Imaging radar
Imaging radar provides its light to illuminate an area on the ground and take a picture at radio wavelengths.
The registered electromagnetic scattering is then mapped onto a two-dimensional plane, with points with a higher reflectivity getting assigned usually a brighter color, thus creating an image.
Imaging radar has been used to map the Earth, other planets, asteroids, other celestial objects and to categorize targets for military systems.
A typical radar technology includes emitting radio waves, receiving their reflection, and using this information to generate data.
[4][5] Time-Frequency Domain techniques are essential in imaging radar to analyze and process signals that vary in both time and frequency.
Time-Frequency Domain techniques provide insights into how signal characteristics (e.g., frequency) evolve over time, enabling better understanding and extraction of target information.
The handle M-sequence UWB radar with horn and circular antennas was used for data gathering and supporting the scanning method.
Usually the reflected pulse will be arranged in the order of return time from the targets, which corresponds to the range direction scanning.
In all information gathering modes, lasers that transmit in the eye-safe region are required as well as sensitive receivers at these wavelengths.
The returned laser energy must be mixed with a local oscillator in a heterodyne system to allow extraction of the Doppler shift.
To obtain fine azimuth resolution, a physically large antenna is needed to focus the transmitted and received energy into a sharp beam.
[12] Inverse synthetic aperture radar (ISAR) is another kind of SAR system which can produce high-resolution on two- and three-dimensional images.
An ISAR system consists of a stationary radar antenna and a target scene that is undergoing some motion.
Monopulse radar 3-D imaging can obtain the 3 views of 3-D objects by using any two of the three parameters obtained from the azimuth difference beam, elevation difference beam and range measurement, which means the views of front, top and side can be azimuth-elevation, azimuth-range and elevation-range, respectively.
The point at which the ellipsoids intersect – known as a hot spot - reveals the exact position of a target at any given moment.
Its versatility and reliability make 4D imaging radar ideal for smart home, automotive, retail, security, healthcare and many other environments.
