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In physical-layer security and cryptography we are concerned with the security of the transmitted data, while in low probability of intercept (LPI) communication with protecting the privacy of the end users. In our recent publications related to LPI communications and radars over free-space optical (FSO) links we proposed to hide the constant-amplitude modulated data, imposed on thermal source beam, in ambient solar radiation to protect the end users privacy and at the same time improve the reliability and security, while reducing the detectability of transmitted signal by the adversary Willie. In order to study both LPI and covert communication concepts we have developed an FSO communication testbed at the University of Arizona campus with a 1.5 km-long FSO link. Here we present results of our FSO experiments, where we conducted both LPI and covert communications at data rates ranging from 125 Mb/s to 10 Gb/s, wherein the information beam is kept completely hidden under the ambient solar radiations as random thermal noise. To improve the system reliability to atmospheric turbulence effects we make use of wavelength diversity method as a low-cost, easy to implement and far more practical alternative to conventional adaptive optics systems.
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Incoherent Light Sources-Based Low Probability of Detection and Covert Radars over Atmospheric Turbulence Channels
In this paper we are concerned with the low probability of detection (LPD) and covert radars employing optical incoherent sources. Key idea of our proposed LPD/covert radar concept is to hide the radar signal in solar radiation by employing the broadband (>30 nm) Erbium-doped fiber amplifier source, modulating such source output beam with a constant amplitude modulation format at high-speed, and detect the presence of the target by the cross-correlation method. To demonstrate the proposed concept we developed an outdoor free-space optical (FSO) testbed at the University of Arizona campus. To improve the tolerance to atmospheric turbulence effects the adaptive optics is used. We demonstrate that the LPD/covert radar concept over strong turbulent FSO channel is feasible in a desert environment.
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- Award ID(s):
- 2244365
- PAR ID:
- 10537375
- Publisher / Repository:
- IEEE
- Date Published:
- ISBN:
- 979-8-3503-4702-9
- Page Range / eLocation ID:
- 259 to 261
- Format(s):
- Medium: X
- Location:
- Nis, Serbia
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/TELSIKS57806.2023.10315967
