## Determination of Orbits and Dispersion Ellipsoids of Asteroids Potentially Hazardous for the Earth

Protecting the Earth against Collisions with Asteroids and Comet Nuclei, In: A. M. Finkelstein, W. F. Huebner, V. A. Shor (Eds) Proceedings of the International Conference “Asteroid-Comet Hazard-2009”, StP: Nauka, 262–267 (2010)

**Keywords**:
Very Long Baseline Interferometry (VLBI), Near Earth Objects (NEOs), determination of asteroid orbits, the dispersion ellipsoids, potentially hazardous asteroids, observation errors, orbital parameters, method of the least modulus (the least modulus method), the least-squares method, linear connection of mean errors of orbit parameters with observation errors, the assumption of nonlinearity

### Abstract

The influence of the observation error distribution on the orbits of 22 asteroids potentially hazardous for the Earth has been studied. First, we computed the mean errors of orbit parameters on the assumption of the linear connection of them with observation errors and then we compared obtained estimates with those resulting from the assumption of the nonlinearity of this connection. Secondly, we correlate orbital parameters and their errors obtained by the method of the least modulus with those obtained by the least-squares method. The general conclusion is that the dispersion ellipsoids calculated on the assumption of nonlinearity are more plausible, and the orbits and estimates of their errors calculated by the least modulus method are more robust compared to those obtained by the least-squares method