컴퓨터 시뮬레이션을 통해서 레이더 타겟들에 대한 레이더 유효면적(RCS)을 측정하고, 그들의 성능특성을 분석하였다. 또한, 상용레이더 리프렉터의 구조적 특징을 검토하였다. 그리고, 수동형 레이더 리프렉터의 최적 설계조건을 선택했다. 연구결과, X-band(λ=3.2cm에서 10λ 크기의 원형 평판으로 구성된 옥타헤데랄 형태의 레이더 리프렉터가 최적 성능을 나타냈다. 그러나, 새로 적용될 2000 SOLAS 규정을 수용하기 위해서는 X-band 와 S-band 모두에 적용하기 위해서 더 큰 크기의 원형평판이 필요하다.

Radar is an indispensible equipment in all vessels under way. In Korea there are many fishing net buoys near the coast, which causes an enormous threat to safe navigation because it is very difficult to detect the buoys by radar due to their small radar cross section. In this study RTE(Radar Target Enhancer) was installed on the fishing net buoy and its echo was analysed carefully. The results showed the possibility of wide detection of targets, especially small targets such as fishing net buoys, navigation buoys and etc.

The Radio Navigation System(R. N. S.) has been progressed consistantly with the development of electric-electronic engineering techniques since the R. D. E had been developed in 1910. The R. N. S. mostly depends on either Hyperbolic Navigation System(H. N. S.) or Spherical Navigation System(S. N. S.) in the ocean, and on Rectangular Navigation System (R. N. S.) in the air near the airport or an a combinations of the above systems in both area. Another effective R. N. S may be the Ellipse-Hyperbola Navigation System(E-H N. S.), which is proposed and named such in this paper. The equations calculating GDOP are derived and the GDOP values are calculated in the case of H. N. S., S. N. S, and E-H. N. S., respectively, for the specified case that four transmitting stations are arranged on the apex of a square, Then the GDOP diagrams of above navigation systems are presented for qualitative comparison in this paper. To measure the distances from the receiver to the stations in S. N. S., and/or the sum of distances to two stations in E-H N. S., the time synchronization between the transmitter clocks and the receiver clock is a major premise. The author has proposed the algorithm for getting this synchronmization utilizing the by S. N. S. or E-H N. S while GDOPs of those are relatively good. Even though clock synchronization error is a voidable due to the fix error used, the simulated results shows that the position accuracy of S. N. S. and E-H N. S. by the proposed method is far upgraded compared with that determined by H. N. S. directly, as far as the outer region of transmitter arrangement is concerned.

Nowadays Hyperbolic Navigation System-LORAN, DECCA, OMEGA, OMEGA-is available on the ocean, and Spherical Navigation System, GPS (Global Positioning System) is operated partially. Hyperbolic Navigation System has the blind area near the base line extention because divergence rate of hyperbola is infinite theoretically. The Position Accuracy is differ from the cross angle of LOP although each LOP has the same error of quantity. GDOP(Geometric Dilution of Precisoin) is used to estimate the position accuracy according to the cross angle of LOP and LOP error. Hyperbola and ellipse are crossed at right angle everywhere. Hyperbola and ellipse are used to LOP in Rectangular Navigation System. The equation calculating the GDOP of rectangular Navigation System is induced and GDOP diagram is completed in this paper. A scheme that can improve the position accuracy in the blind area of Hyperboic Navigation System using the Rectangular Navigation System is proposed through the computer simulation.

In this paper, the equations calculating GDOP are induced in Hyperboic, and Spherical Navigation System, respectively, The GDOP diagram shows that the DGOP in the inner region of Beacons is similar each other, but the GDOP of Hyperboic Navigation System is much larger than that of Spherical Navigation System due to GDOP in the outer region of Beacons. The authors propose the algorithm estimating the pulse starting time using the Hyperboic Navigation System, and prove that if Navigation use the Spherical Navigation System by adopting the proposed Algorithm -in this case, "Pseudo Sperical Navigation System" - in the outer region where GDOP is becoming large, the position errors can be reduced.e reduced.