Kavraiskii Method

a method for the combined determination of the geographic latitude φ of a place and the time correction u (or the longitude λ) by astronomical observation.

The method was worked out during 1924–36 by V. V. Kavraiskii for the high latitudes (from +60° to +80°). It is based on observing at least two pairs of stars at equal elevations; in other words, it is a generalization of the Tsinger and Pevtsov methods. The azimuths of the stars in the pair should differ by about 180°, and the difference between the average azimuths of the two pairs (half-sums of the azimuths of the stars of the pair) should be about 90°. During observation the moments when stars pass the horizontal lines of the grid in the sight tube of a general-purpose instrument or zenith telescope are noted by stopwatch, and readings for the end of the level tube bubble are recorded to keep track of small changes in elevation of the position of the tube. Observations of n pairs of stars produce n equations, which are solved by the method of least squares and give φ and u.