, a three-dimensional (3D) approach that is different from the traditional geographical method is necessary to understand the mechanism of compound urban diversity. Using remote sensing data captured in 2010/2011 and geospatial tools and techniques, we quantified the urban volume (UV, consisting of urban built volume (UBV) and urban green volume (UGV)) and retrieved and mapped the land surface temperature (LST) of two cities in Japan (Tsukuba, a planned city, and Tsuchiura, a traditional city). We compared these two cities in terms of (1) UBV and UGV and their relationships with mean LST; and (2) the relationship of the UGV-UBV ratio with mean LST. Tsukuba had a total UBV of 74 million m 3 , while Tsuchiura had a total of 89 million m 3. In terms of UGV, Tsukuba had a total of 52 million m 3 , while Tsuchiura had a total of 29 million m 3. In both cities, UBV had a positive relationship with mean LST (Tsukuba: R 2 = 0.31, p < 0.001; Tsuchiura: R 2 = 0.42, p < 0.001), and UGV had a negative relationship with mean LST (Tsukuba: R 2 = 0.53, p < 0.001; Tsuchiura: R 2 = 0.19, p < 0.001). Tsukuba also had a higher UGV-UBV ratio of 54.9% in comparison with Tsuchiura, with 28.7%. Overall, the results indicate that mean LST was more intense in the traditional city (Tsuchiura). This could have been due to the difference in urban spatial structure. As a planned city, Tsukuba is still a relatively young city that has more dispersed green spaces and a well-spread (so far) built-up area.
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2016
Topographical information is fundamental to many geo-spatial related information and applications... more Topographical information is fundamental to many geo-spatial related information and applications on Earth. Remote sensing satellites have the advantage in such fields because they are capable of global observation and repeatedly. Several satellite-based digital elevation datasets were provided to examine global terrains with medium resolutions e.g. the Shuttle Radar Topography Mission (SRTM), the global digital elevation model by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER GDEM). A new global digital surface model (DSM) dataset using the archived data of the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS, nicknamed “Daichi”) has been completed on March 2016 by Japan Aerospace Exploration Agency (JAXA) collaborating with NTT DATA Corp. and Remote Sensing Technology Center, Japan. This project is called “ALOS World 3D” (AW3D), and its dataset consists of the global DSM dataset with 0....
The Cryosphere, 2016
Digital glacier inventories are invaluable data sets for revealing the characteristics of glacier... more Digital glacier inventories are invaluable data sets for revealing the characteristics of glacier distribution and for upscaling measurements from selected locations to entire mountain ranges. Here, we present a new inventory of Advanced Land Observing Satellite (ALOS) imagery and compare it with existing inventories for the Bhutan Himalaya. The new inventory contains 1583 glaciers (1487 ± 235 km 2), thereof 219 debris-covered glaciers (951 ± 193 km 2) and 1364 debris-free glaciers (536 ± 42 km 2). Moreover, we propose an index for quantifying consistency between two glacier outlines. Comparison of the overlap ratio demonstrates that the ALOS-derived glacier inventory contains delineation uncertainties of 10-20 % which depend on glacier size, that the shapes and geographical locations of glacier outlines derived from the fourth version of the Randolph Glacier Inventory have been improved in the fifth version, and that the latter is consistent with other inventories. In terms of whole glacier distribution, each data set is dominated by glaciers of 1.0-5.0 km 2 area (31-34 % of the total area), situated at approximately 5400 m elevation (nearly 10 % in 100 m bin) with either north or south aspects (22 and 15 %). However, individual glacier outlines and their area exhibit clear differences among inventories. Furthermore, consistent separation of glaciers with inconspicuous termini remains difficult, which, in some cases, results in different values for glacier number. High-resolution imagery from Google Earth can be used to improve the interpretation of glacier outlines, particularly for debris-covered areas and steep adjacent slopes.
With the launch of ALOS in 2006, JAXA took the initiative to implement the first global-scale sys... more With the launch of ALOS in 2006, JAXA took the initiative to implement the first global-scale systematic acquisition strategy for satellite sensors at fine (2.5m-20m) spatial resolution. Comprising all three sensors on ALOS (PALSAR, PRISM, AVNIR-2), the plan is designed to serve all ALOS user categories and aims at producing spatially and temporally consistent coverages over the planet on a repetitive basis, to accommodate systematic global-scale, fine-resolution, monitoring of the environment. Unlike the common background missions defined for most fineresolution Earth Observation satellites, the BOS has been implemented as a top-level foreground mission with a priority second only to that of special observation requests and emergency observations and sensor cal/val. Presently 4 years in operation, the strategy has produced a comprehensive and homogeneous global archive in which consistent time-series of data are available for any arbitrary point or region on Earth. Clouds and haze inevitably constitute limitations for the oprtical sensors, while for the PALSAR instrument, two cloud-free and near-gap free (~95%) global coverages are achieved annually. Previously, such uniform data archives existed only for coarse and midresolution sensors such as AVHRR, MERIS and MODIS.
IGARSS 2001. Scanning the Present and Resolving the Future. Proceedings. IEEE 2001 International Geoscience and Remote Sensing Symposium (Cat. No.01CH37217)
Cross-calibration experiment of airborne L-band SAR systems, the JPL's AIRSAR and the NAS... more Cross-calibration experiment of airborne L-band SAR systems, the JPL's AIRSAR and the NASDA/CRL's PI-SAR, was conducted on the Tottori sand dune. This experiment forms a part of PacificRim-2 campaign from July to October in 2000. Both AIRSAR and PI-SAR acquired the data over the test site within two hours on October 4, 2000. The track altitudes of airplanes were about
IGARSS 2001. Scanning the Present and Resolving the Future. Proceedings. IEEE 2001 International Geoscience and Remote Sensing Symposium (Cat. No.01CH37217), 2001
Interferometric phase difference among the SAR and trees, composed of trunks, branches, and canop... more Interferometric phase difference among the SAR and trees, composed of trunks, branches, and canopies, provides an information related to trees heights and structures at a given polarization. Vertical polarization (like) is sensitive on the vertical structure and the horizontal pot. (like) for the horizontal one. Cross pol. is sensitive to the inclined branches (inclined cylinder depolarizes the incoming signal). Thus,
IEEE International Geoscience and Remote Sensing Symposium
Forest biomass is one of the key parameters that indicate temporal change of the global continent... more Forest biomass is one of the key parameters that indicate temporal change of the global continental carbon volumes, and its global estimation is required as described in the Kyoto protocol. NASDA&#39;s ALOS science project strongly intends its estimation either solely by SAR or in conjunction with the other optical sensors and the ground truth data. There have been (or are
2012 IEEE International Geoscience and Remote Sensing Symposium, 2012
ABSTRACT The recognition of concepts that we human beings are able to locate within satellite ima... more ABSTRACT The recognition of concepts that we human beings are able to locate within satellite imagery requires analysis based on the particular context using knowledge. In this paper, we present a supervised pixel-based classification approach toward utilization of the classification results in knowledgebased satellite data interpretation system. The proposed approach is based upon a generative model, which is able to output the classification results with their probabilities and subsequently utilize them in detailed analysis. The experiment of classification was performed to demonstrate characteristics of the approach.
IEEE Transactions on Geoscience and Remote Sensing, 2012
Simultaneous field data collections and Advanced Land Observing Satellite/Phased Array type L-ban... more Simultaneous field data collections and Advanced Land Observing Satellite/Phased Array type L-band Synthetic Aperture Radar (PALSAR) full polarimetry observations were performed in Ulaanbaatar (Mongolia) and Alaska (USA). Permafrost is present at the Alaska test sites. Backscattering copolarization (σ 0 co−pol) values derived from the PALSAR data were compared with those calculated using the integrated equation method (IEM) model, a popular theoretical model describing surface scattering. PALSAR data taken in Ulaanbaatar matched the IEM model results to within a few decibels, whereas data taken in Alaska were 5 to 7 dB lower than those calculated using the IEM model. On the other hand, the σ 0 cross−pol (σ 0 VH) components estimated from the Oh model were well matched to the PALSAR data in both Ulaanbaatar and Alaska. Moisture levels of the sphagnum moss layer in Alaska were estimated to be about 10% while moisture levels of the underlying organic and mineral layers were 25% to 79%; the moisture values of the organic and mineral layers were factored into the IEM and Oh models. When surface moisture levels of 10% were assumed for Alaska ground conditions, the σ 0 co−pol values calculated using the IEM model and those derived from the PALSAR data were well matched. From these observations, we conclude that the sphagnum moss layer, which is a seasonally unfrozen layer that occurs above permafrost, plays an important role in radar backscattering processes in permafrost regions and is a main contributor to the σ 0 co−pol backscattering component; the underlying organic and mineral layers contribute mainly to the σ 0 cross−pol backscattering component. A two-layer model was applied to the data from a test site in Alaska; the model described the co-and cross-polarization backscatter (σ 0) derived from PALSAR data with off-nadir angles of 21.5 • and 34.3 • .
The objectives of this study are to validate generated Digital Surface Models (DSMs) by PRISM onb... more The objectives of this study are to validate generated Digital Surface Models (DSMs) by PRISM onboard the Advanced Land Observing Satellite (ALOS, nicknamed “Daichi”) in snow and glacier regions to contribute to the evaluation of potential Glacial Lake Outburst Floods (GLOFs) and their mitigation in the Bhutan Himalaya. Glacial lake inventory will also be generated to investigate the expansion process of glacial lakes using historical satellite imageries, including those by ALOS, as current conditions. Failures of glacial lake dams terminated by natural moraines can cause outburst floods and represent a serious hazard to downstream regions. The development and expansion of glacial lakes is sometimes said to be due to recent global warming, while other researchers say no correlation between them exists. The fact is, people living in such regions are exposed to the risk of GLOFs. To mitigate the damage of GLOFs, investigation into the melting process of glaciers and the development an...
Geosciences, 2020
In Kyrgyzstan, outburst flood disasters from glacial lakes are increasing. An example is the sudd... more In Kyrgyzstan, outburst flood disasters from glacial lakes are increasing. An example is the sudden drainage on 8 August 2019 of the Toguz-Bulak glacial lake in the Tosor river basin of the northern Tien Shan region. In this study, we used remote sensing and field surveys to examine the reasons for the outburst. We found that the lake area changed from 0.021 km² to 0.002 km2 due to the outburst, in which most of the initial 130,000 m3 of water discharged within four hours. In examining the longer-term behavior of this lake, we found that from 2010 through 2019, it appears in June and disappears in September every year. Its maximum area occurs in late July and early August. With the expansion of the lake basin between 2010 and 2019, the lake also increased greatly in size, particularly so in the three years before the outburst, linked to high summer temperatures and the resulting higher inflow of glacier meltwater, finally leading to the sudden drainage in 2019. Before this outburst,...
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2021
In 2016, the first processing of the semi-global digital surface models (DSMs) utilizing all the ... more In 2016, the first processing of the semi-global digital surface models (DSMs) utilizing all the archives of stereo imageries derived from the Panchromatic Remote sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS) was successfully completed. The dataset was freely released to the public in 30 m grid spacing as the 'ALOS World 3D-30m (AW3D30)', which was generated from its original version processed in 5 m or 2.5 m grid spacing. The dataset has been updated since then to improve the absolute/relative height accuracies with additional calibrations. However, the most significant update that should be applied for improving the data usability is the filling of void areas, which correspond to approx. 10% of semiglobal coverage, mostly due to cloud covers. In 2020, we completed the filling process by using other open-access digital elevation models (DEMs) such as Shuttle Radar Topography Mission (SRTM) DEM, Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM (ASTER GDEM), ArcticDEM, etc., except for Antarctica. In this paper, we report on the filling process of the remaining voids in Antarctica by using other open-access DEMs such as Reference Elevation Model of Antarctica (REMA) DSM, TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X, TDX) 90m DEM, and ASTER GDEM to complete the void-free semi-global AW3D30 datasets.
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020
The "Advanced Land Observing Satellite-3" (ALOS-3, nicknamed "DAICHI-3") is the next high-resolut... more The "Advanced Land Observing Satellite-3" (ALOS-3, nicknamed "DAICHI-3") is the next high-resolution optical mission as a successor of the optical mission by the Advanced Land Observing Satellite (ALOS, "DAICHI") in Japan Aerospace Exploration Agency (JAXA), and will be launched in Japanese Fiscal Year 2020. ALOS-3 is now under developing the flight model. The major missions of ALOS-3 are (1) to contribute safe and secure social including provision for natural disasters, and (2) to create and update geospatial information in land and coastal areas. To achieve the missions, the "WIde-Swath and High-resolution optical imager" (WISH, as a tentative name) is mounted on ALOS-3, which consists of the high-resolution panchromatic-and multispectral-bands. This paper introduces the overview of ALOS-3's mission and the calibration and validation plan at JAXA. The standard product is the system corrected data using the sensor models, which will be provided from the sensor development team. Therefore, the sensor calibration is directly affected to the accuracies of the standard product. In addition, the sensor model based the Rational Polynomial Coefficient will be contained with level 1B2 standard product that can be used to process an ortho rectification and threedimensional measurement from ALOS-3 images. As the target accuracy of WISH's standard products, the geometric accuracies are less than 5 m in horizontal without ground control point (GCP), and 1.25 m in horizontal and 2.5 m in vertical with GCPs (1 sigma), and the radiometric accuracy is +/-10 % as absolutely and +/-5 % as relatively for multispectral band.
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020
In 2016 we first completed the global data processing of digital surface models (DSMs) by using t... more In 2016 we first completed the global data processing of digital surface models (DSMs) by using the whole archives of stereo imageries derived from the Panchromatic Remote sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS). The dataset was freely released to the public in 30 m grid spacing as the 'ALOS World 3D-30m (AW3D30)', which was generated from its original version processed in 5 m or 2.5 m grid spacing. The dataset has been updated since then to improve the absolute/relative height accuracies with additional calibrations. However the most significant update that should be applied for improving the data usability is the filling of void areas, which correspond to approx. 10% of global coverage, mostly due to cloud covers. In this paper we introduce the updates of AW3D30 filling the voids with other open-access DSMs such as Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM), Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM (ASTER GDEM), ArcticDEM, etc., through inter-comparisons among these datasets.
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2019
The Advanced Land Observing Satellite-2 (ALOS-2) was launched on May 24, 2014, and it is operatin... more The Advanced Land Observing Satellite-2 (ALOS-2) was launched on May 24, 2014, and it is operating very well in space more than 4.5 years. The designed mission life is five years as nominal operational phase and the target is over seven years since launch the satellite. The mission objectives of ALOS-2 are 1) disaster monitoring, 2) national land and infrastructure information, 3) cultivated area monitoring, and 4) global forest monitoring. To achieve the objectives, ALOS-2 carries on the Phased Array type Lband Synthetic Aperture Radar-2 (PALSAR-2), which is an active microwave radar using the 1.2 GHz frequency band and observes in day and night times even in bad weather conditions as successor PALSAR instrument onboard ALOS satellite operated from 2006 to 2011. PALSAR-2 instrument has several enhanced features from PALSAR e.g. finer spatial resolution, spotlight observing mode, dual-polarisation ScanSAR. This paper summarises an introduction of typical data analysis results for monitoring natural disasters by ALOS-2 during the operational phase. As the response natural disasters, more than 400 times of the emergency observations have been conducted to identify damages caused by volcanic activities, earthquakes, flooding etc. happened in Japan and the World.
ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences, 2019
Accuracy assessment of forest type maps is essential to evaluate the classification of forest eco... more Accuracy assessment of forest type maps is essential to evaluate the classification of forest ecosystems quantitatively. However, map users do not understand in which regions those forest types are well classified from conventional static accuracy measures. Hence, the objective of this study is to unveil spatial heterogeneities of accuracies of forest type classification in a map. Four forest types (deciduous broadleaf forest (DBF), deciduous needleleaf forest (DNF), evergreen broadleaf forest (EBF), and evergreen needleleaf forest (ENF)) found in the JAXA's land use / cover map of Japan were assessed by a volunteered Site-based dataset for Assessment of Changing LAnd cover by JAXA (SACLAJ). A geographically weighted (GW) correspondence matrix was applied to them to calculate the degree of overall agreements of forest type classes (forest overall accuracy), and the degree of accuracy for each forest class (forest user's and producer's accuracies) in a spatially varying way. This study compared spatial surfaces of these measures with static ones of them. The results show that the forest overall accuracy of the forest map tends to be relatively more accurate in the central Japan, while less in the Kansai and Chubu regions and the northern edge of Hokkaido. Static forest user's accuracy measures for DBF, DNF, and ENF are better than forest producer's accuracy ones, while the GW approach tells us such characteristics vary spatially and some areas have opposite trends. This kind of spatial accuracy assessment provides a more informative description of the accuracy than the simple use of conventional accuracy measures.
Sustainability, 2018
The horizontal two-dimensional (2D) urban land use approach is not sufficient to trace rapid chan... more The horizontal two-dimensional (2D) urban land use approach is not sufficient to trace rapid changes in urban environment. Hence, a three-dimensional (3D) approach that is different from the traditional geographical method is necessary to understand the mechanism of compound urban diversity. Using remote sensing data captured in 2010/2011 and geospatial tools and techniques, we quantified the urban volume (UV, consisting of urban built volume (UBV) and urban green volume (UGV)) and retrieved and mapped the land surface temperature (LST) of two cities in Japan (Tsukuba, a planned city, and Tsuchiura, a traditional city). We compared these two cities in terms of (1) UBV and UGV and their relationships with mean LST; and (2) the relationship of the UGV-UBV ratio with mean LST. Tsukuba had a total UBV of 74 million m 3 , while Tsuchiura had a total of 89 million m 3. In terms of UGV, Tsukuba had a total of 52 million m 3 , while Tsuchiura had a total of 29 million m 3. In both cities, UBV had a positive relationship with mean LST (Tsukuba: R 2 = 0.31, p < 0.001; Tsuchiura: R 2 = 0.42, p < 0.001), and UGV had a negative relationship with mean LST (Tsukuba: R 2 = 0.53, p < 0.001; Tsuchiura: R 2 = 0.19, p < 0.001). Tsukuba also had a higher UGV-UBV ratio of 54.9% in comparison with Tsuchiura, with 28.7%. Overall, the results indicate that mean LST was more intense in the traditional city (Tsuchiura). This could have been due to the difference in urban spatial structure. As a planned city, Tsukuba is still a relatively young city that has more dispersed green spaces and a well-spread (so far) built-up area.
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2016
Topographical information is fundamental to many geo-spatial related information and applications... more Topographical information is fundamental to many geo-spatial related information and applications on Earth. Remote sensing satellites have the advantage in such fields because they are capable of global observation and repeatedly. Several satellite-based digital elevation datasets were provided to examine global terrains with medium resolutions e.g. the Shuttle Radar Topography Mission (SRTM), the global digital elevation model by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER GDEM). A new global digital surface model (DSM) dataset using the archived data of the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS, nicknamed “Daichi”) has been completed on March 2016 by Japan Aerospace Exploration Agency (JAXA) collaborating with NTT DATA Corp. and Remote Sensing Technology Center, Japan. This project is called “ALOS World 3D” (AW3D), and its dataset consists of the global DSM dataset with 0....
The Cryosphere, 2016
Digital glacier inventories are invaluable data sets for revealing the characteristics of glacier... more Digital glacier inventories are invaluable data sets for revealing the characteristics of glacier distribution and for upscaling measurements from selected locations to entire mountain ranges. Here, we present a new inventory of Advanced Land Observing Satellite (ALOS) imagery and compare it with existing inventories for the Bhutan Himalaya. The new inventory contains 1583 glaciers (1487 ± 235 km 2), thereof 219 debris-covered glaciers (951 ± 193 km 2) and 1364 debris-free glaciers (536 ± 42 km 2). Moreover, we propose an index for quantifying consistency between two glacier outlines. Comparison of the overlap ratio demonstrates that the ALOS-derived glacier inventory contains delineation uncertainties of 10-20 % which depend on glacier size, that the shapes and geographical locations of glacier outlines derived from the fourth version of the Randolph Glacier Inventory have been improved in the fifth version, and that the latter is consistent with other inventories. In terms of whole glacier distribution, each data set is dominated by glaciers of 1.0-5.0 km 2 area (31-34 % of the total area), situated at approximately 5400 m elevation (nearly 10 % in 100 m bin) with either north or south aspects (22 and 15 %). However, individual glacier outlines and their area exhibit clear differences among inventories. Furthermore, consistent separation of glaciers with inconspicuous termini remains difficult, which, in some cases, results in different values for glacier number. High-resolution imagery from Google Earth can be used to improve the interpretation of glacier outlines, particularly for debris-covered areas and steep adjacent slopes.
With the launch of ALOS in 2006, JAXA took the initiative to implement the first global-scale sys... more With the launch of ALOS in 2006, JAXA took the initiative to implement the first global-scale systematic acquisition strategy for satellite sensors at fine (2.5m-20m) spatial resolution. Comprising all three sensors on ALOS (PALSAR, PRISM, AVNIR-2), the plan is designed to serve all ALOS user categories and aims at producing spatially and temporally consistent coverages over the planet on a repetitive basis, to accommodate systematic global-scale, fine-resolution, monitoring of the environment. Unlike the common background missions defined for most fineresolution Earth Observation satellites, the BOS has been implemented as a top-level foreground mission with a priority second only to that of special observation requests and emergency observations and sensor cal/val. Presently 4 years in operation, the strategy has produced a comprehensive and homogeneous global archive in which consistent time-series of data are available for any arbitrary point or region on Earth. Clouds and haze inevitably constitute limitations for the oprtical sensors, while for the PALSAR instrument, two cloud-free and near-gap free (~95%) global coverages are achieved annually. Previously, such uniform data archives existed only for coarse and midresolution sensors such as AVHRR, MERIS and MODIS.
IGARSS 2001. Scanning the Present and Resolving the Future. Proceedings. IEEE 2001 International Geoscience and Remote Sensing Symposium (Cat. No.01CH37217)
Cross-calibration experiment of airborne L-band SAR systems, the JPL's AIRSAR and the NAS... more Cross-calibration experiment of airborne L-band SAR systems, the JPL's AIRSAR and the NASDA/CRL's PI-SAR, was conducted on the Tottori sand dune. This experiment forms a part of PacificRim-2 campaign from July to October in 2000. Both AIRSAR and PI-SAR acquired the data over the test site within two hours on October 4, 2000. The track altitudes of airplanes were about
IGARSS 2001. Scanning the Present and Resolving the Future. Proceedings. IEEE 2001 International Geoscience and Remote Sensing Symposium (Cat. No.01CH37217), 2001
Interferometric phase difference among the SAR and trees, composed of trunks, branches, and canop... more Interferometric phase difference among the SAR and trees, composed of trunks, branches, and canopies, provides an information related to trees heights and structures at a given polarization. Vertical polarization (like) is sensitive on the vertical structure and the horizontal pot. (like) for the horizontal one. Cross pol. is sensitive to the inclined branches (inclined cylinder depolarizes the incoming signal). Thus,