What is an ISAR image?

Inverse synthetic-aperture radar (ISAR) is a radar technique using radar imaging to generate a two-dimensional high resolution image of a target. It is analogous to conventional SAR, except that ISAR technology uses the movement of the target rather than the emitter to create the synthetic aperture.

What is ISAR used for?

ISAR is used in military applications for identifying and targeting objects by their movement. The US Navy uses ISAR in aircraft like the Boeing P-8A to track ships and submarines. Like conventional synthetic aperture radar, ISAR systems are also used in space-based research to track moving objects.

What is the difference between SAR and ISAR?

In SAR, the synthetic aperture is obtained by the motion of radar antenna. For inverse synthetic aperture radar (ISAR), the radar is stationary, and the aperture is synthesized by the motion of the object. A basic type of ISAR is the synthetic aperture with rotating objects.

What is InSAR technology?

InSAR (Interferometric Synthetic Aperture Radar) is a technique for mapping ground deformation using radar images of the Earth’s surface that are collected from orbiting satellites. Unlike visible or infrared light, radar waves penetrate most weather clouds and are equally effective in darkness.

How is an ISAR image produced on a radar?

ISAR images are often produced by rotating the target and processing the resultant Doppler histories of the scattering centers. If the target rotates in azimuth at a constant rate through a ‘small’ angle, scatterers will approach or recede from the radar at a rate depending only on the cross range position-…

What are the disadvantages of the ISAR image?

Disadvantages of ISAR The ISAR imaging cannot obtain the real azimuth of the target. There sometimes exists a reverse image. For example, the image formed of a boat when it rolls forwards and backwards in the ocean. The ISAR image is the 2-D projection image of the target on the Range-Doppler plane which is perpendicular to the rotating axis.

Why does the Isar represent a planar surface?

The 2D ISAR representation of a target region is a planar surface. Integrated sidelobe return:ISAR image quality is degraded by rangeand azimuth compressionside lobes. The sidelobes are due to data truncationand can be reduced by the application of appropriate window functions. The sidelobes can cause significant image degradation.

How is Isar used in the maritime industry?

ISAR is used in maritime surveillance for the classification of ships and other objects. In these applications the motion of the object due to wave action often plays a greater role than object rotation.