In this paper, we discuss the effect that photon polarization has on the quantum radar cross section (QRCS) during the special case scenario of when the target is enveloped in either a uniform electric field or magnetic field and all of its atomic electric/magnetic dipole moments become aligned (target polarization). This target polarization causes the coupling between the photon and the matter to change and alter the scattering characteristics of the target. Most notably, it causes scattering to be very near zero at a specified angle. We also investigate the relationship between electric and magnetic types of coupling and find that the electric contribution dominates the QRCS response.
The effectiveness of various dynamic calibration targets emulating human respiration are analyzed. Potential advantages of these devices relate to easier calibration methods for human detection testing in through-wall and through-rubbles situations. The three devices examined possess spherical polyhedral geometries. Spherical characteristics were implemented due to the unique qualities spheres possess in regards to calibration purposes. The ability to use a device that is aspect independent is favorable during the calibration process. Rather than using a traditional, static calibration sphere, a dynamic, sphere-like device offers the ability to resemble breathing movements of the human body. This motion opens the door for numerous types of Doppler testing that is impossible in a static calibration device. Monostatic RCS simulations at 3 GHz are documented for each geometry. The results provide a visual way of representing the effectiveness of each design as a dynamic calibration target for human detection purposes.
It has been found that the quantum radar cross section (QRCS) equation can be written in terms of the Fourier transform of the surface atom distribution of the object. This paper uses this form to provide an analytical formulation of the quantum radar cross section by deriving closed form expressions for various geometries. These expressions are compared to the classical radar cross section (RCS) expressions and the quantum advantages are discerned from the differences in the equations. Multiphoton illumination is also briefly discussed.
Quantum radar is an emerging field that shows a lot of promise in providing significantly improved resolution compared to its classical radar counterpart. The key to this kind of resolution lies in the correlations created from the entanglement of the photons being used. Currently, the technology available only supports quantum radar implementation and validation in the optical regime, as opposed to the microwave regime, because microwave photons have very low energy compared to optical photons. Furthermore, there currently do not exist practical single photon detectors and generators in the microwave spectrum. Viable applications in the optical regime include deep sea target detection and high resolution detection in space. In this paper, we propose a conceptual architecture of a quantum radar which uses entangled optical photons based on Spontaneous Parametric Down Conversion (SPDC) methods. After the entangled photons are created and emerge from the crystal, the idler photon is detected very shortly thereafter. At the same time, the signal photon is sent out towards the target and upon its reflection will impinge on the detector of the radar. From these two measurements, correlation data processing is done to obtain the distance of the target away from the radar. Various simulations are then shown to display the resolution that is possible.
Quantum radar serves to drastically improve the resolution of current radar technology using quantum phenomena. This paper will first review some of the proposed ideas and engineering designs behind both entanglement radar and coherent state radar design schemes. Entanglement radar is based on first entangling two photons, then sending one of the entangled photons out towards the target, and keeping the other one at home. A correlation between the two photons is analyzed to obtain information. Coherent state quantum radar relies on using coherent state photons and a quantum detection scheme in order to beat the diffraction limit. Based on the above, a proposed design concept to implement of a coherent state quantum radar is presented for simultaneously determining target range and azimuth/elevation angles.