This paper examines the physical mechanisms of reading out spatial-spectral absorption features in an inhomogeneously broadened medium using linear frequency-chirped electric fields. A Maxwell-Bloch model using numerical calculation for angled beams with arbitrary phase modulation is used to simulate the chirped field readout process. The simulation results indicate that any spatial-spectral ab...

All wearable centric location sensing technologies must address the issue of clock synchronisation between signal transmitting systems and signal receiving systems. GPS receivers, for example, compensate for synchronisation errors by incorporating a model of the receiver clock offset in the navigation solution. Drift between satellite clocks is also monitored to keep signal data in synch with G...

Digital watermarks for images can be made relatively robust to luminance and chrominance changes. More challenging problems are geometric or combined intensity/geometric attacks. In this work we use an additive watermarking model, commonly used in spread spectrum, using a new spreading function. The spreading function is a 2D circular chirp that can simultaneously resist JPG compression and ima...

We demonstrate a novel directly modulated transmitter, based on six-section photonic integrated circuit. The device uses unique master-slave configuration with variable optical attenuator in between, allowing decoupling of cavities and independent control the injection power. VOA also provides ability to find an optimum level that balances trade-off between extinction ratio chirp transmitted si...

Chirp radars are vulnerable to various types of deceptive jamming for example, smeared spectrum (SMSP) that generates multiple false targets, which lead and lag the true target. Unfortunately, radar system cannot distinguish target from ones because signal looks like echo. A new anti-jamming technique suppress targets identify easily is introduced. The proposed benefits fact SMSP has a differen...

This work proposes a unique technique for wideband chirp signals-based detection and estimate of the range, velocity, direction arrival (DOA) numerous far-field objects. A wide region is covered by signal that created. The targets reflect them, an echo radial as well DOA are extracted to identify Using LCT, determined. main goals system under consideration transmit band over area, detect nearby...

This paper presents a chirp based ultrasonic positioning system (UPS) using orthogonal chirp waveforms. In the proposed method, multiple transmitters can simultaneously transmit chirp signals, as a result, it can efficiently utilize the entire available frequency spectrum. The fundamental idea behind the proposed multiple access scheme is to utilize the oversampling methodology of orthogonal fr...

Females often adjust their mating preference to environmental and social conditions. This plasticity of preference can be adaptive for females and can have important consequences for the evolution of male traits. While predation and parasitism are widespread, their effects on female preferences have rarely been investigated. Females of the cricket Gryllus lineaticeps are parasitized by the para...