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The “Advanced Land Observing Satellite-3” (ALOS-3, nicknamed “DAICHI-3”) is the next high-resolution optical mission as a successor of the optical mission by the Advanced Land Observing Satellite (ALOS, “DAICHI”) in Japan Aerospace Exploration Agency (JAXA), and will be launched in Japanese Fiscal Year 2020. ALOS-3 is now under developing the flight model. The major missions of ALOS-3 are (1) to contribute safe and secure social including provision for natural disasters, and (2) to create and update geospatial information in land and coastal areas. To achieve the missions, the “WIde-Swath and High-resolution optical imager” (WISH, as a tentative name) is mounted on ALOS-3, which consists of the high-resolution panchromatic- and multispectral-bands.This paper introduces the overview of ALOS-3’s mission and the calibration and validation plan at JAXA. The standard product is the system corrected data using the sensor models, which will be provided from the sensor development team. Therefore, the sensor calibration is directly affected to the accuracies of the standard product. In addition, the sensor model based the Rational Polynomial Coefficient will be contained with level 1B2 standard product that can be used to process an ortho rectification and three-dimensional measurement from ALOS-3 images. As the target accuracy of WISH’s standard products, the geometric accuracies are less than 5 m in horizontal without ground control point (GCP), and 1.25 m in horizontal and 2.5 m in vertical with GCPs (1 sigma), and the radiometric accuracy is ± 10 % as absolutely and ± 5 % as relatively for multispectral band.

The "Advanced Optical Satellite" (nicknamed "ALOS-3") is the next high-resolution optical mission as a successor of the Advanced Land Observing Satellite (ALOS) in Japan Aerospace Exploration Agency (JAXA), and now conducting the Critical Design Review (CDR) phase. The mission objecttives of ALOS-3 are (1) to contribute safe and secure social including provisions for natural disasters, and (2) to create and update geo-spatial information. The "wide-swath and high-resolution optical imager" is designed to be achieved the missions, which consists of the panchromatic band with 0.8 m ground sampling distance (GSD) and multi-spectral six bands with 3.2 m GSD, and the observation swath width is 70 km at nadir. In this study, mission overview, and planned- and expected-products of ALOS-3 are introduced.

JAXA has continued to develop the Advanced Optical Satellite (called “ALOS-3”) since FY 2016, as a successor of the optical mission of the Advanced Land Observing Satellite (ALOS) “DAICHI” (2006-2011). The wide-swath and highresolution optical imager (WISH) is a main sensor of ALOS-3. It has capabilities to collect high-resolution (0.8m Pan / 3.2m MS at nadir) and wide-swath (70 km) images with a high geo-location accuracy to meet the mission objectives of ALOS-3. WISH has a Pan band and 6 MS bands. The MS equips the basic four bands (R, G, B and NIR) and 2 additional bands of "coastal" and "RedEdge" expected to use for the various applications. The development of WISH is in the final stage of the critical design phase. We have finished the test of engineering model of the primary mirror assembly with no critical problem. In addition, the mechanical environmental tests using the structure model was completed, and the demonstration for high accuracy assembling of the large off-axis telescope is undergoing. For the detector system, the evaluation of the engineering model of the CCDs was completed in early phase, and assembly of the flight CCDs has been started in advance. In the current schedule, PFM manufacturing and subsequent proto-flight tests would be conducted within about a year and WISH would be delivered to the satellite system by the middle of FY 2019. ALOS-3 equipped with WISH would be launched by H-IIA rocket in FY 2020.

The “Advanced Optical Satellite” (nicknamed “ALOS-3”) is the next high-resolution optical mission as a successor of the Advanced Land Observing Satellite (ALOS) in Japan Aerospace Exploration Agency (JAXA), and now conducting the Critical Design Review (CDR) phase. The mission objecttives of ALOS-3 are (1) to contribute safe and secure social including provisions for natural disasters, and (2) to create and update geo-spatial information. The “wide-swath and high-resolution optical imager” is designed to be achieved the missions, which consists of the panchromatic band with 0.8 m ground sampling distance (GSD) and multi-spectral six bands with 3.2 m GSD, and the observation swath width is 70 km at nadir. In addition, the satellite has the body pointing capability within 60 deg. from nadir that will contribute to an emergency observation. In this study, the simulated images generation is introduced to investigate the feasibility of the missions as a part of pre- flight phase study.

Accepted: 2005-10-31, 資料番号: SA1000411000

The Infrared Camera (IRC) is one of two focal-plane instruments on the AKARI satellite. It is designed for wide-field deep imaging and low-resolution spectroscopy in the near- to mid-infrared (1.8-26.5 micron) in the pointed observation mode of AKARI. The IRC is also operated in the survey mode to make an All-Sky Survey at 9 and 18 microns. The IRC is composed of three channels. The NIR channel (1.8-5.5 micron) employs a 512x412 InSb photodiode array, whereas both the MIR-S (4.6-13.4 micron) and MIR-L (12.6-26.5 micron) channels use 256x256 Si:As impurity band conduction (IBC) arrays. Each of the three channels has a field-ofview of approximately 10x10 arcmin., and they are operated simultaneously. The NIR and MIR-S channels share the same field-of-view by virtue of a beam splitter. The MIR-L observes the sky about 25 arcmin. away from the NIR/MIR-S field-of-view. The in-flight performance of the IRC has been confirmed to be in agreement with the pre-flight expectation. More than 4000 pointed observations dedicated for the IRC are successfully completed, and more than 90% of the sky are covered by the all-sky survey before the exhaustion of the Akari's cryogen. The focal-plane instruments are currently cooled by the mechanical cooler and only the NIR channel is still working properly. Brief introduction, in-flight performance and scientific highlights from the IRC cool mission, together with the result of performance test in the warm mission, are presented.

Infrared Camera (IRC) onboard AKARI satellite has carried out more than 4000 pointed observations during the phases 1 and 2, a significant amount of which were performed in the spectroscopic mode. In this paper, we investigate the properties of the spectroscopic data taken with MIR-S channel and propose a new data reduction procedure for slit-less spectroscopy of sources embedded in complicated diffuse background structures. The relative strengths of the 0th to 1st order light as well as the efficiency profiles of the 2nd order light are examined for various objects taken with MIR-S dispersers. The boundary shapes of the aperture mask are determined by using the spectroscopic data of uniform zodiacal emission. Based on these results, if the appropriate template spectra of zodiacal light emission and the diffuse background emission are prepared and the geometries of the diffuse structures are obtained by the imaging data, we can reproduce the slit-less spectroscopic patterns made by a uniform zodiacal emission and the diffuse background emission by a convolution of those template profiles. This technique enables us to obtain the spectra of infrared sources in highly complicated diffuse background and/or foreground structures, such as in the Galactic plane and in nearby galaxies.

AKARI is the first Japanese astronomical infrared satellite mission orbiting around the Earth in a sun-synchronous polar orbit at the altitude of 700 km. One of the major observation programs of the AKARI is an all-sky survey in the mid- to far-infrared spectral regions with 6 photometric bands. The mid-infrared part of the AKARI All-Sky Survey was carried out with the Infrared Camera (IRC) at the 9 and 18 µm bands with the sensitivity of about 50 and 120 mJy (5σ per scan), respectively. The spatial resolution is about 9.4" at both bands. AKARI mid-infrared (MIR) all-sky survey substantially improves the MIR dataset of the IRAS survey of two decades ago and provides a significant database for studies of various fields of astronomy ranging from star-formation and debris disk systems to cosmology. This paper describes the current status of the data reduction and the characteristics of the AKARI MIR all-sky survey data.

SPICA (Space Infrared Telescope for Cosmology and Astrophysics) is a Japanese astronomical infrared satellite project with a 3.5-m telescope. The target year for launch is 2017. The telescope is cooled down to 4.5 K in space by a combination of newly-developed mechanical coolers with an efficient radiative cooling system at the L2 point. The SPICA telescope has requirements for its total weight to be lighter than 700 kg and for the imaging performance to be diffraction-limited at 5 μm at 4.5 K. Material for the SPICA telescope mirrors is silicon carbide (SiC). Among various types of SiC, primary candidates comprise normally-sintered SiC, reaction-sintered SiC, and carbon-fiber-reinforced SiC; the latter two have been being developed in Japan. This paper reports the current design and status of the SPICA telescope along with our recent activities on the cryogenic optical testing of SiC and C/SiC composite mirrors, including the development of an innovative support mechanism for cryogenic mirrors, which are based on lessons learned from a SiC 70 cm telescope onboard the previous Japanese infrared astronomical mission AKARI.

The ASTRO-F is an on-going infrared satellite mission covering 2-200 μm infrared wavelengths. Not only the all-sky survey in the mid-IR and far-IR, but also deep pointing observations are planned especially at 2-26 μm. In this paper, we focus on the near-infrared (NIR) channel of the infrared camera (IRC) on board ASTRO-F, and describe its design, and results of the imaging mode performance evaluation as a single component. The NIR consists of 4 lenses (Silicon - Silicon - Germanium - Silicon) with a 412 * 512 In:Sb detector. Three broad-band filters, and two spectroscopic elements are installed covering 2-5 μm wavelengths. Since the ASTRO-F telescope and the focal plane are cooled to 6 K, the evaluation of adjustment of the focus and the end-to-end test of the whole NIR camera assembly have to be done at cryogenic temperature. As a result of measurements, we found that the transverse magnification and distortion are well matched with the specification value (1 versus 1.017 and 1 %), while the chromatic aberration, point spread function, and encircled energy are slightly degraded from the specification (300 μm from 88 μm, > 1pixel from ~ 1pixel, 80 % encircled energy radius > 1pixel from ~ 1pixel). However, with these three measured values, in-flight simulations show the same quality as specification without degradation. In addition to the image quality, we also verified the ghost image generated from the optical element (1 % energy fraction to the original image) and the slightly narrowed field of view (10' * 9.5' from 10' * 10'). For the responsivity, the NIR shows expected response. Totally, the NIR imaging mode shows satisfactory results for the expected in-flight performance.

The MIR-L is the mid-IR (12-26 μ m) instrument for Japanese infrared astronomical satellite, the ASTRO-F. The instrument has 2 observing modes: a wide field imaging mode with a field of view of 10.7 × 10.2 arcmin 2 and a low resolution spectroscopic mode with a spectral resolution R = λ/Δλ about 20. The spectroscopic mode provides with not only slit-spectroscopy for extended sources but also slitless-spectroscopy for point sources. We describe here the design, manufacturing, and performance evaluation of the cryogenic optical system of the MIR-L. The concept of the optical system design is to realize wide field observations with a compact size. The instrument employs a refractive optics of 5 lenses (CsI - CsI - KRS-5 - CsI - KRS-5) with a 256×256 pixel Si:As IBC array detector, 3 filters, and 2 grisms. The refractive indices of CsI and KRS-5 at the operating temperature of about 6 K have ambiguities because of the difficulty of the measurements. We therefore designed the MIR-L optics with tolerances for the uncertainties of the indices. Since both CsI and KRS-5 have the fragility and the large thermal expansion, we designed a specialized mounting architecture to prevent from making damages and/or decentrations of the lenses at cryogenic temperatures under the serious vibration during the launch. As a result, the optical system of the MIR-L has passed both vibration and thermal cycle tests without damage and performance degradation, and achieved diffraction limited performance over its full wavelength range at the operating temperature.

MIR-L is a 12-26μm channel of Infrared Camera(IRC) onboard ASTRO-F. The camera employs a refractive optics which consists of 5 lenses (CsI - CsI - KRS-5 - CsI - KRS-5) and a large format Si:As IBC array detector (256 x 256 pixels). The design concept is to realize a wide field of view with a compact size. It has 2 observing modes: a wide field imaging with a field of view of 10.7 x 10.2arcmin2 or a pixel resolution of 2.5 x 2.4arcsec2/pixel in 3 bands (12.5-18μm, 14-26μm, 22-26μm), and low resolution spectroscopy with a spectral resolution R = λ/Δλ ≈40 in 2 bands 11-19μm,18-26μm). It also has a small slit to adapt for spectroscopic observations of extended sources. We describe the current design of the optics and the mounting architecture of MIR-L and evaluation of the optical performance at cryogenic temperatures.

An all-sky survey in two mid-infrared bands which cover wavelengths of 5-12um and 12-26μm with a spatial resolution of ~9" is planned to be performed with the Infrared Camera (IRC) on board the ASTRO-F infrared astronomical satellite. The expected detection limits for point sources are few tens mJy. The all-sky survey will provide the data with sensitivities more than one order of magnitude deeper and with spatial resolutions an order of magnitude higher than the Infrared Astronomical Satellite (IRAS) survey. The IRC is optimally designed for deep imaging in pointing observations. It employs 256x256 Si:As IBC infrared focal plane arrays (FPA) for the two mid-infrared channels. In order to make observations with the IRC during the survey mode of the ASTRO-F, a new operation method for the arrays has been developed - the scan mode operation. In the scan mode, only 256 pixels in a single row aligned in the cross-scan direction on the array are used as the scan detector and sampled every 44ms. Special cares have been made to stabilize the temperature of the array in the scan mode, which enables to achieve a low readout noise compatible with the imaging mode (~30 e-). The flux calibration method in the scan mode observation is also investigated. The performance of scan mode observations has been examined in computer simulations as well as in laboratory simulations by using the flight model camera and moving artificial point sources. In this paper we present the scan mode operation method of the array, the results of laboratory performance tests, the results of the computer simulation, and the expected performance of the IRC all-sky survey observations.

The Infrared Camera (IRC) is one of the focal-plane instruments on board the Japanese infrared astronomical space mission ASTRO-F. It will make wide-field deep imaging and low-resolution spectroscopic observations over a wide spectral range in the near- to mid-infrared (2-26um) in the pointed observation mode of the ASTRO-F. The IRC will also be operated in the survey mode and make an all-sky survey at mid-infrared wavelengths. It comprises three channels. The NIR channel (2-5um) employs a 512x412 InSb array, whereas both the MIR-S (5-12um) and the MIR-L (12-26um) channels use 256x256 Si:As impurity band conduction (IBC) arrays. The three channels will be operated simultaneously. All the channels have 10'x10' fields of view with nearly diffraction-limited spatial resolutions. The NIR and MIR-S share the same field of view, while the MIR-L will observe the sky about 25' away from the NIR/MIR-S field of view. The IRC will give us deep insights into the formation and evolution of galaxies, the properties of brown dwarfs, the evolution of planetary disks, the process of star-formation, the properties of the interstellar medium under various physical environments, as well as the nature and evolution of solar system objects. This paper summarizes the latest laboratory measurements as well as the expected performance of the IRC.

The infrared camera(IRC) onboard ASTRO-F is designed for wide-field imaging and spectroscopic observations at near- and mid-infrared wavelengths. The IRC consists of three channels; NIR, MIR-S and MIR-L, each of which covers wavelengths of 2-5, 5-12 and 12-26 micron, respectively. All channels adopt compact refractive optical designs. Large format array detectors (InSb 512x412 and Si:As IBC 256x256) are employed. Each channel has 10x10 arcmin wide FOV with diffraction-limited angular resolution of the 67cm telescope of ASTRO-F at wavelengths over 5 micron. A 6-position filter wheel is placed at the aperture stop in each channel, and has three band-pass filters, two grisms/prisms and a mask for dark current measurements. The 5 sigma sensitivity of one pointed observation is estimated to be 2, 11 and 62 micro-Jy at 4, 9, 20 micron bands, respectively. Because ASTRO-F is a low-earth orbiting satellite, the observing duration of each pointing is limited to 500 seconds. In addition to pointed observations, we plan to perform mid-infrared scanning observation. Fabrications of the flight-model of NIR, MIR-S, and the warm electronics have been mostly completed, while that of MIR-L is underway. The performance evaluation of the IRC in the first end-to-end test (including the satellite system) is presented.

We report on the extensive tests to characterize the performance of the infrared detector arrays for the Infrared Camera (IRC) on board the next Japanese infrared astronomical satellite, ASTRO-F. The ASTRO-Fwill be launched early 2004 and the IRC is one of the focal plane instruments to make observations in 2-26μm. For the near-infrared observations of 2-5μm, a 512x412 InSb array will be employed, while two 256x256 Si:As arrays will be used for the observations of 5-26μum in the IRC. Both arrays are manufactured by Raytheon. To maximize the advantage of the cooled telescope and extremely low background radiation conditions in space, the dark current and readout noise must be minimized. The heat dissipation of the arrays also has to be minimized. To meet these requirements and achieve the best performance of the arrays, we optimized the array driving clocks, the bias voltage, and the supply currents, and evaluated the temperature dependence of the performance. In particular, we found that the voltage between the gate and source of the FET of the multiplexer SBRC-189 had a strong dependence on temperature. This effect becomes a dominant source for the noise unless the temperature is kept within 20mK. We have achieved the readout noises of about 30e- and 40e- with the correlated double sampling for the flight model readout circuits of the InSb and Si:As arrays, respectively. These noises ensure that the background-limited performance can be achieved for the observations of IRC in the 4-26μm range in the current observing scheme. In addition, we are now planning to make scan mode observations by IRC. We have developed a new operation way of the arrays to achieve the stable response and low readout noise in the scanning operation for the first time. The IRC is now installed in the flight model cryostat and the first end-to-end test has just been completed. We report on the expected performance of the IRC together with the array test results.

The design overview and current development status of the Infrared Camera (IRC) onboard the Japanese infrared space mission, ASTRO-F (commonly called as the Infrared Imaging Surveyor, IRIS), are presented. The IRC is one of the focal plane instruments of ASTRO-F and will make imaging and low- resolution spectroscopy observations in the wide spectral range of the near- to mid-infrared of 2 - 26 micrometers . ASTRO-F will be brought into an IRAS-type sun-synchronous polar orbit. The IRC will be operated in the pointing mode, in which the telescope will be pointed at a fixed target position on the sky for about 10 minutes. The pointed observation may be scheduled up to three times per orbit. The IRC has three channels: NIR (2 - 5 micrometers ), MIR-S (5 - 12 micrometers ) and MIR-L (12 - 26 micrometers ). All of the three channels use refractive optics. Each channel has a field-of-view of 10' X 10' with nearly diffraction-limited spatial resolution. The NIR and MIR-S channels simultaneously observe the same field on the sky, while the MIR-L observes the sky about 20' away from the NIR/MIR-S position. State- of-the-art large format array detectors manufactured by Raytheon/IRCoE are employed for the IRC. The NIR channel uses a 512 X 412 InSb array, and 256 X 256 Si:As IBC arrays are used for the MIR channels. Fabrication of the proto-model has been completed and the preliminary performance test is under way.

Basic design and current development status of IRC, infrared camera on-board the IRIS is presented. IRC employs state-of- the-art format IR arrays for imaging and low-resolution spectroscopy at wavelength 2-25 micrometers . IRC consists of 3 cameras; NIR, MIR-S, and MIR-L. These 3 channels simultaneously observe different fields of the sky, with diffraction-limited spatial resolution.