This paper derives general equations of position determination of a receiver which are based on analysis of the time-of-arrival of range measurement signals emitted from GPS satellites and of other related data measured or estimated. The least-squares method is used to integrate and process above data, and to determine the position and clock offset of the receiver. Analytical relations of DOPs (Dilutions of Precision) to the relative geometry of GPS satellites and the receiver are also derived by assuming the uniform deployment of GPS satellites. The results of the simulation study for satellite navigation performance under several cases of the operational environment are shown to evaluate the effectiveness of the satellite navigation algorithms based on the least-squares estimation proposed in this paper.
This paper deals with a new bending test method for advanced composites. Although a conventional three- or four-point bending test is convenient to obtain bending strength and modulus, it has several disadvantages especially for advanced composites. A newly proposed method is based on a bending by means of axial compression and this method overcomes the above disadvantages. A set of testing device was designed and machined and several kinds of composites were tested. In addition to the bending strength, the method to evaluate the bending modulus was also developed. It has been made clear that the new method is suitable especially for high performance composites such as T800/epoxy graphite composites.