摘要
本文叙述了流星雨双站观测预备计算的原理,这些原理自1987年以来已在实践中应用。
The preparatory calculation serves to choose time intervals for observation of meteor showers and to orientate the fields of view of the two stations for their full coincidence at the meteor level. The principle of the calculation is as follows. 1. An imaginary station is put just halfway between the two Stations. Meteors with azimuth A+90° or A-90° seen form the imaginary station, where anA=(_1)·with E, N being unit vectors from the imaginary station to east and to north and_1, _2 being site vectors of the two stations, will be equally distant from the two stations and will be optimal for triangulation. 2. Time intervals for observation of ameteor shower will be chosen as intersections of the interval of darkness and the interval with the radiant high enough above borizon, for the imaginary station instead of the two stations. 3. For orientation of the fields of view we choose such a point at the meteor level, that is distant from the radiant for about 40° and seen from the imaginary station with azimuth A+90° or A-90° and with height angle no less than h_0, where sinh_0=sinh/(1-(D/H)~2sin^2h) with H being height of the meteor level, D distance between a station and the lmaginary station and h the lowest height angle needed for the centre of the field of view of the station. 4.The direction of the above chosen point seen from the first station may be taken as the direction of the centre of its field of view. The direction of the centre of the field of view of the second station should be the geometrical centre of four directions, which correspond to four points symmetrically situated at the rim of the field of view of the frist station. 5.The above-mentioned principle can easily be generalized to the case of three or more sations. The calculation based on the principle has been put in practice since 1987.
