Unique system which is called as Antenna Direction Determination System (ADDS) toconfirm the real transmitting antenna direction of broadcasting satellite using TV signal strength data received at various ground stations at the same time has been developed. It is a method to be able to estimate even pointing error caused by sensor error, antenna reflector thermal distortion, etc. which can't be known by telemetry data. The principle of this method is applying the non-linear least square method against the signal strength level variation to get the movement of pre-measured antenna gain footprint. Practical antenna direction determination experiment was done using BSE launched in 1978 through its mission life. From the results of experiment in various operational condition, this system was verified for its capability and usefulness.
The theory of the dynamics of peripheral jet ACV is presented. The flow patterns under the bottom of ACV are classified into two types, i.e. underfed and overfed regimes. The mathematical models associated with such regimes are presented and the equations of those models are derived. The forced heaving oscillation of two-dimellsional ACV model is investigated experimentally-Variations of cushion pressure and lift force are measured and compared with the results obtained by the numerical calculation. The coincidence of these two results seems to be reasonable. The heavillg motion of ACV which is induced by the simple harmonic oscillation of the ground board is also analyzed numerically.
In general, probabilities of overlap which are key parameters in a collision risk model can be estimated from the frequency distribution of navigational errors. However, it is very difficult to determine the distribution of vertical navigational errors because the assigned altitude of aircraft is given by an isobaric surface (flight level) whose height depends on the atmospheric conditions. This paper describes a method of estimating the probability of vertical overlap of an aircraft pair without knowing the distribution function of vertical navigational errors directly. Using a pair of observed heights of aircraft (this is defined as the relative vertical distance), the probability of vertical overlap can be estimated from its frequency distribution empirically. Several cases of samplings and some results of a computer simulation carried out for an assumed error distribution in order to verify this method are discussed herein.
Relations between the physical properties in an iodine (I2) seeded argon free jet and its visualized image by a laser induced fluorescence (LIF) method using a multi-mode argon ion laser are described. It is shown that the flinge patterns of LIF in the jet result from the DOPPLER shifts of the rovibronic absorption lines of I2 due to the flow velocity component in the direction of the incident laser beam. It is also shown that the intensity of LIF depends strongly on the rotational temperature of I2.