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In particular, supposing that the emitting radiation is at a frequency f 0 =c/λ 0, where λ 0 is the wavelength of the laser beam, for a moving target (i.e., aerosol particle or molecule) with a relative line-of-sight velocity v, the backscattered light detected by the lidar receiver has a frequency shift equal to Δf=2v/c.
A typical UWB system might use a bandwidth of one-third to one-half of its center frequency. For example, some systems use a bandwidth of about 1 GHz centered around 3 GHz. The two most common methods to increase signal bandwidth used in UWB radar, including SAR, are very short pulses and high-bandwidth chirping.
Lidar (/ ˈ l aɪ d ɑːr /, also LIDAR, LiDAR or LADAR, an acronym of "light detection and ranging" [1] or "laser imaging, detection, and ranging" [2]) is a method for determining ranges by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver.
Speckle imaging and eye testing using speckle also use the speckle effect. Speckle is the chief limitation of coherent lidar and coherent imaging in optical heterodyne detection. In the case of near field speckles, the statistical properties depend on the light scattering distribution of a given sample.
Ground-penetrating radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. It is a non-intrusive method of surveying the sub-surface to investigate underground utilities such as concrete, asphalt, metals, pipes, cables or masonry. [1] This nondestructive method uses electromagnetic radiation in the microwave band ...
Interferometric synthetic aperture radar, abbreviated InSAR (or deprecated IfSAR), is a radar technique used in geodesy and remote sensing.This geodetic method uses two or more synthetic aperture radar (SAR) images to generate maps of surface deformation or digital elevation, using differences in the phase of the waves returning to the satellite [1] [2] [3] or aircraft.
Multispectral imaging measures light emission and is often used in detecting or tracking military targets. In 2003, researchers at the United States Army Research Laboratory and the Federal Laboratory Collaborative Technology Alliance reported a dual band multispectral imaging focal plane array (FPA).
Laser Doppler velocimetry is used in hemodynamics research as a technique to partially quantify blood flow in human tissues such as skin or the eye fundus. Within the clinical environment, the technology is often referred to as laser Doppler flowmetry; when images are made, it is referred to as laser Doppler imaging.