“For Milliarcsecond or Better Accuracy”

Abstract

The accuracies being achieved in astrometry, celestial mechanics, Earth Orientation, ephemerides and time have been improving significantly in recent years.The introduction of the improved astronomical constants, ephemerides, time scales and nutation as adopted from 1976 to 1984 has had the desired effect of permitting the investigation of systematic effects at precisions of an order of magnitude better than previously possible.Therefore, there have been many developments in observational data, in theories, and in astronomical computations that have promised, or claimed, to deliver accuracies of a milliarcsecond or better.Working Groups had been established with interrelationships in their scopes of activities. It did not appear that any of the working groups were prepared to present final recommendations that would be generally accepted.