Holographic Subsurface Radar Technology and Applications

Sparsely Sampled Wideband Radar Holographic Imaging for Detection of Concealed Objects

“…The latter circumstance was observed experimentally. To avoid "blind" depths, it was proposed to use wideband multifrequency signals which guaranteed high contrast of the displayed object for at least one of the operating frequencies [18]. An ultra-wideband (UWB) X-Band holographic system was developed in which the holographic data were processed by an on-site computer using a backpropagation algorithm based on the Fast Fourier transform technique to form the high resolution three-dimensional radar images of vehicles [19].…”

“…3. Essentially the same process is used in the X-band holographic radar systems discussed in [18] and [20]. However, as seen in Fig.…”

RASCAN holographic radar for detecting and characterizing dinosaur tracks

“…Rascan produces a real-time image (with one raster per scan line) on the display of a PC running the software Multiscan by RSLab [7]. Since Rascan produces 10 simultaneous images (two receiver polarizations at each of five discrete signal frequencies [1]), an algorithm developed in Matlab was used to calculate a single display image. This processing separately removes a constant background level from each image, then combines the 10 matching pixels (from each separate image) as a sum of squares [8].…”

“…Because of attenuation of offnadir reflections, only the central Fresnel rings are retained, and the interference pattern closely mimics the actual shape of the reflector [1]. Rascan radars have an effective scanning depth of up to 30 cm in dry sand and rock at 2 GHz, and 20 cm at 4 GHz [1], and are preferred for this work over traditional impulse subsurface radars because of superior spatial resolution at shallow depths and the smaller , lighter scanning transducer. This paper describes a new application in development by the Rascan Group: the detection and imaging of dinosaur tracks.…”

“…INTRODUCTION Holographic subsurface radar of the RASCAN type was initially developed for landmine detection and non-destructive testing of construction details of buildings, historic architecture and artworks [1] [2]. This type of radar provides very high resolution (approximately ¼ λ), completely non-destructive, but exclusively shallow subsurface imaging.…”