Rather than emitting pulses, passive radar systems rely on illuminators of opportunity, such as TV and FM radio, to illuminate potential targets. These systems are particularly attractive since they allow receivers to operate without emitting energy, rendering them covert. Many existing passive radar systems estimate the locations and velocities of targets. This paper focuses on adding an autom...

We introduce a new ambiguity function for general parameter estimation problems in curved exponential families. We focus the presentation on passive and active radar and sonar location mechanisms. The new definition is based on the Kullback directed divergence and reflects intrinsic properties of the model. It is independent of any specific algorithms used in the processing of the signals. For ...

The wireless measurement of various physical quantities from the analysis of the RADAR Cross Sections variability of passive electromagnetic sensors is presented. A millimetre-wave Frequency-Modulated Continuous-Wave RADAR is used for both remote sensing and wireless identification of sensors. Long reading ranges (up to some decameters) may be reached at the expense of poor measurement resoluti...

This research presents an ambiguity function analysis of the digital audio broadcast (DAB) waveform and one signal detection approach based on signal space projection techniques that effectively filters the direct-path signal from the receiver target channel. Currently, most Passive Coherent Location (PCL) research efforts are focused and based on frequency modulated (FM) radio broadcasts and a...

The Radar Remote Sensing Group in University of Cape Town has developed accurate modelling method that uses 3D maps of the Western Cape to predict the signal path loss between a transmitter, aircraft and a receiver in the Passive Coherent Location (PCL) system. The core objective of this thesis is to investigate the use of this modelling method to optimise the location of receivers in order to ...

The development of a new passive wireless pressure sensor, based on an electromagnetic transduction approach, is reported. The sensing element is a flexible high resistivity silicon membrane located above a coplanar quarter-wavelength resonator. The comprehensive coverage of the physical bases is beyond the scope of this paper. For the remote extraction of the applied pressure value, the passiv...

Passive microwave (PMW) measurements of ice-phase precipitation, such as snowfall and graupel, provide a physically direct basis for inferring the integrated amount of precipitation within a given field-of-view (FOV), assuming that other sources of noise can be adequately accounted for. However, the vertical distribution of precipitation within the FOV is generally unknown. By combining passive...

Many users of radar today are specifying a Low Probability of Intercept (LPI) as an important tactical requirement. The term LPI is that property of a radar that because of its low power, wide bandwidth, frequency variability, or other design attributes, makes it difficult to be detected by means of passive intercept receiver devices such as electronic support (ES), radar warning receivers (RWR...

Active and passive microwave measurements obtained by the dual-frequency Topex–Poseidon radar altimeter from the Northern Great Plains of the United States are used to develop a snow pack radar backscatter model. The model results are compared with daily time series of surface snow observations made by the U.S. National Weather Service. The model results show that Ku-band provides more accurate...