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The first X-band dual polarized phased array weather radar (DP-PAWR), which simultaneously transmits pulses of horizontal and vertical polarized radiation, was developed and installed at Saitama University, Japan, in December 2017. The DP-PAWR uses mechanical and electronic scanning at azimuth and elevation angles, respectively. It provides polarimetric precipitation measurements via 3-D volume scanning with an update rate between 10 and 60 s, for a range of up to 80 km. Here, we describe the initial DP-PAWR observation results. To evaluate the DP-PAWR observation accuracy, we compared the observational data with radar variables derived from Parsivel disdrometer data. In comparison with the disdrometer, the relative observation accuracy for the DP-PAWR radar reflectively factor had a standard deviation of 1.1 dB and mean value of 0.4 dB. We also conducted detailed observations of a developing thunderstorm using a specific differential phase ( $K_{\mathrm {dp}}$ ) column, focusing on the $K_{\mathrm {dp}}$ core during the storm. The $K_{\mathrm {dp}}$ core movements provided useful information about the convection flow during the storm.

Under the Japanese Cross Strategic Innovation Promotion Program (SIP), studies are conducted to perform very short-term predictions of local torrential rains based on a new multi-parameter phased-array weather radar (MP-PAWR) and deep neural networks (DNNs). The association of the two methods is expected to overcome the limitations of the conventional rains observation systems and numerical models that are not well suited to handle the rapid non-linear processes inherent in heavy convective rains. The unique spatio-temporal resolution of the observations allows us to train supervised DNNs to extrapolate the fast evolution of 3D convective cells. We compared two DNNs (CLM3D and CGRU3D) designed to fully exploit the information in the vertical dimension. Both methods use new techniques involving spatial convolutions in temporal recurrent iterations such as Long Short-Term Memory (LSTM) or Gated Recurrent Units (GRU) ones. The core of CLM3D is a stack of convLTSM2D layers, each of which is applied to a single altitude. CGRU3D uses a multilayer encoderdecoder with convGRU3D layers, each layer is associated with a size of 3D spatial features. Forecasts with a lead-time of 10 min at an altitude of 600 m with a horizontal resolution of about 500 m are compared. The models are tested with different types of heavy precipitation: localized short-lived rains on July 24, 2018 and wide-spread ones on the 29 of the same month. The models are evaluated with respect to a 3D linear advection nowcast model (OF3D) and a persistent one. We found that the DNN and OF3D models perform better on July 24 with similar scores that are significantly higher than those of the persistent model. Considering all rain events, critical success indexes (CSI) of 0.62, 0.53, 0.55 are found for CGRU3D, CLM3D and OF3D, respectively, and 0.43 for the persistent model. Regarding only heavy precipitation, the CSIs show a great variability between 0 and 0.4 on the predictions made that day. These results clearly illustrate the great challenge of nowcasting heavy precipitation. On July 29, none of the models have significantly higher scores than those obtained with the persistent nowcast. The interesting result of this study is that the two DNNs show similar nowcasting skills whatever the intensity and the type of rain, and this despite their architectures and training strategies being different. This may indicate that optimizing the tunning of the hyperpameters and the training dataset could not bring significant improvements and, the key, could be by feeding the models with more comprehensive information on the atmospheric state.

This study is about the development of a deep neural network to make very short-term predictions of torrential rains at the urban scale (meso-γ). The new polarimetric Phased Array Weather Radar (MP-PAWR) operating at Saitama (Japan) since 2018 is used. Thanks to the unique spatio-temporal resolution of the measurements, the precursors of torrential rains are detected aloft more than 20 minutes before the rain occurs. With this information, we aim at the prediction of surface precipitation with a lead time of 20 min, a horizontal resolution better than 500 m within a radius of 25 km around the instrument. Two supervised neural networks are considered to extrapolate radar reflectivity (ZH) at the altitude of 600 m. The first model (model-1) is based on a technique developed for mesoscale predictions from observations at a single altitude. It uses horizontal (2D) convolutions in gated recurrent time iterations and a multilayer encoder-decoder (EC/DC) architecture. The technique is adapted to consider 3 radar parameters and 11 altitudes up to 10 km, in the same way as RBG channels in video analysis. The second model (model-2) uses similar architecture but with 3D spatial convolutions to properly describe the vertical motions between adjacent layers. The input to the models consist in 20 min long time series of ZH, Doppler velocity and differential reflectivity observations (30 sec sampling). The models are trained using all the rain events observed between August and October 2018, and are assessed using local heavy rains observed over a period of 1-hour on July, 24, 2018. The beginning of the rain is first predicted with a lead time of about 5 min, and its evolution is fairly well reproduced to lead times up to about 10 min. Results quickly degrades for longer lead times. We found that a deeper network with 4 layers EC/DC gives better 20 min predictions than a model with 3 layers, but final results were not yet obtained at the time of writing. Regarding lead-times of 10 min, model-2 gives critical success indexes (CSIs) of 0.60 and 0.40 for pixels with ZH> 10 dBZ and 37 dBZ, which is comparable or better than results presented in other studies. For lead-times of 20 min, CSIs dropped to 0.28 and 0.10, respectively, and no other studies was found for comparison. Model-1 clearly shows poorer performance, especially for high ZH. However, this approach demands much less calculations and the training lasts only 2 weeks long, namely half of the time spent for model-2. Therefore, it is worth further studying both approaches and potential improvements are discussed.

For the spaceborne precipitation radars, since the surface echoes are very strong, the clutter echoes caused by the antenna sidelobe mask the echoes of light precipitation even if the low sidelobe antenna is designed. This study develops a method of the clutter removal for the spaceborne precipitation radars to mitigate the misjudgment of the light precipitation detection. The radar data of the Dual-frequency precipitation radar (DPR) onboard the Global Precipitation Measurement mission's (GPM 's) core satellite and the Precipitation Radar (PR) onboard the Tropical Rainfall Measuring Mission (TRMM) satellite are analyzed to construct those clutter databases. Once the databases are created, the magnitude of the clutter echoes is estimated and its contribution is subtracted from the observed echo power. When the clutter removal developed in this study are applied, the residual clutter signals are mitigated compared with the clutter removal adopted in version 06 processing.

This paper is an overview of a project concerned with “Early warning for torrential rainfall/tornado” under “Enhancement of Societal Resiliency against Natural Disasters,” which is one of eleven themes of the SIP (Cross-ministerial Strategic Innovation Promotion Program under the Council for Science, Technology and Innovation, the Cabinet Office, Government of Japan). The characteristics of the project are the development of a multi-parameter phased array weather radar (MP-PAWR) that enables the accomplishment of an accurate three-dimensional model of precipitation over 30 s within a 60 km radius. Various products developed ducts using MP-PAWR and other observations, and numerical predictions, are also discussed, with a demonstration experiment to provide early warnings for torrential rainfall and related disasters. For end users such as local governments and general citizens, the final goal of this project is the social implementation of these products.

An estimation method for specific attenuation and equivalent radar reflectivity in the melting layer using a dual Ka-band radar system was studied. The system consists of two identically designed Ka-radars. When a precipitation system comes between the two radars, the radars observe the system from opposite directions. The radar applies the frequency-modulated continuous-wave type and is designed for the measurement of the scattering characteristics of precipitation particles. The precipitation echoes suffer from rain attenuation. The reduction due to rain attenuation symmetrically appears in both radar echoes. By differentiating averaged measured radar reflectivity with range, the specific attenuation can be estimated. After obtaining the specific attenuation, equivalent radar reflectivity is estimated. In the melting layer, specific attenuation and the equivalent radar reflectivity vary largely along the radio path, and the estimated specific attenuation is very sensitive to the setup configuration of the experiment. The accuracy of the estimated specific attenuation was found to depend on the curvature, that is, the doubly differentiated value of the equivalent radar reflectivity with respect to range and the distance for the differentiation. The measurement system and actual procedure for the data analysis are also described.

Special experiments using the Precipitation Radar (PR) onboard the Tropical Rainfall Measuring Mission satellite during descent after the orbital maintenance fuel was depleted are reported in this paper. In these special observation experiments, a 90 deg yaw maneuver experiment, a wide swath width experiment, and the dense sampling experiments were carried out. The key operation of these experiments was a large change in the phase shifter settings of the transmitter and receiver, which was not tested before or after the launch. In addition, the 90 deg yaw experiment required the special operation of the satellite, whereas the other two experiments were implemented by changing only the PR operation. During the experiments, the PR was operated, and the expected data were obtained. The preliminary results suggest the possibility of future radar observation from space, and the results of these experiments will be utilized as basic data to improve the algorithm of the dual-frequency PR onboard the Global Precipitation Measurement mission core satellite and the design of future spaceborne PRs., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: PA1610016000

There is insufficient understanding of backscattering and attenuation for the radiowave remote sensing of snow because ground measurements of snow in the Ka-band are limited. This study estimates the equivalent radar reflectivity factor $(Z_e)$ and specific attenuation $(k)$ of snow using a dual Ka-band radar (KaR) system comprising two identical Ka-band instruments. To evaluate the estimations, estimated $k{-}Z_e$ plots of rain events are compared with plots estimated from the raindrop size distribution. The two $k{-}Z_e$ plots have similar power-law relations. In contrast, $k{-}Z_e$ plots of snow have complex tendencies. Among snow events, the tendencies of $k{-}Z_e$ relations depend on surface temperature. When surface temperature exceeds 0 °C during snow events, $k{-}Z_e$ data are scattered and there are $k$ values higher than those of rain. In contrast, when surface temperature is below 0 °C during snow events, both $k$ and $Z_e$ are low and the $k{-}Z_e$ plots show no relation. In the former (latter) cases, wet (dry) snow is probably dominant. The differences in $k{-}Z_e$ relations of snow are attributed to the differences in backscattering and attenuation characteristics between wet and dry snow. To confirm the existence of wet/dry snow, snow particle data obtained using a two-dimensional video disdrometer on the ground are analyzed. Velocity–size distributions are clearly different in wet- and dry-snow cases. For dry-snow cases, snow particles of dry snow and graupel occasionally coexisted.

Most of space-based observing systems make water-vapor- and temperature-related measurements, while spacebased observing systems for wind measurement is limited. The current passive space-based observing systems for wind measurement has a large coverage area and high temporal and horizontal resolutions but has a low vertical resolution. The World Meteorological Organization (WMO) wants to develop space-based wind profiling systems. A Doppler Wind Lidar (DWL) is a useful and power technology for wind measurement and it can be designed as compact mobile, airborne, and space-based systems. DWL would provide us with a wind profile having high vertical resolution, low bias, and good precision, and it is necessary to fill the gap of current observations. The National Institute of Information and Communications Technology (NICT) is developing a single-frequency high-energy Tm,Ho:YLF laser, 2-μm key technology and instrument for a future space-based coherent DWL. We demonstrated the Tm,Ho:YLF laser producing a pulse energy of 125 mJ operating at 30 Hz meeting requirements for the future spacebased coherent DWL. In the paper, we will describe recent progress at NICT.

Algorithms for estimating precipitation rates from spaceborne radar observations of apparent radar reflectivity depend on attenuation correction procedures. The algorithm suite for the Ku-band precipitation radar aboard the Tropical Rainfall Measuring Mission satellite is one such example. The well-known problem of nonuniform beam filling is a source of error in the estimates, especially in regions where intense deep convection occurs. The error is caused by unresolved horizontal variability in precipitation characteristics such as specific attenuation, rain rate, and effective reflectivity factor. This paper proposes the use of vertical decorrelation for correcting the nonuniform beam filling error developed under the assumption of a perfect vertical correlation. Empirical tests conducted using ground-based radar observations in the current simulation study show that decorrelation effects are evident in tilted convective cells. However, the problem of obtaining reasonable estimates of a governing parameter from the satellite data remains unresolved.

We carried out the intensive observation for the GPM/DPR ground validation at Mt. Zao during 2014–2015 winter season, targeting the melting layer. For the better understanding of microphysics in the melting layer, we developed Ground-based Particle Image and Mass Measurement System (G-PIMMS). It can capture particle images by CCD cameras and measure particle weight by the electronic balance. G-PIMMSs were installed at two different altitudes on the hillside of Mt. Zao between two confronting Ka radar sites. We often experienced sleet or wet snow on the ground in early/late winter season, and succeeded in observation of the melting layer. Rain and snow, including sleet, were discriminated at 1.5–2.1°C in wet-bulb temperature. It was also found the density of precipitation changing with temperature between 0°C and 2°C.

During the rainy season over the East China Sea, convective rainfalls often show melting layer (ML) characteristics in polarimetric radar variables. In this research, the appearance ratio of the ML (the ratio of rainfall area accompanied by polarimetric ML signatures) and the variation in height of the level of the ML signature maximum (MLSM level; defined by the level of the ρhv minimum in the ML) in a convective rainfall region in a rainfall system over the East China Sea observed on 2 June 2006 were studied using C-band polarimetric radar (COBRA). For this analysis, a method of rainfall type classification that evaluates the presence of an ML in addition to providing conventional convective–stratiform classification using range–height indicator (RHI) observation data was developed. This rainfall type classification includes two steps: conventional convective–stratiform separation using the horizontal distribution of Zh at 2-km altitude, and ML detection using the vertical profile of ρhv at each horizontal grid point. Using a combination of these two classifications, the following four rainfall types were identified: 1) convective rainfall with an ML, 2) convective rainfall with no ML, 3) stratiform rainfall with an ML, and 4) stratiform rainfall with no ML. An ML was detected in 53.9% of the convective region in the rainfall system. Using the same definition, an ML was detected in 83.1% of the stratiform region. The ML in the convective region showed a marked decrease in ρhv coincident with an increase in ZDR around the ambient 0°C level, as did that in the stratiform region. Melting aggregated snow was the likely cause of the ML signature in the convective region. The average height of the MLSM level in the convective region was 4.64 km, which is 0.46 km higher than that in the stratiform region (4.18 km) and 0.27 km higher than the ambient 0°C level (4.37 km).

A new videosonde receiving system consisting of two receiv- ing antennas for a set of videosonde and GPS radiosonde has been developed. The antenna for the videosondes is controlled by a GPS slave method, in which the antenna elevation and azimuth are processed every second using GPS location data obtained from a GPS radiosonde attached to the videosonde. The results of the first experimental flight conducted in Okinawa as part of a synchronized observation campaign of a C-band polarimetric radar and videosondes reveal successful reception of clear images of precipitation particles in clouds.

Improvement of quantitative precipitation estimation (QPE) is one of the primary benefits providedbypolarization radars. Ministryof Land, Infrastructure and Transportation Japan (MLIT) put Shakadakeoperational Cband Radar to practical use in1992. However, large improvement hadnotbeenrealizedbecause of its initial technical stage.Under these circumstances, first, this paper compares the performance of the conventional R (ZHH) relation and three polarimetric relations, which are R (ZHH, ZDR), R (KDP), R (KDP, ZDR) . At lower rainrates, the combinationof KDP and ZDR is less efficient because KDP becomes noisy. Next in order to improveQPE, a few combinations of estimation equations for operational purpose is proposed, considering thecharacteristic ofthose relations. Also validations with some other algorithms are conducted. As a result, the proposed algorithms improve the estimationof hourly rainfall and accumulated total rainfall.

This paper documents the production and validation of retrieved rainfall data obtained from satellite-borne microwave radiometers by the Global Satellite Mapping of Precipitation (GSMaP) Project. Using various attributes of precipitation derived from Tropical Rainfall Measuring Mission (TRMM) satellite data, the GSMaP has implemented hydrometeor profiles derived from Precipitation Radar (PR), statistical rain/no-rain classification, and scattering algorithms using polarization-corrected temperatures (PCTs) at 85.5 and 37 GHz. Combined scattering-based surface rainfalls are computed depending on rainfall intensities. PCT85 is not used for stronger rainfalls, because strong depressions of PCT85 are related to tall precipitation-top heights. Therefore, for stronger rainfalls, PCT37 is used, with PCT85 used for weaker rainfalls. With the suspiciously strong rainfalls retrieved from PCT85 deleted, the combined rainfalls correspond well to the PR rain rates over land. The GSMaP algorithm for the TRMM Microwave Imager (TMI) is validated using the TRMM PR, ground radar [Kwajalein (KWAJ) radar and COBRA], and Radar Automated Meteorological Data Acquisition System (AMeDAS) precipitation analysis (RA). Monthly surface rainfalls retrieved from six microwave radiometers (GSMaP_MWR) are compared with the gauge-based dataset. Rain rates retrieved from the TMI (GSMaP_TMI) are in better agreement with the PR estimates over land everywhere except over tropical Africa in the boreal summer. Validation results of the KWAJ radar and COBRA show a good linear relationship for instantaneous rainfall rates, while validation around Japan using the RA shows a good relationship in the warm season. Poor results, connected to weak-precipitation cases, are found in the cold season around Japan.

Dual polarimetric radar has been developed and partly utilizedinmeteorology and hydrology in these twenty years because of its potential ability in estimating drop size distribution (DSD) and in discriminating precipitation type. Ministryof Infrastructure, Land and Transportation (MILT) in Japan put Shakadake operational C band Radar to practical use in 1992. However, large improvement had not been realized because of its initial technical stage. Under these circumstances, this study investigates observation precision of the latest C band polarimetric radar for promoting replacement of Japanese operational radars into operational polarimetric radars. As results, this study shows ZHH ZDR and KDP observed bythe polarization radar well fit to non-parametricallycomputed ZHH, ZDR and KDP using observed DSD, respectively. Also, this study shows “Radar observed ZDR-Dm of observed DSD” relation is consistent with observed DSD. Especially, KDP, which is free from attenuation problem, is suitable to estimate the strong rainfall. Parameter from the polarimetric radar has high possibility to improve real-time rainfall estimation.

The vertical profile of raindrop size distribution (DSD) is important for understanding rain processes. To improve the accuracy of rainfall intensity observed by precipitation radar and microwave radiometers carried on satellites, the information on the vertical profile of DSD is also important. The purpose of this study is to develop a database of DSD for the satellites precipitation retrieval by using a 400MHz-band wind profiler and COBRA (CRL Okinawa Bistatic polarimetric Radar) for various kinds of hydrometer (rain, snow, and mix phase). A new algorithm is proposed above the melting layer. As a result, in the case that the spectrum peak of air motion is difficult to be found from the observed Doppler spectrum above the melting layer, it is possible that DSD can be estimated by the proposed algorithm.

The Tropical Rainfall Measuring Mission (TRMM) is a joint venture between the National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA). The TRMM spacecraft was launched on November 27, 1997. In August 2001, TRMM was boosted to a higher operational altitude of 402.5 km from the initial one of 350 km, to save fuel and extend the mission life. On July 8, 2014, a significant pressure drop during the orbit maintenance maneuver indicated the exhaustion of the onboard propellant. Precipitation Radar (PR) cannot collect the scientific meaningful data by the usual operation between the satellite altitudes of 402.5 km to 350 km. In order to obtain useful knowledge on development of future space borne precipitation radar, the special observation experiments were done during the TRMM satellite descending.

The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite was developed by JAXA and NICT. This paper describes mission objectives, technical performance, resource allocation, ground test results, orbital check out results and orbital operation status of the DPR. The DPR system PFT has completed in February 2012. GPM core spacecraft satellite system test has completed at NASA Goddard Space Flight Center 2013. GPM core observatory was shipped to JAXA Tanegashima Space Center, JAPAN and GPM core observatory was successfully launched by H-IIA launch vehicle on Feb 28, 2014. DPR orbital check out was completed in May 2014. DPR products released to the public on Sep. 2, 2014 and Normal Observation Operation period was started. The orbital operations status of DPR is reported in this paper.

This paper presents an inter-comparison of rainfall parameters (median volume diameter and rain rate) using C-band polarimetric radar, a 2D-video disdrometer and a 400 MHz profiler for the Baiu front event of 8-9 June 2005 in Okinawa, Japan. These instruments are part of the Okinawa Sub-Tropical Environment Remote Sensing Center, operated by the National Institute of Information and Communications Technology (NICT). The 2D-video disdrometer is used to derive the mean axis ratio of raindrops versus drop diameter, as well as the drop size distribution for the Baiu event. The data are then used to simulate various relations between polarimetric scattering parameters such as: specific attenuation (Ah), and specific differential attenuation (Adp), versus specific differential phase (Kdp) which are required to correct the measured reflectivity at horizontal polarization (Zh), and the differential reflectivity (Zdr) for rain attenuation. The 2D-video disdrometer data are also used to arrive at retrieval formulas for median volume diameter (D0) from radar Zdr and rain rate from radar Kdp.The intense Baiu event of 8-9 June 2005 was composed of heavy convective rain cells embedded in large areas of stratiform rain. The inter-comparison of D0 and rain rate (R) between instruments was conducted for 12 hours (03:00-07:00, 11:00-19:00 UTC on 8th June 2004). The C-band radar retrievals were found to be in excellent agreement with the 2D-video disdrometer for the entire period. The 400 MHz profiler retrievals of D0 and R were in good agreement with 2D-video disdrometer during the more steady rain periods, with more scatter observed during the heavier convective rain periods. These inter-comparisons demonstrate the accuracy of C-band polarimetric radar to retrieve important rainfall parameters, as well as the accurate correction for rain attenuation using differential propagation phase.

Thymidylate synthase (TS) is an enzyme that catalyzes an important DNA biosynthesis process. The gene expression of TS has not been reported in non-small-cell lung cancer (NSCLC) patients. To clarify the correlation between TS mRNA levels and clinicopathological features of NSCLC, we examined 70 Stage I and II NSCLC patients for intra-tumoral expression of TS using TaqMan reverse transcription polymerase chain reaction (RT-PCR) assay and immunohistochemistry methods. We also investigated the TS promoter 28 bp polymorphism in 48 cancer tissues using PCR amplification of genomic DNA. Lung cancer tissue showed higher TS mRNA levels than normal lung tissue (Mann-Whitney U-tests; p = 0.0020). Further, TS mRNA expression was correlated with immunohistochemical TS expression (p = 0.029). We obtained 2 different DNA fragments, which indicated triple-repeat (3R) and double-repeat (2R) type alleles. Cancer tissues with the 3R/3R genotype showed significantly higher TS mRNA levels as compared to those with other genotypes (p = 0.0019). The TS genotype was also correlated with immunohistochemical TS expression (χ2 test; p = 0.0079). The disease-free survival of the low TS mRNA level group was significantly better than those with high TS mRNA levels (log-rank test; p = 0.010), however, there were no significant differences found by immunohistochemical evaluation (p = 0.34) or TS genotype analysis (p = 0.11). A multivariate analysis revealed that high TS mRNA levels independently contributed to disease-free survival. The quantitation of TS mRNA levels is clinically more sensitive and useful for determining the prognosis of Stage I and II NSCLC patients than an immunohistochemical evaluation. © 2003 Wiley-Liss, Inc.

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 contract for DPR was awarded to NEC TOSHIBA Space Systems, Ltd. 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 flight altitude is about 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 development test and the proto flight test. DPR had handed over to NASA and integration of the DPR to the GPM core spacecraft had completed in May 2012. GPM core spacecraft satellite system test had completed in November 2013. The result of the satellite system test concerning to the DPR satisfied system requirements. GPM core observatory was shipped to Tanegashima Space Center, JAPAN and Launch Site Operations had started on November 2013 and 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 orbital check out and the initial calibration and validation operation result of DPR is reported.

Onboard calibration method of the Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core observatory, launched in February 2014, is described. The orbital check out status of DPR will be reported.

The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite was developed by JAXA and NICT. This paper describes mission objectives, technical performance, resource allocation, design, proto-flight test (PFT) of the DPR instrument, satellite system test including launch operations and orbital check out results of the DPR. The DPR system PFT has completed in February 2012. DPR has handed over to NASA and integration of the DPR to the GPM core spacecraft have completed in May 2012. GPM core spacecraft satellite system test has completed at NASA Goddard Space Flight Center. GPM core observatory was shipped to JAXA Tanegashima Space Center, JAPAN and Launch Site Operations has completed. GPM core observatory was successfully launched by H-IIA launch vehicle on Feb 28, 2014. DPR orbital check out had started in March 2014 and it was completed in May 2014. The orbital check out results of DPR is reported in this paper.

To improve the accuracy of the radar-estimated rainfall, we observe and analyze the vertical profile of the rain drop size distribution (DSD), then create a new formulation of vertical profile of DSD related to rainfall type and build up an algorithm for estimating ground rainfall using radar. Observation of the vertical profile of DSD is carried out by a vertical pointing VHF Doppler radar named the MU (Middle and Upper) Radar, which can detect vertical profiles of Doppler spectrum that composed of bothrain drop itself and air movements.

The rainfall intensity on the ground is usually not equivalent to the rainfall intensity estimated from the conventional radar. To improve the accuracy of the radar-estimated rainfall, we observe and analyze the vertical profile of the rain drop size distribution (DSD), then create a new formulation of the vertical profile of DSD. Based on the obtained information, first, a new formulation of DSD which considers rainfall type, rainfall intensity and observed DSD from the Disdrometer is developed. Then, the analysis of the vertical profile of DSD in the selected rainfall type is carried out to investigate the possibility of determing relationships among parameters for the DSD.

The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite is being developed by JAXA and NICT. This paper describes mission objectives, technical performance, resource allocation, critical design, proto-flight test (PFT) of the DPR instrument and satellite system test status. The DPR system PFT has completed in February 2012. DPR has handed over to NASA and integration of the DPR to the GPM core spacecraft have completed in May 2012. GPM core spacecraft satellite system test has started at NASA Goddard Space Flight Center. After completion of all satellite system tests, the GPM core spacecraft will be sent to JAXA Tanegashima Space Center and launched by H-IIA launch vehicle.

A dual Ka-band radar system is developed by the Japan Aerospace Exploration Agency (JAXA) for the GPM DPR algorithm development. The dual Ka-radar system which consists of two identical Ka-band radars can measure both the specific attenuation and the equivalent radar reflectivity at Ka-band. Those parameters are important particularly for snow measurement. Using the dual Ka-radar system along with other instruments, such as a polarimetric precipitation radar, a windprofiler radar, ground-based rain measurement systems, the uncertainties of the parameters in the DPR algorithm can be reduced. The verification of improvement of rain retrieval with the DPR algorithm is also included as an objective. Observations using the dual Ka-radar system were performed in Okinawa Island, in Tsukuba, over the slope of Mt. Fuji, and in Nagaoka, Japan. In Okinawa Island, the performance of the measurement has been confirmed by rain observation. In Tsukuba, one radar was directed in vertical and the other was in slant direction. By this configuration, total attenuation in the melting layer was estimated. The objective of the Mt. Fuji experiment was to observe the melting layer. In Nagaoka, a lot of wet snow fell, and much data on the snow have been obtained. The main results are measured k-Ze relationships. For the rain, reasonable k-Ze relationship has been obtained. The feasibility of total attenuation in melting layer has been studied. Different k-Ze relationships have been obtained in snow observations.

The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core observatory is developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). GPM objective is to observe global precipitation more frequently and accurately. GPM contributes to climate and water cycle change studies, flood prediction and numerical weather forecast. GPM consists of GPM core observatory and constellation satellites carrying microwave radiometers (MWRs) and/or sounders (MWSs). The frequent measurement will be achieved by constellation satellites, and the accurate measurement will be achieved by DPR with high sensitivity and dual frequency capability. GPM core observatory is jointly developed by National Aeronautics and Space Administration (NASA) and JAXA. NASA is developing the satellite bus and GPM microwave radiometer (GMI), and JAXA is developing DPR. GPM algorithms for data processing are developed jointly. The DPR consists of Ku-band (13.6 GHz) radar suitable for heavy rainfall in the tropical region, and Ka-band (35.55 GHz) radar suitable for light rainfall in higher latitude region. Drop size distribution information will be derived which contributes to the improvement of rainfall estimate accuracy. DPR will also play a key role to improve rainfall estimation accuracy of constellation satellites. DPR proto-flight test at JAXA Tsukuba space center is finished and it is delivered to NASA for integration to the GPM observatory. In this paper, DPR PFT test result at Tsukuba space center, DPR status in the GPM observatory environmental test, and DPR on-orbit calibration plan will be presented.

The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core spacecraft 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 contractor for DPR is NEC TOSHIBA Space Systems, Ltd. The configuration of precipitation measurement using an 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 spacecraft is 65 degrees, and the flight altitude is about 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 (35.55 GHz) precipitation radar (KaPR). According to the different detectable dynamic ranges, The KaPR will detect snow and light rain, and the KuPR will detect heavy rain. In an effective dynamic range in both KuPR and KaPR, drop size distribution information and more accurate rainfall estimates will be provided by a dual-frequency algorithm. The proto-flight test for DPR have finished in February 2012 and DPR integration on GPM core spacecraft was successfully completed in May 2012. The status of proto-flight model of DPR will be presented.

The Cloud Profiling Radar (CPR) on EarthCARE satellite is the first spaceborne Doppler radar for cloud and precipitation. In order to calibrate Doppler velocity, the external calibration study using active radar calibrator (ARC) is needed. The ARC must have the function to measure amplitude and phase of signal for the calibration. In addition, measurement of antenna beam angle is needed because satellite velocity is contaminated to radial velocity of radar measurement. Then the feasibility experiment was performed using the transmitting signal from CPR of CloudSat. In this paper, the preliminary result is reported and the calibration performance is discussed.

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.

The Dual-frequency Precipitation Radar (DPR) installed on the Global Precipitation Measurement (GPM) core satellite is being developed by JAXA and NICT. This paper describes objectives, technical performance, resource allocation, preliminary design, development model test, critical design and proto-flight test (PFT) of the DPR instrument. The DPR system PFT will be completed in 2011. After completion of all PFT, the DPR instrument will be verified as a space borne radar.

A dual Ka-band radar system is developed by the Japan Aerospace Exploration Agency (JAXA) for the Global Precipitation Measurement (GPM) dual-wavelength radar (DPR) algorithm development. The usage of the system is to measure backscattering and extinction cross sections by precipitation separately, and to provide testbed data for DPR algorithm. The parameters required in the DPR algorithm are raindrop size distribution for the liquid precipitation, and particle density, shape, and melting ratio for the solid precipitation. When the two Ka-radar systems separated by 10-20 km observe precipitation in between two radars, the specific attenuation can be measured. Along with other radar, a C-band radar, Mie scattering effect which is deviation from Rayleigh scattering could be estimated. A field experiment using the dual Ka-radar system is conducted in Okinawa Island. A C-band polarization Doppler radar is also operated, and preliminary result is presented.

National Institute of Information and Communication Technology (NICT, formally CRI) has developed a new C-band (5340 MHz) multi-parameter Doppler radar system with a bistatic Doppler radar network to establish the next-generation technology of rain observation for meteorological and hydrological applications such as weather forecasts and run-off analysis in predicting floods. This new radar is named COBRA (CRI Okinawa Bistatic polarimetric RAdar). The weather targets of this system are typhoons, Baiu-frontal rainfall, meso-scale precipitation in subtropical zones, and clear air turbulence. Two transmitter (klystron) units are used for the polarization observation. The transmission polarization for each pulse is selected from six possible polarizations. Additionally, NICT has developed equipment for weather radar that modulates the transmitting signal and demodulates the received signal (i.e., a pulse compression function). This equipment has been added to the existing COBRA system, forming a new system referred to as COBRA+. The COBRA+ system uses two traveling-wave tube amplifier (TWTA) transmitter units.

Communications Research Laboratory (CRL) has developed a new C-band (5340-MHz) multi-parameter Doppler radar system with a bistatic Doppler radar network. The purpose is to establish the next-generation technology of precipitation observation for meteorological and hydrological applications, such as weather forecasting and run-off analysis for predicting floods. This new radar is named COBRA (CRL Okinawa Bistatic polarimetric RAdar). The weather targets of the system are typhoons, Baiu-frontal rainfall, meso-scale precipitation in subtropical zones, and clear-air turbulence. Two transmitter (klystron) units are used for to observe the polarization characteristics of precipitation particles. The transmission polarization for each pulse is selected from six possible polarizations. The return signal is measured simultaneously by two receivers, one for the horizontal polarization and the other for the vertical polarization.

Sigmoid volvulus has often been treated by operative procedures. More recently, however, there has been an increasing number of case reports in which nonoperative reposition has been successfully conducted through the use of an endoscope, especially the colon fiberscope. In this report we present one case of sigmoid volvulus in which nonoperative reposition was achieved using a colon fiberscope. In Japan, to our knowledge, nine studies have so far described endoscopic reposition for this disturbance, including 21 cases in all. This paper presents a discussion of some of those cases for which a detailed description is available together with our case. Compared to four patients who received emergency operation for this disturbance in our clinic, there was no difference with regard to age or duration of affliction; however, the leucocyte count at the time of presentation tended to be higher in the operated group. In addition to evidence of intestinal necrosis and peritoneal irritation, this seems to suggest that evidence of inflammatory signs such as an increased leucocyte count may be helpful in deciding whether to apply nonoperative reposition.