Promising Methods and Tools of Radar Astronomy

We present the state of the art review for radar astronomy and its future prospects. We show that radar methods for probing asteroids can be used to monitor not only near-Earth space (distances of ∼ 106—107 km), but potentially also deep space with distances an order of magnitude greater. We consider a method for transforming the signal time scale that allows us to obtain a detailed radar portrait of an asteroid. We also provide an estimate of the maximum resolution of the asteroid’s rotation velocity using twisted radio signals in the case where rotation occurs in the plane of the image and the transverse Doppler effect is realized. The gain in measurement accuracy can be as much as ∼ 104 times. This gain in accuracy allows the selection of slowly rotating asteroids with rotation frequencies down to values of ∼ 2.2 day−1. Moreover, the use of twisted radio signals makes it possible to measure the angular velocity of an asteroid’s rotation in single-pulse location mode for minutes or tens of seconds without prolonged recording of its light curve.