The rapid progress in the focal plane technology enables us to use large format infrared sensors, such as 256 × 256 InSb/HgCdTe and 1040 × 1040 PtSi arrays. Infrared two-dimensional sensors make possible not only the imaging observations but a deep detection limit. The development of a large format infrared array is one of the most important breakthroughs in observational astronomy.

We propose to build a mosaic infrared camera for the SUBARU 8-m telescope. The SUBARU telescope is designed to reach a diffraction limited image at infrared wavelengths with a wide field of view (six arcsec at the Cassegrain focus). The camera is designed to cover the entire field of view with PtSi infrared sensors and to employ a weighted shift-and-add operation and a real-time image processing. The efficiency of the mosaic infrared camera and power of the 8-m telescope have a strong potential to meet challenging problems. Most of the regions of the near infrared sky are not covered with enough sensitivity. It is essential to conduct infrared deep and wide surveys.

We have observed the 12CO (Ishizuki et al 1990) and 13CO emission of the central 65″ region of the galaxy IC342 at the high resolutions of 2.4″ for 12CO and 5.1″×4.2″ for 13CO using the Nobeyama Millimeter Array. The integrated intensities of 12CO and 13CO emission are shown in Fig.1 and 2, respectively.

History of correlators for radio interferrometer is briefly reviewed. Advantages and disadvantages of various methods are discussed and the most appropriate ways are given for various interferrometers. Challenges to the next generation short-wavelength interferrometer are also discussed.

This paper proposes a “half-sample delay switching” to suppress aliasing ghosts caused by finite frequency sampling without the clumsiness of a sharp anti-aliasing filter.

In mm-wave spectroscopy, the acousto-optic spectrometer (AOS hereafter) compares favourably with conventional spectrometers such as filter-banks or autocorrelators. Although its frequency resolution is limited to 20 kHz and its instantaneous bandwidth is limited to several hundred MHz, it has 103 resolvable points. Because of the simplicity and stability of the AOS, it is not difficult to construct and maintain a system of 104 resolvable points by the parallel operation of spectrometers. At Tokyo Astronomical Observatory (TAO) a new AOS has been constructed which is equipped with two different types of TeO2 AO deflectors and provides high resolution (38 kHz) or wide band (220 MHz) spectra. It has 1728 frequency channels (figure 1). Another AOS has been built at Kisarazu Technical College (KTC) for a CO survey at 115 GHz. It has 256 frequency channels and a bandwidth of 230 MHz (figure 2).