We determined the precise three dimensional WGS84 Coordinates and the sea level height of Seoul Radio Astronomy Observatory (SRAO). In this study, we performed the simultaneous GPS observations at SRAO and Seoul GPS Reference Station(SGRS) of Korea Astronomy Observatory(KAO) for 3.5 hours from 17KST on October 27, 1999. We employed two different antennas, i.e., chokering antenna at SGRS of KAO and L1/L2 compact with groundplane antenna at SRAO. But we employed same type of receivers, i.e., Trimble 4000SSI at both observing places. The observed data were processed by GPSURVEY 2.30 software of Trimble with L1/L2 ION Free technique and broadcasting ephemeris of GPS Satellites because of very short baseline between SGRS of KAO and SRAO. We determined WGS84 latitude, longitude, height and the sea level height of SRAO with 37∘27′15.′6846N±0.′0004,126∘57′19.′0727E±0.′0002,204.89m±0.02m,181.38m±0.17m 37∘27′15.′6846N±0.′0004,126∘57′19.′0727E±0.′0002,204.89m±0.02m,181.38m±0.17m , respectively.

We have developed a Monte Carlo code, which solves the problem of radiative transfer in anisotropically scattering atmosphere. The radiative code is flexible in handlings of the system geometry, the distribution of scattering particles, and the source-particle geometry. This code treats the case of highly forward throwing scattering. As performance tests, we have compared the result of Monte Carlo calculations with that of Quasi-Diffusion method for a spherically symmetric cloud model.

We have built a near-infrared imaging camera with a PtSi array detector manufactured by the Mitsubishi Company. The PtSi detector is sensitive in the wavelength range 1 to 5μm 5μm . Quantum efficiency of PtSi is much lower than that of InSb and HgCdTe types. However, the PtSi array has advantages over the latter ones: (i)The read-out noise is very low; (ii)the characteristics of the array elements arc uniform and stable; (iii)it is not difficult to make a large PtSi array; and (iv) consequently the price is affordably low. The array used consists of 512×512 512×512 pixels and its size is 10.2mm×13.3mm 10.2mm×13.3mm . The filter wheel of the camera is equipped with J, H, K filters, and an aluminum plate for measuring the dark noise. The dewar is cooled with liquid nitrogen. We have adopted a method of installing the clock pattern and the observing softwares in the RAM, which Gill he easily used for other systems. We have developed a software with a pull-down menu for operating the camera and data acquisition. The camera has been tested by observing δ δ Orionis.

In order to check whether the 4-degree objective prism spectra can be used for deep spectroscopic studies of galactic structure, we measured the Rose(1984)'s seven indices between 3500 A and 4400 A for 19 Hyades stars on the Kiso Schmidt prism plate, K3496. By comparing the 4∘ 4∘ -indices with those of Rose(1984), we have found that Hδ/FeI Hδ/FeI , Hγ/4325 Hγ/4325 , and P(3912)/P(CN) measured on the 4-degree prism spectra, are still useful for the derivation physical parameters.

고수준의 천체화상처리에 관련된 모든 작업을 개인용 컴퓨터로도 충분히 수행할 수 있도록 제작된 화상처리용 그래픽라이브러리와 그 응용프로그램을 소개한다. 본 프로그램은 손쉽게 작업할 수 있는 대화식 한글 GUI 환경을 사용자에게 제공하여 다양하게 선택 가능한 작업메뉴로부터 천체화상처리를 비롯한 천문계산 및 도형출력등의 여러가지 응용프로그램을 실행시키도록 개발되었다. 그 주된 내용은 마우스에 의해 조작할 수 있는 통합처리환경의 제작. 양질의 천체화상 획득과 정밀측광을 위한 화상처리 그리고 출력장치에 구애받지 않는 화상출력의 구현이라 할 수 있다. 본 프로그램의 작성에는 C와 포트란언어가 사용되었으며 하드웨어에 관계없이 자유로운 한글처리를 위해 소프트웨어 자체에 한글을 내장하는 방법을 선택하였다.