[in Japanese]

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A key technology for designing a compact mobile receiver for direct broadcasting satellites (DBS) is presented and three sub-antenna arrangements are shown. In-phase combiner circuits for the output of the sub-antennas increase the antenna gain while keeping the beamwidth equal to that of the sub-antennas. Phase locked loop (PLL) performance is analyzed in terms of both the lock range and capture range. The driving mechanism of the turntable in the azimuth is studied from the points of view of weight and cost. A compact DBS mobile receiver for small cars is fabricated taking into account the above studies. Experiments in Tokyo, Osaka, and Fukuoka verified that it can receive satellite signals with a C/N of more than 12 dB.

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Holograms have been produced using image data observed with a geostationary meteorological satellite (GMS), namely, the meteorological satellite Himawari. First, an image in the Northern Hemisphere is synthesized from two-frame GMS image data. Then, 100-frame image data, having 256 × 256 pixels, are calculated from the image by viewpoint transformation. In image recording, these sequential image data are exposed on a holographic film of about 7×20 cm² using a liquid-crystal television panel having 146×160 pixels as a spatial light modulator. The hologram synthesizing time is nearly 1 hr. In this way, a reconstructed image can be observed with laser light illumination. To eliminate flicker in the reconstructed image, the angle of the viowpoint transformation must be set at 0.55°/frame in generating the original 100-frame images.

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