Isao Kawano

LiteBIRD: a small satellite for the study of B-mode polarization and inflation from cosmic background radiation detection

LiteBIRD [Lite (Light) satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection] is a small satellite to map the polarization of the cosmic microwave background (CMB) radiation over the full sky at large angular scales with unprecedented precision. Cosmological inflation, which is the leading hypothesis to resolve the problems in the Big Bang theory, predicts that primordial gravitational waves were created during the inflationary era. Measurements of polarization of the CMB radiation are known as the best probe to detect the primordial gravitational waves. The LiteBIRD working group is authorized by the Japanese Steering Committee for Space Science (SCSS) and is supported by JAXA. It has more than 50 members from Japan, USA and Canada. The scientific objective of LiteBIRD is to test all the representative inflation models that satisfy single-field slow-roll conditions and lie in the large-field regime. To this end, the requirement on the precision of the tensor-to-scalar ratio, r, at LiteBIRD is equal to or less than 0.001. Our baseline design adopts an array of multi-chroic superconducting polarimeters that are read out with high multiplexing factors in the frequency domain for a compact focal plane. The required sensitivity of 1.8μKarcmin is achieved with 2000 TES bolometers at 100mK. The cryogenic system is based on the Stirling/JT technology developed for SPICA, and the continuous ADR system shares the design with future X-ray satellites.

LiteBIRD: mission overview and design tradeoffs

We present the mission design of LiteBIRD, a next generation satellite for the study of B-mode polarization and inflation from cosmic microwave background radiation (CMB) detection. The science goal of LiteBIRD is to measure the CMB polarization with the sensitivity of δr = 0:001, and this allows testing the major single-field slow-roll inflation models experimentally. The LiteBIRD instrumental design is purely driven to achieve this goal. At the earlier stage of the mission design, several key instrumental specifications, e.g. observing band, optical system, scan strategy, and orbit, need to be defined in order to process the rest of the detailed design. We have gone through the feasibility studies for these items in order to understand the tradeoffs between the requirements from the science goal and the compatibilities with a satellite bus system. We describe the overview of LiteBIRD and discuss the tradeoffs among the choices of scientific instrumental specifications and strategies. The first round of feasibility studies will be completed by the end of year 2014 to be ready for the mission definition review and the target launch date is in early 2020s.

Formation Flight Astronomical Survey Telescope (FFAST) mission in hard x-ray

A formation flight astronomical survey telescope (FFAST) is a new project that will cover a large sky area in hard X-ray. In particular, it will focus on the energy range up to 80keV. It consists of two small satellites that will go in a formation flight. One is an X-ray telescope satellite carrying a super mirror, and the other is a detector satellite carrying an SDCCD. Two satellites are put into a low earth orbit in keeping the separation of 12m. This will survey a large sky area at hard X-ray region to study the evolution of the universe.

Autonomous precision orbit control of ALOS-2 for repeat-pass SAR interferometry

ALOS-2, the next-generation Japanese SAR satellite, is designed to perform autonomous precise orbit control of Earth-referenced repeating orbits for effective repeat-pass SAR interferometry. The orbit control accuracy requirement of ALOS-2 is 500m (95%) with respect to the reference Earth-fixed flight path. This accuracy is guaranteed for all latitudes by not only drag-makeup maneuvers but also frequent inclination maneuvers. The on-board software of ALOS-2 can handle operations of orbit determination, maneuver prediction and planning, and maneuver executions for both drag-makeup maneuvers and inclination maneuvers. This feature of autonomy is expected to be great help for efficient ground operations of ALOS-2.

Hand motion capture for medical usage

The authors propose, not a non-contact devise which our research group has been developing, but a compact wearable device which allows for estimation of the hand pose (hand motion capture) of the subject. The devise has a miniature wireless RGB camera on the back side of users hand, rather than the palm side. Attachment of the small camera on the back side of the hand may make it possible to minimize the restraint on the subjects motions during motion capture. The conventional techniques attach the camera on the palm side of the hand for the reason that the images of fingertips always need to be captured by the camera before any other parts of the hand. In contrast, our image processing algorism, the authors propose here, is capable of estimating the hand pose with no need for capturing first the fingertips. Our system allows doing hand and finger motion capture without his psychological burden and physical constraints in clinical diagnosis.

FFAST mission to study the evolution of the universe in hard x-ray

A “formation flight astronomical survey telescope” (FFAST) is a new project that will cover a large sky area in hard X-ray. In particular, it will focus on the energy range up to 80 keV. It consists of two small satellites that will go in a formation flight. One is an X-ray telescope satellite carrying a “super mirror” and the other is a detector satellite carrying an SDCCD. Two satellites are put into a low earth orbit. They are in a formation flight with a separation of 20 m. Since two satellites are put into Keplerian orbit, the observation direction is moving the sky rather than pointing to a fixed direction. This project will survey a large sky area at hard X-ray region to study the evolution of the universe.

Development of a New Generation Spaceborne GPS Receiver

We are investigating a New Generation Spaceborne GPS Receiver that can determine a position more precisely, but which is smaller, with lower cost and lower power consumption than a conventional receiver. This new type of spaceborne receiver includes a CMOS Silicon on Insulator (SOI) chip and adopts a direct