Performance evaluation of active sub-Terahertz systems in Degraded Visual Environments (DVE)

Abstract

This paper addresses the problem of critical operations in Degraded Visual Environment (DVE). DVE usually refer when the perception of a pilot is degraded by environmental factors, including the presence of obscurants from bad weather (e.g. fog, rain, snow) or accidental events (e.g. brownout, whiteout, smoke). Critical operations in DVE are a growing field of research as it is a cause of numerous fatal accidents for operational forces. Due to the lack of efficient sources and sensors in the Terahertz (THz) region, this domain has remained an unexplored part of the electromagnetic spectrum. Recently, the potential use of sub-Terahertz waves has been proposed to see through dense clouds of obscurants (e.g. sand, smoke) in DVE conditions. In order to conduct a performance evaluation of sub-Terahertz systems, several sub-terahertz systems (e.g. bolometer-array cameras, liquid helium cooled bolometers) were operated in artificial controlled DVE conditions at ONERA facilities. The purpose of this paper is to report field experiments results in controlled DVE conditions: attenuation measurements from 400 GHz to 700 GHz with a performance evaluation of different sub-Terahertz systems are presented.

Earth and Martian Sand and Dust Storms: A Comprehensive Review of Attenuation Modelling and Measurements

“…Solutions involving subterahertz (sub-THz) active imaging systems are proposed to investigate wavelengths sufficient for penetrating brownout conditions. Interested readers can refer to references [161][203] [194].…”

Modeling of an active terahertz imaging system in brownout conditions

“…In a 3-m-long wind tunnel [15], losses smaller than 0.4 dB have been observed between 94 and 217 GHz with a sand density ranging between 170 mg∕m 3 and 3379 mg∕m 3 . More recently, at higher frequencies (between 446 and 631 GHz), attenuations ranging between 1 and 3 dB have been reported in a 15-m-long tunnel [16].…”