In this paper we review the main issues that are relevant for the detection of Extensive Air Showers (EAS) from space. EAS are produced by the interaction of Ultra-High Energy Cosmic Particles (UHECP) with the atmosphere and can be observed from an orbiting telescope by detecting air fluorescence UV light. We define the requirements and provide the main formulas and plots needed to design and optimize a suitable telescope. We finally estimate its expected performances in ideal conditions.
We summarise some basic issues relevant to the optimisation and design of space-based experiments for the observation of the Extensive Air Showers produced by Ultra-High Energy Cosmic Particles interacting with the atmosphere. A number of basic relations is derived and discussed with a twofold goal: defining requirements for the experimental apparatus and estimating the exptected performance.
As of 2023, the Square Kilometre Array will constitute the worlds largest radio telescope, offering unprecedented capabilities for a diverse science programme in radio astronomy. At the same time, the SKA will be ideally suited to detect extensive air showers initiated by cosmic rays in the Earths atmosphere via their radio emission. With its very dense and uniform antenna spacing in a fiducial area of one km$^2$ and its large bandwidth of 50-350 MHz, the low-frequency part of the SKA will provide very precise measurements of individual cosmic ray air showers. These precision measurements will allow detailed studies of the mass composition of cosmic rays in the energy region of transition from a Galactic to an extragalactic origin. Also, the SKA will facilitate three-dimensional tomography of the electromagnetic cascades of air showers, allowing the study of particle interactions at energies beyond the reach of the LHC. Finally, studies of possible connections between air showers and lightning initiation can be taken to a new level with the SKA. We discuss the science potential of air shower detection with the SKA and report on the technical requirements and project status.
The SPHERE-2 balloon-borne detector designed for extensive air shower (EAS) observations using EAS optical Vavilov-Cherenkov radiation (``Cherenkov light), reflected from the snow-covered surface of Lake Baikal is described. We briefly discuss the concept behind the reflected Cherenkov light method, characterize the conditions at the experimental site and overview the construction of the tethered balloon used to lift the SPHERE-2 telescope above the surface. This paper is mainly dedicated to a detailed technical description of the detector, including its optical system, sensitive elements, electronics, and data acquisition system (DAQ). The results of some laboratory and field tests of the optical system are presented.
We report on the first direct measurement of the basic features of microwave radio emission from extensive air showers. Using a trigger provided by the KASCADE-Grande air shower array, the signals of the microwave antennas of the CROME (Cosmic-Ray Observation via Microwave Emission) experiment have been read out and searched for signatures of radio emission by high-energy air showers. Microwave signals have been detected for more than 30 showers with energies above $3times10^{16}$,eV. The observations presented in this Letter are consistent with a mainly forward-beamed, coherent and polarised emission process in the GHz frequency range. An isotropic, unpolarised radiation is disfavoured as the dominant emission model. The measurements show that microwave radiation offers a new means of studying air showers at very high energy.
Future detection of Extensive Air Showers (EAS) produced by Ultra High Energy Cosmic Particles (UHECP) by means of space based fluorescence telescopes will open a new window on the universe and allow cosmic ray and neutrino astronomy at a level that is virtually impossible for ground based detectors. In this paper we summarize the results obtained in the context of the EUSO project by means of a detailed Monte Carlo simulation of all the physical processes involved in the fluorescence technique, from the Extensive Air Shower development to the instrument response. Particular emphasis is given to modeling the light propagation in the atmosphere and the effect of clouds. Main results on energy threshold and resolution, direction resolution and Xmax determination are reported. Results are based on EUSO telescope design, but are also extended to larger and more sensitive detectors.