Japanese Space Research Articles

An Evaluation of the ALOS PALSAR L-Band Backscatter—Above Ground Biomass Relationship Queensland, Australia: Impacts of Surface Moisture Condition and Vegetation Structure

Focusing on woody vegetation in Queensland, Australia, the study aimed to establish whether the relationship between Advanced Land Observing Satellite (ALOS) Phased Array L-band SAR (PALSAR) HH and HV backscattering coefficients and above ground biomass (AGB) was consistent within and between structural formations (forests, woodlands and open woodlands, including scrub). Across these formations, 2781 plot-based measurements (from 1139 sites) of tree diameters by species were collated, from which AGB was estimated using generic allometric equations. For Queensland, PALSAR fine beam dual (FBD) 50 m strip data for 2007 were provided through the Japanese Space Exploration Agency's (JAXA) Kyoto and Carbon (K&C) Initiative, with up to 3 acquisitions available for each Reference System for Planning (RSP) paths. When individual strips acquired over Queensland were combined, `banding' was evident within the resulting mosaics, with this attributed to enhanced L-band backscatter following rainfall events in some areas. Reference to Advanced Microwave Scanning Radiometer-EOS (AMSR-E) data indicated that strips with enhanced L-band backscatter corresponded to areas with increased effective vegetation water content (kg m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> ) and, to a lesser extent, soil moisture (g cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> ). Regardless of moisture conditions, L-band HV topographically normalized backscattering intensities backscatter (σ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> ) increased asymptotically with AGB, with the saturation level being greatest for forests and least for open woodlands. However, under conditions of relative maximum surface moisture, L-band HV and HH σ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> was enhanced by as much as 2.5 and 4.0 dB respectively, particularly for forests of lower AGB, with this resulting in an overall reduction in dynamic range. The saturation level also reduced at L-band HH for forests and woodlands but remained similar for open woodlands. Differences in the rate of increase in both L-band HH and HV σ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup> with AGB were observed between forests and the woodland categories (for both relatively wet and dry conditions) with these attributed, in part, to differences in the size class distribution and stem density between non-remnant (secondary) forests and remnant woodlands of lower AGB. The study concludes that PALSAR data acquired when surface moisture and rainfall are minimal allow better estimation of the AGB of woody vegetation and that retrieval algorithms ideally need to consider differences in surface moisture conditions and vegetation structure.

Japanese space agency confirms its probe brought back asteroid dust

Japanese space agency confirms its probe brought back asteroid dust

Sense of Place, Community, and Nature Management in Ogasawara, Japan: Investigating the Obeikei Narrative

Multidisciplinary place studies are reviewed in order to provide a theoretical foundation on which to examine the Obeikei narrative, especially those who lived through the US Navy era (1945–1968) and who are now struggling to find their footing within the local community. The Obeikei sense of place and community are explored in terms of “getting by” within the Japanese hegemonic space, and “let nature be” within the discourse of nature management. The US Navy era was found to have a strong impact on the individual and collective identities of the Obeikei, given the unrestricted ecological encounters it allowed and the sociocultural values that emerged and formed the basis of everyday life and sense of community at this time. An examination of the Obeikei narrative provides insight into their attitudes towards nature, and why they have been reluctant to participate in the ecotourism project under way at this location—currently vying for World Heritage listing.

Japanese space policy during the 1980s: A balance between autonomy and international cooperation

In the mid-1980s, Japan decided not only to invest in a totally domestic rocket, “H-II,” to acquire its independent access to space, but also to participate in the U.S. Space Station program to promote international space cooperation. Not until then did Japan try to achieve simultaneously both autonomy and international cooperation. This paper reexamines how Japan achieved a balance between autonomy and international cooperation in its space activities during the 1980s, from the perspective of Japan–U.S. diplomatic history. Against the background of the Japan–U.S. relations of those days, the similarities and differences between the two big space programs made it possible for Japan to decide them at the same time of the mid-1980s.

Optical Intersatellite Communication

This paper describes the achievements in optical intersatellite communication based on technology developments that started in Europe (European Space Agency) more than 30 years ago. In 2001, the world-first optical intersatellite communication link was established (between the SPOT-4 and Advanced Relay and TEchnology MIssion Satellite (ARTEMIS) satellites), proving that optical communication technologies can be reliably mastered in space. In 2006, the Japanese Space Agency (JAXA) demonstrated a bidirectional optical link between its Optical Inter-Orbit Communications Engineering Test Satellite and ARTEMIS, and in 2008, the German Space Agency (DLR) established an intersatellite link between the near-field infrared experiment and TerraSAR-X satellites already based on the second generation of laser communication technology.

Emerging space powers: the new space programs of Asia, the Middle East, and South America

This work introduces the important emerging space powers of the world. Brian Harvey describes the origins of the Japanese space program, from rocket designs based on WW II German U-boats to tiny solid fuel 'pencil' rockets, which led to the launch of the first Japanese satellite in 1970. The next two chapters relate how Japan expanded its space program, developing small satellites into astronomical observatories and sending missions to the Moon, Mars, comet Halley, and asteroids. Chapter 4 describes how India's Vikram Sarabhai developed a sounding rocket program in the 1960s. The following chapter describes the expansion of the Indian space program. Chapter 6 relates how the Indian space program is looking ahead to the success of the moon probe Chandrayan, due to launch in 2008, and its first manned launching in 2014. Chapters 7, 8, and 9 demonstrate how, in Iran, communications and remote sensing drive space technology. Chapter 10 outlines Brazil's road to space, begun in the mid-1960's with the launch of the Sonda sounding rockets. The following two chapters describe Brazil's satellites and space launch systems and plans for the future. Chapters 13 and 14 study Israel's space industry. The next chapters look at the burgeoning space programs of North and South Korea. The book ends by contrasting and comparing all the space programs and speculating how they may evolve in the future. An appendix lists all launches and launch attempts to date of the emerging space powers.

Ground Compatibility Tests for Gravity Measurement of SELENE: Accuracies of Two- and Four-Way Doppler and Range Measurements

The Japanese lunar mission Selenological and Engineering Explorer (SELENE) was launched in September 2007 and continued its mission until June 2009, when the main orbiter impacted with the surface of the Moon. SELENE consisted of three satellites: Main, Rstar, and Vstar. Rstar’s tasks were to forward up-link signals from the Usuada Deep Space Center (UDSC) to Main, and to down-link returning signals from Main to UDSC. We refer to this tracking sub-system as a four-way Doppler measurement. In contrast, conventional tracking systems between Rstar and UDSC as well as between Main and ground stations are referred to as two-way Doppler and range measurements. Using Main and Rstar, we successfully observed the gravity field over the farside of the Moon. Because four-way Doppler measurements via a relay sub-satellite were a fundamental experiment in space for Japanese space agencies, compatibility of radiometric instruments onboard Main and Rstar to UDSC were carefully examined at the UDSC using components manufactured for flight models. These tests not only proved the feasibility of the four-way Doppler measurements but also provided biases and variations of the four-way Doppler and two-way Doppler and range measurements that were later taken into account during the processing of tracking data and the analysis of the lunar global gravity field.

The Study on the Japanese Space Development Strategy ―Focusing on the rule for Peaceful use of Space―

The Study on the Japanese Space Development Strategy ―Focusing on the rule for Peaceful use of Space―

Manifesting Democracy

The entry of Western democracy into Asia represents one of the most significant dimensions of the East-West cultural dialectic. The transformative formal and intellectual influences of Western democratic concepts on Asian urbanity and identity formation therefore remain paramount to the discourse on Asian cities today. This document explores the search for democratic space in Japan—the first non-Western democracy in the world. By tracing the evolution and shifts of Japanese public space over the last six decades, it attempts both a re-reading of the Japanese city as a democratic construct, and of democracy itself as a culturally appropriated model.

Sub-Kelvin cooler configuration study for the Background Limited Infrared Submillimeter Spectrometer BLISS on SPICA

The Background Limited Infrared Submillimeter Spectrometer (BLISS) is an instrument proposed for the Japanese space borne telescope mission SPICA. The BLISS concept is a suite of grating spectrometers which combine to cover the 40–400 μm range at resolving power R ∼ 700 with detector sensitivity approaching the natural photon background limits. To achieve the high sensitivity, the BLISS detectors require cooling to 50 mK, well below the 1.7 K cold stage provided on the SPICA spacecraft. We present a thermal architecture for BLISS that includes a thermal intercept stage actively cooled to a temperature in between the 1.7 K cold tip and the detector stage at 50 mK. This architecture requires, essentially, two coolers; one to cool the intercept stage from 1.7 K and one to cool the detectors from the intercept stage temperature to 50 mK. We compared several configurations of flight-heritage coolers to cool the intercept and detector stages. Of the various configurations studied, a continuous adiabatic demagnetization refrigerator (ADR) for each stage has the highest maturity, lowest heat dump at 1.7 K and total mass comparable to other approaches. Other options, such as a Herschel 3 He sorption cooler-ADR hybrid and the recently demonstrated closed cycle version of the dilution cooler on Planck are also feasible for BLISS on SPICA.

Observing Mercury: from Galileo to the stereo camera on the BepiColombo mission

AbstractAfter having observed the planets from his house in Padova using his telescope, in January 1611 Galileo wrote to Giuliano de Medici that Venus is moving around the Sun as Mercury. Forty years ago, Giuseppe Colombo, professor of Celestial Mechanics in Padova, made a decisive step to clarify the rotational period of Mercury. Today, scientists and engineers of the Astronomical Observatory of Padova and of the University of Padova, reunited in the Center for Space Studies and Activities (CISAS) named after Giuseppe Colombo, are busy to realize a stereo camera (STC) that will be on board the European (ESA) and Japanese (JAXA) space mission BepiColombo, devoted to the observation and exploration of the innermost planet. This paper will describe the stereo camera, which is one of the channels of the SIMBIOSYS instrument, aiming to produce the global mapping of the surface with 3D images.

Marco Polo – A Mission to Return a Sample from a Near-Earth Object – Science Requirements and Operational Scenarios

Marco Polo is a mission to return a sample from a Near-Earth Object of primitive type (class C or D). It is foreseen as a collaborative effort between the Japanese Space Agency (JAXA) and the European Space Agency (ESA). Marco Polo is currently in a Phase-A study. This paper focuses on the scientific requirements provided to the industrial study consortia in Europe as well as the possible mission scenario at the target object in order to achieve the overall mission science objectives. The main scientific reasons for going to a Near-Earth Object are to understand the initial conditions and evolution history of the solar nebula, to understand how major events (e.g. agglomeration, heating) influence the history of planetesimals, whether primitive class objects contain presolar material, what the organics were in primitive materials, how organics could shed light on the origin of molecules necessary for life, and what the role of impacts by NEOs would be in the origin and evolution of life on Earth.

日本の宇宙開発最前線を語る(特別講演)

日本の宇宙開発最前線を語る(特別講演)

Pulpits as Lecterns: Discourses of Social Change within Tokyo's Protestant Churches, 1890–1917

Beginning in the 1890s, Protestant churches in Tokyo offered a new kind of social space that encouraged an open, verbal communication of ideas about a modern and improved Japan. Such churches differed dramatically from the majority of Japanese secular and religious gathering spaces that were directly influenced by their strong ties to state authority. At church, pastors and respected lay speakers told listeners to individually imagine the nation and their appropriate places within it. Speaking and listening with the men were many educated, socially minded women who had just been barred from various forms of public life. These men and women used the church space to imagine and realize alternative versions of a new Japan. To analyze the discursive distinctiveness of Tokyo's Protestant churches, this paper examines laymen's speeches made before the Women's Group of Tokyo's most socially active church, Hongō, sermons in Tokyo's two largest Kumiai (Congregationalist) churches, Hongō and Reinanzaka, and the accounts of attendees influenced by both.

Research and development of the New Generation Sea Surface Temperature for Open Ccean (NGSST-O) product and its demonstration operation

Real-time generation and distribution of the New Generation Sea Surface Temperature for Open Ocean (NGSST-O) product began in September 2003 as a demonstration operation of the Global Ocean Data Assimilation Experiment (GODAE) High-Resolution Sea Surface Temperature Pilot Project. Satellite sea surface temperature (SST) observations from infrared radiometers (AVHRR, MODIS) and a microwave radiometer (AMSR-E) are objectively merged to generate the NGSST-O product, which is a quality-controlled, cloud-free, high-spatial-resolution (0.05° gridded), wide-coverage (13–63° N, 116–166° E), daily SST digital map. The NGSST-O demonstration operation system has been developed in cooperation with the Japanese Space Agency (JAXA) and has produced six years of continuous data without gaps. Comparison to in situ SSTs measured by drifting buoys indicates that the root mean-square error of NGSST-O has been kept at approximately 0.9°C.

A glance at spaces with closure-preserving local bases

Call a space X ( weakly) Japanese at a point x ∈ X if X has a closure-preserving local base (or quasi-base respectively) at the point x. The space X is ( weakly) Japanese if it is (weakly) Japanese at every x ∈ X . We prove, in particular, that any generalized ordered space is Japanese and that the property of being (weakly) Japanese is preserved by σ-products; besides, a dyadic compact space is weakly Japanese if and only if it is metrizable. It turns out that every scattered Corson compact space is Japanese while there exist even Eberlein compact spaces which are not weakly Japanese. We show that a continuous image of a compact first countable space can fail to be weakly Japanese so the (weak) Japanese property is not preserved by perfect maps. Another interesting property of Japanese spaces is their tightness-monolithity, i.e., in every weakly Japanese space X we have t ( A ¯ ) ⩽ | A | for any set A ⊂ X .

Space radiation environment effects on X-ray CCD background

Charge coupled devices (CCDs) are often employed as the detector of choice for observing X-rays in space. The instrument background experienced in orbit has a major impact on the overall sensitivity of the camera system. The instrument background for the European Space Agency X-ray Multi Mirror (XMM-Newton) mission was found to be much greater in orbit than that originally predicted pre-launch, the reasons for which still being up for discussion. The Geant4 toolkit provides a framework for Monte Carlo simulations in a variety of areas in science and is used here to simulate the instrument background for several CCD based detectors in-orbit in order to gain a further insight into the formation of the instrument background continuum. The missions discussed in this paper include the ESA XMM-Newton mission, the NASA Swift mission and the Japanese Space Agency Suzaku mission. These three missions allow a comparison between the effects of both the mission orbit and the detector construction on the instrument background count-rate. Analysis of the results from the simulation lead to the conclusion that knock-on electrons, produced when protons pass through the shielding, dominate the instrument background continuum at the XMM-Newton Highly Elliptical Orbit (HEO) with a perigee and apogee of approximately 7000 and 120 000 km respectively, forming an additional background component not considered in the pre-launch study. The surface properties of the detector and shielding have the greatest impact on the level of the instrument background due to the interaction length of the knock-on electrons produced. At the Low Earth Orbit (LEO) of Swift and Suzaku at approximately 600 km, the impact of the knock-on electrons is reduced due to the differing in-flux of protons, and the form of the instrument background can vary greatly with the detector construction. The inconsistencies between this study and the pre-launch simulations are discussed. Sensitivity considerations regarding the instrument background are deliberated with a view towards future missions.

Drumming Out a Message: Eisa and the Okinawan Diaspora (review)

Reviewed by: Drumming Out a Message: Eisa and the Okinawan Diaspora Ricardo D. Trimillos (bio) Drumming Out a Message: Eisa and the Okinawan Diaspora. Directed by Yoshitaka Terada. Osaka: National Museum of Ethnology, 2005. One DVD, 75:40 minutes. DVD/NTSC format. The DVD is a 75-minute documentary by the National Museum of Ethnology in Osaka. It considers 25 years of identity building by Okinawans in the Osaka region of Japan, a nation where Okinawans are regarded both as a domestic Other and as non-Japanese. Eisa is an Okinawan music-dance folk form that features drumming and song accompanied by sanshin lute in choreographed mass formations of 30–100 participants. The video is less about the performance form, and more about the role of performance in the formation of a diasporic identity. It documents day-long Eisa Festivals held by the Banyan Association in the Taisho Ward of Osaka, presumably in 2000 and 2002. It intercuts performance footage and interviews, principally with Okinawan voices and a few with Japanese ones. It clearly articulates an Okinawan/Japanese divide of ethnicity and culture, in contrast to a general external view of Okinawa as part of Japan, given its present political status. Okinawa was a kingdom widely involved with maritime trade throughout Asia from the 11th century onward. It came under Japanese control in 1609, losing its sovereign status. During the 1946–1972 interregnum, U.S. occupation forces controlled the islands. In 1972, Okinawa was returned to Japan, becoming its southernmost prefecture. This commentary is colored by three personal factors: my experiences with and advocacy for Okinawan performance, culture, and identity in Hawai’i; the argument that Okinawan traditional culture is at least as much Southeast Asian as it is East Asian; and my personal view that the Ryukyus have strong historical and cultural links to the northern Philippines. Although the focus of this film is on the social tensions between Okinawans and Japanese, the issues and observations presented resonate with many minority/ majority dyads, including Hawaiian/haole (white), Maori/pakeha (white), and Irish/English. There is a kind of universality in the tropes which most diasporic groups in a nonwar context can relate to. In particular, the film identifies difficulties of Okinawans living in a Japanese space, especially those of the nisei second generation born in Japan. Loss of heritage language, erasure of homeland [End Page 161] culture, conflicts of mixed ethnicity, and issues of acceptance by the societies of heritage and of birth are major concerns. Drumming departs from most documentaries in that there is no disembodied hegemonic voice providing narration or analysis. Rather, the topic for each section is presented in print title, with content presented via interview excerpts with full English translation in subtitle. Thus, voices are exclusively those of participants, although the gaze of the non-Okinawan filmmaker inevitably manifests itself. The video has five sections: “In the Beginning,” “In the Eyes of the Japanese,” “The Second Generation,” “Yamatonchu (the Japanese),” and “Umui (Emotions and Desires).” Opening with a performance by the Banyan (Gaijimaru) Association ensemble, the background of Okinawan labor immigration and social clubs for workers in the 1950s is presented in subtitle. Although scattered throughout the Kansai (southern) region of Honshu Island, émigrés eventually coalesced around eisa performance, originally part of Okinawan O-Bon observance—a Buddhist veneration of departed spirits, usually performed in August. “In the Beginning” refers to the founding of the Banyan Association in 1975, motivated by concerns for workers’ rights and by nostalgia for a homeland identity. The video foregrounds founding member Toshinori Tamaki as speaker and as performer. Other members describe their connections with Okinawan-ness through eisa, seeing it as a means for presenting an Okinawan Self to the Japanese Other. Themes of marginalization and assimilation are not just about Okinawan culture in Japan, but also about integrating cultures of Okinawan “outliers” such as Yaeyama and Miyako islands into a diasporic, Osaka-constructed, pan-Okinawan unitary. Although not extensively problematized, members point out that eisa is not originally a Ryukyu-wide genre. Nevertheless, the Osaka project attempts representation of the entire archipelago within the rubric of the Eisa Festival. One musician states there was no eisa in...

AKARI: space infrared cooled telescope

AKARI, formerly known as ASTRO-F, is the second Japanese space mission to perform infrared astronomical observations. AKARI was launched on 21 February 2006 (UT) and brought into a sun-synchronous polar orbit at an altitude of 700 km by a JAXA M-V rocket. AKARI has a telescope with a primary-mirror aperture size of 685 mm together with two focal-plane instruments on board: the Infrared Camera (IRC), which covers the spectral range 2–26 μm and the Far-Infrared Surveyor (FIS), which operates in the range 50–180 μm. The telescope mirrors are made of sandwich-type silicon carbide, specially developed for AKARI. The focal-plane instruments and the telescope are cooled by a unique cryogenic system that kept the telescope at 6K for 550 days with 180 l super-fluid liquid Helium (LHe) with the help of mechanical coolers on board. Despite the small telescope size, the cold environment and the state-of-the-art detectors enable very sensitive observations at infrared wavelengths. To take advantage of the characteristics of the sun-synchronous polar orbit, AKARI performed an all-sky survey during the LHe holding period in four far-infrared bands with FIS and two mid-infrared bands with IRC, which surpasses the IRAS survey made in 1983 in sensitivity, spatial resolution, and spectral coverage. AKARI also made over 5,000 pointing observations at given targets in the sky for approximately 10 min each, for deep imaging and spectroscopy from 2 to 180 μm during the LHe holding period. The LHe ran out on 26 August 2007, since which date the telescope and instrument are still kept around 40K by the mechanical cooler on board, and near-infrared imaging and spectroscopic observations with IRC are now being continued in pointing mode.

A study for the method of the Japanese social space constitution and its solution -From the viewpoint of the Aikido-

A study for the method of the Japanese social space constitution and its solution -From the viewpoint of the Aikido-