The catalogue of the heliocentric orbits of 817 meteors recorded within the double station program of the video observation of meteors ar the Ondřejov observatory in years 1998-2001 is presented. The electronic version of the catalogue is available on http://www.asu.cas.cz/-meteor/catalogues. and Součástí článku jsou tabulky na str. 4-32.
In this work the method used up to now tor a positional reductions of the photographs is compared with other reductional formulas. It was found that the reduction formula presently used for determination of the zenith distance is suitable, however the formula for determination of the azimuth can be replaced by a new expression, which essentially improves the total positional reduction.