Proto-Flight Model of SAR for 100kg Class Small Satellite

This paper presents the proto-flight model results of X band synthetic aperture radar for small satellites including the RF power amplifier, high speed data storage/transmission system, and the ground SAR response test results. The specifications of SAR performance are single polarization SAR with 3m ground resolution for strip map mode. 1 m ground resolution can be achieved with sliding spot light mode under condition of limited value of NESZ at 600km altitude orbit. The data down link is high speed X band down link with 2-3 Gbps. In May, 2019, 2.5Gbps down link with 64APSK modulation in dual polarization channels was demonstrated by RAPIS-1 Satellite. We will launch the first demonstration SAR satellite in 2020 as collaboration with a private company

Development Status of Compact X-band Synthetic Aperture Radar Compatible with a100kg-class SAR Satellite and Its Future Plan

We have proposed a novel SAR system compatible with a 100kg-class small satellite. This SAR development is funded for four years (2016-2019) by Japanese government. At present we are developing engineering model (EM). This paper describes the EM test preliminary results and the future plan. The specifications of SAR observation are single polarization SAR with 1m ground resolution at minimum. A size of the satellite is 0.7m x 0.7m x 0.7m on a rocket. A size of the deployed antenna is 4.9m x 0.7m. Novel parallel-plate slotted array antennas made of honeycomb panel have been developed. Six outputs from GaN HEMT power amplifiers are combined in a waveguide resonator and 1 kW RF transmitting power is fed to the antenna trough non-contact choke flanges at deployable hinges (patented)

Engineering-Model Results of X-Band Synthetic Aperture Radar for Small Satellite and its Application to Constellation Mission

This paper presents the engineering model results of this X band synthetic aperture radar for small satellites and its application to constellation missions.The specifications of SAR performance are single polarization SAR with 1m ground resolution at 350 km altitude and with 3m ground resolution at 600km altitude orbit. A satellite is supposed to be 130kg in mass and the size is 0.7m x 0.8m x 0.9m on a rocket. A size of the deployed antenna is 4.9m x 0.7m. A chirped transmitting signal is amplified in a six GaN HEMT 200W amplifier modules to be combined in a waveguide resonator. The type of antenna system is deployable plane antenna due to its compact stow volume. Novel parallel plate slotted array antennas have been developed. We have performed compact range test, near-field measurement of an antenna wing with 2.8m x 0.7m size. The peak aperture efficiency is measured to be higher than 50%. We will launch the first demonstration satellite in late 2019. We finally will build a constellation of several tens SAR satellites with 1-3m resolution to realize from every day to every few hours revisit

Hepatitis B virus strains of subgenotype A2 with an identical sequence spreading rapidly from the capital region to all over Japan in patients with acute hepatitis B

ObjectiveTo examine recent trends of acute infection with hepatitis B virus (HBV) in Japan by nationwide surveillance and phylogenetic analyses.MethodsDuring 1991 through 2009, a sentinel surveillance was conducted in 28 national hospitals in a prospective cohort study. Genotypes of HBV were determined in 547 patients with acute hepatitis B. Nucleotide sequences in the preS1/S2/S gene of genotype A and B isolates were determined for phylogenetic analyses.ResultsHBV genotype A was detected in 137 (25% (accompanied by genotype G in one)) patients, B in 48 (9%), C in 359 (66%), and other genotypes in the remaining three (0.5%). HBV persisted in five with genotype A including the one accompanied by genotype G; another was co-infected with HIV type 1. The genotype was A in 4.8% of patients during 1991-1996, 29.3% during 1997-2002, and 50.0% during 2003-2008 in the capital region, as against 6.5%, 8.5% and 33.1%, respectively, in other regions. Of the 114 genotype A isolates, 13 (11.4%) were subgenotype A1, and 101 (88.6%) were A2, whereas of the 43 genotype B isolates, 10 (23.3%) were subgenotype B1, 28 (65.1%) were B2, two (4.7%) were B3, and three (7.0%) were B4. Sequences of 65 (64%) isolates of A2 were identical, as were three (23%) of A1, and five (18%) of B2, but none of the B1, B3 and B4 isolates shared a sequence.ConclusionsAcute infection with HBV of genotype A, subgenotype A2 in particular, appear to be increasing, mainly through sexual contact, and spreading from the capital region to other regions in Japan nationwide. Infection persisted in 4% of the patients with genotype A, and HBV strains with an identical sequence prevailed in subgenotype A2 infections. This study indicates the need for universal vaccination of young people to prevent increases in HBV infection in Japan

Lack of association between the CARD10 rs6000782 polymorphism and type 1 autoimmune hepatitis in a Japanese population

Background: Previous genome-wide association studies have evaluated the impact of common genetic variants and identified several non-HLA risk loci associated with autoimmune liver diseases. More recent genome-wide association studies and replication analyses reported an association between variants of the CARD10 polymorphism rs6000782 and risk of type 1 autoimmune hepatitis (AIH). In this case-control study, we genotyped 326 Japanese AIH patients and 214 control subjects. Results: Genomic DNA from 540 individuals of Japanese origin, including 326 patients with type-1 AIH and 214 healthy controls, was analyzed for two single nucleotide polymorphisms (SNPs) in the CARD10 gene. We selected CARD10 rs6000782 SNPs and genotyped these using PCR-RFLP method and direct sequencing. The Chi square test revealed that the rs6000782 variant alle (c) was not associated with the susceptibility for AIH in a Japanese population [p = 0.376, odds ratio (OR) 1.271, 95 % confidence interval (CI) 0.747-2.161] in an allele model. Our data also showed that CARD10 rs6000782 variants were not associated with AIH or with the clinical parameters of AIH. Conclusions: In this study we examined an association between rs6000782 SNPs in the CARD10 gene and type-1 AIH. Results showed no significant association of rs62000782 with type-1 AIH in a Japanese population. This study demonstrated no association between CARD10 rs6000782 variants and AIH in a Japanese population