Estimate of sizes of small asteroids (cosmic bodies) by the method of stroboscopic radiolocation

Abstract

Radiolocation methods of probing minor celestial bodies (asteroids) by the nanosecond pulses can be used for monitoring of near-Earth space with the purpose of identification of hazardous cosmic objects able to impact the Earth.Development of the methods that allow to improve accuracy of determining the asteroids size (i.e. whether it measures tens or hundreds meters in diameter) is important for correctly estimating the degree of damage which they can cause (either regional or global catastrophes, respectively). In this paper we suggest a novel method of estimating the sizes of the passive cosmic objects using the radiolocation probing by ultra-high-resolution nanosecond signals to obtain radar signatures. The modulation envelope of the reflected signal, which is a radar portrait of the cosmic object, is subjected to time scale transformation to carrier Doppler frequency by means of radioimpulse strobing. The shift of a strobe within the probing period will be performed by radial motion of the object which will allow to forgo the special autoshift circuit used in the oscillographic technical equipment.The measured values of duration of radiolocation portrait can be used to estimate the mean radius of the object by using the average spatial length of the portrait. The method makes it possible to appraise the sizes of cosmic objects through their radiolocation portrait duration, with accuracy that is independent of the objects range.

Immunity of coherent stroboscopic processing system of ultra wideband signals during synchronous mode

“…Radio technical systems using signals of nanosecond duration have some advantages: a high resolution range can be reached, stealth, electromagnetic compatibility in conditions of working with narrow band radar systems in the same time etc. [1,2]. The probing signal of the radiolocation station is a periodic series of nanosecond duration microwave radio pulses and a processing this kind of signals usually is doing by using stroboscopic methods [3].…”

Scheme features of radio pulse gating for radar measurements

“…The time quantization inherent in these methods is well combined with the principle of digital filtering, which stimulates the use of stroboscopic methods in digital processing systems of broadband signals [2]. The combination of stroboscopic transformation with the numerical processing of information on computers significantly expands the field of application of these methods [3,4].…”

“…The necessary periodicity of the converted signal can be easily ensured in short-range detection systems. The linear mathematical model is widely used for theoretical analysis of the stroboscopic converter operation [1,3]. Such a model consists of a multiplier of the input and gate signals and a narrow-band filter BPF  , which selects one of the spectral components of the conversion results.…”