What is the essential difference between microwave imaging and photography and scanning imaging?

The difference lies in the different carriers. Microwave imaging and photography strike the return of electromagnetic waves on the fluorescent screen, forming an array from shallow to deep, so a substantial "screen" is its carrier. Scanning imaging is to send the color and contrast of the scanned object to the processor in digital form through light irradiation. The processor is calculated and reorganized in the processor, and the processor is its carrier.

Microwave imaging is an imaging method with microwave as the information carrier. The principle is that the measured object is irradiated by microwave, and then the shape or (complex) dielectric constant distribution of the object is reconstructed by the measured value of the scattering field outside the object. Because the dielectric constant is closely related to the water content of biological tissues, microwave imaging is very suitable for imaging biological tissues.

When the large discontinuity limits the efficiency of ultrasonic imaging and the low density of biological tissue limits the use of X-rays, microwave can play a unique role and obtain information that cannot be obtained by other imaging methods. Microwave imaging has the characteristics of safety, low cost and temperature imaging in theory.

Imaging is an inverse scattering problem, and the target feature information is extracted according to the scattered echo signal. Many well-known imaging technologies, such as X-ray, laser, sound wave, microwave, millimeter wave, etc., differ only in the interaction between the selected information carrier and the target, while microwave imaging relies on the interaction between electromagnetic waves and the target to mine and extract the target information from the scattered echo signal and reconstruct the target characteristics.