Dual-frequency Precipitation Radar (DPR) on the core satellite of Global Precipitation Measuremen... more Dual-frequency Precipitation Radar (DPR) on the core satellite of Global Precipitation Measurement (GPM) mission has changed its scan pattern in May 2018. As the high-sensitivity measurement of KaPR has been moved to the outer swath from the inner swath, all pixels are measured by both KuPR and KaPR after the scan pattern change. Experimental product (DPR Version 06X; V6X in short) for the new scan pattern applies dual-frequency algorithm for the outer swath. In this study, precipitation rates and other outputs of V6X are analyzed. Dual-frequency algorithm of V6X shows strong incident angle dependence of precipitation rates in the outer swath.
The GPM core satellite is scheduled to be launched on February 28, 2014. It carries the Dual-Freq... more The GPM core satellite is scheduled to be launched on February 28, 2014. It carries the Dual-Frequency Precipitation Radar (DPR) developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT), which consists of two radars: Ku-band precipitation radar (KuPR, 13.6 GHz) and Ka-band radar (KaPR, 35.5 GHz). NICT is planning the GPM/DPR onboard calibration experiment at NICT Koganei. The beam matching of two radars will be evaluated. NICT is also planning the post-launch ground validation (product validation) experiment at two locations, NICT Kobe (NICT Advanced ICT Research Institute) and NICT Okinawa (Okinawa Electromagnetic Technology Center). NICT is developing two X-band phased array radars (PANDA: Phased Array radar Network DAta system) and will install at NICT Kobe and Okinawa. PANDA can scan three-dimensionally in thirty seconds. We can compare the radar directly and simultaneously. At NICT Okinawa, the C-band polarimetric Doppler radar (COBRA) is also installed. The differential reflectivity (ZDR) can be used to validate the rain drop size distribution parameter (D 0). The cross-correlation coefficient (ρHV) can be used to validate the melting layer flag. Using the ground-based rain drop size measurements, the two-dimensional Video disdtrometer (2DVD), Joss-type disdrometer, and Laser Optical disdrometr (Parsivel), and so on, the characteristics of DSD itself are analyzed and the k-Z relationship is estimated for evaluation and improvement of the GPM/DPR algorithm.
(NICT), we promote advanced research and development of remote sensing technology, to reduce the ... more (NICT), we promote advanced research and development of remote sensing technology, to reduce the damage of severe weather disasters caused by localized heavy rainfalls or tornadoes. An industry-academia-government team consisting of Toshiba, Osaka University, and NICT developed one-dimensional phased array weather radar (PAWR) that it is possible to seamless 3D observation in 10 ? 30 seconds. In May 2012, we installed PAWR at Osaka University Suita Campus, and started test observation. From the observation, a first echo appeared in an isolated cumulonimbus cloud was falling to the ground for about 10 minutes. In order to predict the generation point of the cumulonimbus cloud, we need other data which includes wind fields before cloud generation, distributions of water vapor and aerosol, and so on. For that reason, we develop a sensor fusion system with PAWR, Doppler lidar, and others. We install the systems to both NICT Advanced ICT Research Institute (Iwaoka, Nishi-ku, Kobe, Hyogo) and NICT Okinawa Electromagnetic Technology Center (Onna, Kunigami, Okinawa), and install the network data system to NICT headquarters (Koganei, Tokyo). The sensor fusion system consists of the PAWR antenna in a radome installed on the roof of a 20 m tower, Doppler lidar (Leosphere 400s) on the deck at the height of 15 m of the tower, microwave radiometer to measure water vapor, and sky-radiometer to measure aerosol. Also, temperature, humidity, wind speed components (u, v, w), pressure, rainfall amount, radiation budget, and cloud images (4 directions and whole sky) are measured. All sensors are connected by network for remote operation and automatic data acquisition. The observation data are transferred in real-time through the fast network lines (JGN-X) from Kobe and Okinawa to Koganei for data processing to make a composite map, and so on. The processing data are displayed on a big 4K display TV, and are published using a web server. We will start test observation after the system completion in March, 2014. At NICT, we also promote research and development of network data system using advanced ICT for big-data processing, transfer, visualization. We give this system a nickname of PANDA: Phased Array weather radar and Doppler lidar Network fusion DAta system, and will publish the data from http://panda.nict.go.jp/.
Precipitation observation by the Tropical Rainfall Measuring Mission' s (TRMM' s) Precipitation R... more Precipitation observation by the Tropical Rainfall Measuring Mission' s (TRMM' s) Precipitation Radar (PR) has lasted for almost 17 years. On February 28, 2014, the core satellite of the Global Precipitation Measurement (GPM) mission was launched, and the GPM Dual-frequency Precipitation Radar (DPR) started providing precipitation data succeeding the TRMM PR observation. PR and DPR not only estimate precipitation accurately both over land and the oceans but also provide information to derive precipitation characteristics (e.g., rain top height and rain vertical profile). Homogeneity of long-term PR/DPR data will be essential to study the water cycle change related to the decadal climate variability. In this study, we aim to develop a precipitation climate data from 17-year PR data. The PR data have discontinuities in quality due to the boost of the TRMM satellite altitude in August 2001 and the PR hardware (H/W) change in June 2009. In this paper, PR data are adjusted to mitigate the discontinuity of the PR H/W change. The observation of PR temporary stopped on May 29, 2009. The PR H/W changed from Aside to B-side and the B-side observation has started since June 19, 2009, which causes the drop of noise power. The difference in noise power between 2008 and 2010 is obtained as a decrease of 0.54 dBm. This change affects a minimum detection of weak rain by PR. In the current study, the B-side PR data are adjusted to simulate the data with the characteristics of Aside PR. The simulated data are created with the additional electric power of 0.54 dBm in level-1 PR power (1B21) product. The level-2 rainfall (2A25) product is produced from the 1B21 product via products of level-1 radar reflectivity (1C21), level-2 surface cross section (2A21), and rain characteristics (2A23). The simulated data are generated from June 2009 to December 2010 and quantitatively assessed for the PR H/W change. The simulated data produce a decrease in rain frequency and tend to mitigate the discontinuity caused by the PR H/W change. Semi-global (35S-35N) precipitation amount derived from the simulated data in 2010 decreased by about 1 %, compared with the original data. Oceanic precipitation is uniformly decreased, while land precipitation regionally decreases and increases in spite of the decrease in rain frequency. Regional dependence of land precipitation change will be examined focusing on changes of path-integrated-attenuation and rain type classification.
2 非会員 Ph.D (独)情報通信研究機構 (〒184-8795 東京都小金井市貫井北町4-2-1) 3 正会員 修士(工学) 東京大学生産技術研究所 (〒153-8505 東京都目黒区駒場4... more 2 非会員 Ph.D (独)情報通信研究機構 (〒184-8795 東京都小金井市貫井北町4-2-1) 3 正会員 修士(工学) 東京大学生産技術研究所 (〒153-8505 東京都目黒区駒場4-6-1) 4 正会員 博士(工学) 東京大学生産技術研究所 (〒153-8505 東京都目黒区駒場4-6-1) The latest version of the TRMM (Tropical Rainfall Measuring Mission)/PR (Precipitation Radar) standard product (Version 7; V7) was recently released. This study focuses on heavy rain rate estimated in V7, which are more frequent than in the previous version (Version 6; V6). Surface reference technique is crucial for attenuation correction particularly of heavy rainfall, and becomes more reliable in V7, mainly because of ensemble of multiple SRT methods. Though the accuracy of clutter detection and the validity of Z-R relations are carefully examined, there are still possible rain estimates with extremely heavy rate of more than 300 mm/h. As hourly rain rate, 300 mm/h should be unexceptional, but the time scale of PR measurement may be shorter than 1 hour and these extremely heavy rain rate estimates should be investigated considering the time scale. Relations between heavy rain rates and surface temperature are analyzed with V7 and surface measurements. 99% rain rates in V7 generally increase with the increase of daily surface temperature, though daily rain amount by gauges tends to decrease when daily surface temperature becomes higher than 25 o C, which implies different time scales between PR and gauge measurements.
The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (G... more The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite was developed by the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). GPM core observatory was successfully launched by H-IIA launch vehicle on Feb 28, 2014. JAXA is continuing DPR trend monitoring, calibration and validation operations to confirm that DPR keeps its function and performance on orbit. The results of DPR trend monitoring, calibration and validation showed that DPR kept its function and performance on orbit during the 3 years and 2 months prime mission period. JAXA confirmed the prime mission results of GPM/DPR total system achieved the success criteria and the performance indicators. GPM/DPR moved to extended mission phase. JAXA conducted two types of scan pattern change test operations, KaPR-HS outer swath scan pattern and KuPR and KaPR wider swath scan. These useful data will help feasibility studies of the proposed KaPR scan pattern for the next DPR product version up and the future spaceborne radar development.
The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core s... more The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. JAXA and NICT developed the DPR through procurement. The configuration of precipitation measurement using active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core satellite is 65 degrees, and the nominal flight altitude is 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). Both KuPR and KaPR have almost the same design as TRMM PR. The DPR system design and performance were verified through the ground test. GPM core observatory was launched at 18:37:00 (UT) on February 27, 2014 successfully. DPR orbital check out was completed in May 2014. The results of orbital checkout show that DPR meets its specification on orbit. After completion of initial checkout, DPR started Normal Operations and Initial Calibration and Validation period was started. JAXA conducted internal calibrations, external calibrations and phase code changes to mitigate KuPR sidelobe clutter effect. JAXA evaluated these operations results and concluded that DPR data could go public. DPR products were released to the public on Sep. 2, 2014 and Normal Observation Operation period was started. JAXA is continuing DPR trend monitoring, calibration operations to confirm that DPR keeps its function and performance on orbit.
IEICE Transactions on Communications, Dec 25, 1995
... Footprints of Storms on the Sea in the JERS-1 SAR Image Toshio IGUCHI David ATLASKen'ich... more ... Footprints of Storms on the Sea in the JERS-1 SAR Image Toshio IGUCHI David ATLASKen'ichi OKAMOTO Akimasa SUMI Publication IEICE TRANSACTIONS on ... The outer boundary of the bright area has been found to be associated with the classical gust front. ...
... P162 Implication of Observed Vertical Profile of Drop Size Spectra in the Study of Dual-Frequ... more ... P162 Implication of Observed Vertical Profile of Drop Size Spectra in the Study of Dual-Frequency Radar Rain Retrievals. Adhikari Nanda B. NICT. 花土 弘 Hanado Hiroshi; JAXA. Takahashi Nobuhiro; NICT. Iguchi Toshio; NICT. Ohno Yuichi; NICT. Horie Hiroaki; NICT. ...
The Dual-frequency Precipitation Radar (DPR) that will be installed on the Global Precipitation M... more The Dual-frequency Precipitation Radar (DPR) that will be installed on the Global Precipitation Measurement (GPM) core satellite is being developed. The DPR consists of Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). The objectives of the DPR are to provide three-dimensional precipitation (rainfall and snowfall) structure over both ocean and land, and to improve the sensitivity and accuracy of the precipitation measurement. Both KuPR and KaPR have almost the same design as TRMM PR, which includes 128-element phased array antenna, SSPA, LNA, PHS, and so on. The minimum detectable rainfall rate will be improved to 0.2 mm/hr by KaPR. Accurate rainfall estimates will be provided by a dual-frequency algorithm using the matched beam data observed by KuPR and KaPR. KuPR KaPR GMI KuPR KaPR GMI DPR (Dual-frequency precipitation radar) consists of KuPR (13.6GHz radar) and KaPR (35.5GHz radar)
First, we found that the wind over Sakai is basically west direction at all height every year. Se... more First, we found that the wind over Sakai is basically west direction at all height every year. Second, in summer season the wind velocity is basically weak and its direction is west ward, but in winter season the strong west ward wind is observed. Third, the unique diurnal variation is observed in this area. Above characteristics are useful for the improvements of the accuracy of a atmospheric mesoscale model and an environment impact assessment.
ABSTRACT The next-generation Global Precipitation Measurement (GPM) mission core satellite will h... more ABSTRACT The next-generation Global Precipitation Measurement (GPM) mission core satellite will have a better capability of detecting light rain and falling snow in middle and high latitudes via a dual-frequency radar (i.e., the GPM dual-frequency precipitation radar or DPR) and a multi-frequency radiometer (i.e., the GPM Microwave Imager or GMI). This improvement requires more complex rainfall algorithms that can handle multi-sensor and multi- frequency signals of warm/cold/mixed rain over land/ocean in the Tropics as well as high latitudes. To facilitate such algorithm development, this project aims to develop a Synthetic GPM Simulator composed of a unified GPM instrument simulator (forward model) and CRM-simulation database. The Synthetic GPM Simulator forward model will be built upon the existing multi-sensor satellite simulator, the Goddard Satellite Data Simulator Unit (SDSU). We will simulate and constrains numerical simulations of the Cloud-Resolving Model with Spectra-bin Microphysics (CRM-SBM) through evaluating micro and macrohysics against GPM Ground-Validation (GV) observations, including Canadian CloudSat/CALIPSO Validation Project (C3VP) in Canada, Light Precipitation Validation Experiment (LPVEx) in Finland, and upcoming Midlatitude Convective Clouds Experiment (MC3E) in US.
The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core s... more The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite is being developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA is developing the satellite bus and the GPM microwave radiometer (GMI), and JAXA and NICT are developing the DPR. JAXA and NICT are developing the DPR through procurement. The contract for DPR is NEC TOSHIBA Space Systems, Ltd. The proto-flight test for DPR started in November 2010. The status of proto-flight test of DPR will be presented.
Dual-frequency Precipitation Radar (DPR) on the core satellite of Global Precipitation Measuremen... more Dual-frequency Precipitation Radar (DPR) on the core satellite of Global Precipitation Measurement (GPM) mission has changed its scan pattern in May 2018. As the high-sensitivity measurement of KaPR has been moved to the outer swath from the inner swath, all pixels are measured by both KuPR and KaPR after the scan pattern change. Experimental product (DPR Version 06X; V6X in short) for the new scan pattern applies dual-frequency algorithm for the outer swath. In this study, precipitation rates and other outputs of V6X are analyzed. Dual-frequency algorithm of V6X shows strong incident angle dependence of precipitation rates in the outer swath.
The GPM core satellite is scheduled to be launched on February 28, 2014. It carries the Dual-Freq... more The GPM core satellite is scheduled to be launched on February 28, 2014. It carries the Dual-Frequency Precipitation Radar (DPR) developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT), which consists of two radars: Ku-band precipitation radar (KuPR, 13.6 GHz) and Ka-band radar (KaPR, 35.5 GHz). NICT is planning the GPM/DPR onboard calibration experiment at NICT Koganei. The beam matching of two radars will be evaluated. NICT is also planning the post-launch ground validation (product validation) experiment at two locations, NICT Kobe (NICT Advanced ICT Research Institute) and NICT Okinawa (Okinawa Electromagnetic Technology Center). NICT is developing two X-band phased array radars (PANDA: Phased Array radar Network DAta system) and will install at NICT Kobe and Okinawa. PANDA can scan three-dimensionally in thirty seconds. We can compare the radar directly and simultaneously. At NICT Okinawa, the C-band polarimetric Doppler radar (COBRA) is also installed. The differential reflectivity (ZDR) can be used to validate the rain drop size distribution parameter (D 0). The cross-correlation coefficient (ρHV) can be used to validate the melting layer flag. Using the ground-based rain drop size measurements, the two-dimensional Video disdtrometer (2DVD), Joss-type disdrometer, and Laser Optical disdrometr (Parsivel), and so on, the characteristics of DSD itself are analyzed and the k-Z relationship is estimated for evaluation and improvement of the GPM/DPR algorithm.
(NICT), we promote advanced research and development of remote sensing technology, to reduce the ... more (NICT), we promote advanced research and development of remote sensing technology, to reduce the damage of severe weather disasters caused by localized heavy rainfalls or tornadoes. An industry-academia-government team consisting of Toshiba, Osaka University, and NICT developed one-dimensional phased array weather radar (PAWR) that it is possible to seamless 3D observation in 10 ? 30 seconds. In May 2012, we installed PAWR at Osaka University Suita Campus, and started test observation. From the observation, a first echo appeared in an isolated cumulonimbus cloud was falling to the ground for about 10 minutes. In order to predict the generation point of the cumulonimbus cloud, we need other data which includes wind fields before cloud generation, distributions of water vapor and aerosol, and so on. For that reason, we develop a sensor fusion system with PAWR, Doppler lidar, and others. We install the systems to both NICT Advanced ICT Research Institute (Iwaoka, Nishi-ku, Kobe, Hyogo) and NICT Okinawa Electromagnetic Technology Center (Onna, Kunigami, Okinawa), and install the network data system to NICT headquarters (Koganei, Tokyo). The sensor fusion system consists of the PAWR antenna in a radome installed on the roof of a 20 m tower, Doppler lidar (Leosphere 400s) on the deck at the height of 15 m of the tower, microwave radiometer to measure water vapor, and sky-radiometer to measure aerosol. Also, temperature, humidity, wind speed components (u, v, w), pressure, rainfall amount, radiation budget, and cloud images (4 directions and whole sky) are measured. All sensors are connected by network for remote operation and automatic data acquisition. The observation data are transferred in real-time through the fast network lines (JGN-X) from Kobe and Okinawa to Koganei for data processing to make a composite map, and so on. The processing data are displayed on a big 4K display TV, and are published using a web server. We will start test observation after the system completion in March, 2014. At NICT, we also promote research and development of network data system using advanced ICT for big-data processing, transfer, visualization. We give this system a nickname of PANDA: Phased Array weather radar and Doppler lidar Network fusion DAta system, and will publish the data from http://panda.nict.go.jp/.
Precipitation observation by the Tropical Rainfall Measuring Mission' s (TRMM' s) Precipitation R... more Precipitation observation by the Tropical Rainfall Measuring Mission' s (TRMM' s) Precipitation Radar (PR) has lasted for almost 17 years. On February 28, 2014, the core satellite of the Global Precipitation Measurement (GPM) mission was launched, and the GPM Dual-frequency Precipitation Radar (DPR) started providing precipitation data succeeding the TRMM PR observation. PR and DPR not only estimate precipitation accurately both over land and the oceans but also provide information to derive precipitation characteristics (e.g., rain top height and rain vertical profile). Homogeneity of long-term PR/DPR data will be essential to study the water cycle change related to the decadal climate variability. In this study, we aim to develop a precipitation climate data from 17-year PR data. The PR data have discontinuities in quality due to the boost of the TRMM satellite altitude in August 2001 and the PR hardware (H/W) change in June 2009. In this paper, PR data are adjusted to mitigate the discontinuity of the PR H/W change. The observation of PR temporary stopped on May 29, 2009. The PR H/W changed from Aside to B-side and the B-side observation has started since June 19, 2009, which causes the drop of noise power. The difference in noise power between 2008 and 2010 is obtained as a decrease of 0.54 dBm. This change affects a minimum detection of weak rain by PR. In the current study, the B-side PR data are adjusted to simulate the data with the characteristics of Aside PR. The simulated data are created with the additional electric power of 0.54 dBm in level-1 PR power (1B21) product. The level-2 rainfall (2A25) product is produced from the 1B21 product via products of level-1 radar reflectivity (1C21), level-2 surface cross section (2A21), and rain characteristics (2A23). The simulated data are generated from June 2009 to December 2010 and quantitatively assessed for the PR H/W change. The simulated data produce a decrease in rain frequency and tend to mitigate the discontinuity caused by the PR H/W change. Semi-global (35S-35N) precipitation amount derived from the simulated data in 2010 decreased by about 1 %, compared with the original data. Oceanic precipitation is uniformly decreased, while land precipitation regionally decreases and increases in spite of the decrease in rain frequency. Regional dependence of land precipitation change will be examined focusing on changes of path-integrated-attenuation and rain type classification.
2 非会員 Ph.D (独)情報通信研究機構 (〒184-8795 東京都小金井市貫井北町4-2-1) 3 正会員 修士(工学) 東京大学生産技術研究所 (〒153-8505 東京都目黒区駒場4... more 2 非会員 Ph.D (独)情報通信研究機構 (〒184-8795 東京都小金井市貫井北町4-2-1) 3 正会員 修士(工学) 東京大学生産技術研究所 (〒153-8505 東京都目黒区駒場4-6-1) 4 正会員 博士(工学) 東京大学生産技術研究所 (〒153-8505 東京都目黒区駒場4-6-1) The latest version of the TRMM (Tropical Rainfall Measuring Mission)/PR (Precipitation Radar) standard product (Version 7; V7) was recently released. This study focuses on heavy rain rate estimated in V7, which are more frequent than in the previous version (Version 6; V6). Surface reference technique is crucial for attenuation correction particularly of heavy rainfall, and becomes more reliable in V7, mainly because of ensemble of multiple SRT methods. Though the accuracy of clutter detection and the validity of Z-R relations are carefully examined, there are still possible rain estimates with extremely heavy rate of more than 300 mm/h. As hourly rain rate, 300 mm/h should be unexceptional, but the time scale of PR measurement may be shorter than 1 hour and these extremely heavy rain rate estimates should be investigated considering the time scale. Relations between heavy rain rates and surface temperature are analyzed with V7 and surface measurements. 99% rain rates in V7 generally increase with the increase of daily surface temperature, though daily rain amount by gauges tends to decrease when daily surface temperature becomes higher than 25 o C, which implies different time scales between PR and gauge measurements.
The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (G... more The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite was developed by the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). GPM core observatory was successfully launched by H-IIA launch vehicle on Feb 28, 2014. JAXA is continuing DPR trend monitoring, calibration and validation operations to confirm that DPR keeps its function and performance on orbit. The results of DPR trend monitoring, calibration and validation showed that DPR kept its function and performance on orbit during the 3 years and 2 months prime mission period. JAXA confirmed the prime mission results of GPM/DPR total system achieved the success criteria and the performance indicators. GPM/DPR moved to extended mission phase. JAXA conducted two types of scan pattern change test operations, KaPR-HS outer swath scan pattern and KuPR and KaPR wider swath scan. These useful data will help feasibility studies of the proposed KaPR scan pattern for the next DPR product version up and the future spaceborne radar development.
The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core s... more The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. JAXA and NICT developed the DPR through procurement. The configuration of precipitation measurement using active radar and a passive radiometer is similar to TRMM. The major difference is that DPR is used in GPM instead of the precipitation radar (PR) in TRMM. The inclination of the core satellite is 65 degrees, and the nominal flight altitude is 407 km. The non-sun-synchronous circular orbit is necessary for measuring the diurnal change of rainfall similarly to TRMM. The DPR consists of two radars, which are Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). Both KuPR and KaPR have almost the same design as TRMM PR. The DPR system design and performance were verified through the ground test. GPM core observatory was launched at 18:37:00 (UT) on February 27, 2014 successfully. DPR orbital check out was completed in May 2014. The results of orbital checkout show that DPR meets its specification on orbit. After completion of initial checkout, DPR started Normal Operations and Initial Calibration and Validation period was started. JAXA conducted internal calibrations, external calibrations and phase code changes to mitigate KuPR sidelobe clutter effect. JAXA evaluated these operations results and concluded that DPR data could go public. DPR products were released to the public on Sep. 2, 2014 and Normal Observation Operation period was started. JAXA is continuing DPR trend monitoring, calibration operations to confirm that DPR keeps its function and performance on orbit.
IEICE Transactions on Communications, Dec 25, 1995
... Footprints of Storms on the Sea in the JERS-1 SAR Image Toshio IGUCHI David ATLASKen'ich... more ... Footprints of Storms on the Sea in the JERS-1 SAR Image Toshio IGUCHI David ATLASKen'ichi OKAMOTO Akimasa SUMI Publication IEICE TRANSACTIONS on ... The outer boundary of the bright area has been found to be associated with the classical gust front. ...
... P162 Implication of Observed Vertical Profile of Drop Size Spectra in the Study of Dual-Frequ... more ... P162 Implication of Observed Vertical Profile of Drop Size Spectra in the Study of Dual-Frequency Radar Rain Retrievals. Adhikari Nanda B. NICT. 花土 弘 Hanado Hiroshi; JAXA. Takahashi Nobuhiro; NICT. Iguchi Toshio; NICT. Ohno Yuichi; NICT. Horie Hiroaki; NICT. ...
The Dual-frequency Precipitation Radar (DPR) that will be installed on the Global Precipitation M... more The Dual-frequency Precipitation Radar (DPR) that will be installed on the Global Precipitation Measurement (GPM) core satellite is being developed. The DPR consists of Ku-band (13.6 GHz) precipitation radar (KuPR) and Ka-band (35.5 GHz) precipitation radar (KaPR). The objectives of the DPR are to provide three-dimensional precipitation (rainfall and snowfall) structure over both ocean and land, and to improve the sensitivity and accuracy of the precipitation measurement. Both KuPR and KaPR have almost the same design as TRMM PR, which includes 128-element phased array antenna, SSPA, LNA, PHS, and so on. The minimum detectable rainfall rate will be improved to 0.2 mm/hr by KaPR. Accurate rainfall estimates will be provided by a dual-frequency algorithm using the matched beam data observed by KuPR and KaPR. KuPR KaPR GMI KuPR KaPR GMI DPR (Dual-frequency precipitation radar) consists of KuPR (13.6GHz radar) and KaPR (35.5GHz radar)
First, we found that the wind over Sakai is basically west direction at all height every year. Se... more First, we found that the wind over Sakai is basically west direction at all height every year. Second, in summer season the wind velocity is basically weak and its direction is west ward, but in winter season the strong west ward wind is observed. Third, the unique diurnal variation is observed in this area. Above characteristics are useful for the improvements of the accuracy of a atmospheric mesoscale model and an environment impact assessment.
ABSTRACT The next-generation Global Precipitation Measurement (GPM) mission core satellite will h... more ABSTRACT The next-generation Global Precipitation Measurement (GPM) mission core satellite will have a better capability of detecting light rain and falling snow in middle and high latitudes via a dual-frequency radar (i.e., the GPM dual-frequency precipitation radar or DPR) and a multi-frequency radiometer (i.e., the GPM Microwave Imager or GMI). This improvement requires more complex rainfall algorithms that can handle multi-sensor and multi- frequency signals of warm/cold/mixed rain over land/ocean in the Tropics as well as high latitudes. To facilitate such algorithm development, this project aims to develop a Synthetic GPM Simulator composed of a unified GPM instrument simulator (forward model) and CRM-simulation database. The Synthetic GPM Simulator forward model will be built upon the existing multi-sensor satellite simulator, the Goddard Satellite Data Simulator Unit (SDSU). We will simulate and constrains numerical simulations of the Cloud-Resolving Model with Spectra-bin Microphysics (CRM-SBM) through evaluating micro and macrohysics against GPM Ground-Validation (GV) observations, including Canadian CloudSat/CALIPSO Validation Project (C3VP) in Canada, Light Precipitation Validation Experiment (LPVEx) in Finland, and upcoming Midlatitude Convective Clouds Experiment (MC3E) in US.
The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core s... more The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite is being developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The GPM is a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM). The objectives of the GPM mission are to observe global precipitation more frequently and accurately than TRMM. The frequent precipitation measurement about every three hours will be achieved by some constellation satellites with microwave radiometers (MWRs) or microwave sounders (MWSs), which will be developed by various countries. The accurate measurement of precipitation in mid-high latitudes will be achieved by the DPR. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA is developing the satellite bus and the GPM microwave radiometer (GMI), and JAXA and NICT are developing the DPR. JAXA and NICT are developing the DPR through procurement. The contract for DPR is NEC TOSHIBA Space Systems, Ltd. The proto-flight test for DPR started in November 2010. The status of proto-flight test of DPR will be presented.
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Papers by Toshio Iguchi