Volumetric SAR near-field upsampling and basebanding

Highly sampled imagery offers many benefits to the radar practitioner, ranging from easier image coregistration to simple visual appeal. However, it is often overlooked due to the computational burden forming such an image imposes. Fast image formation typically imposes restrictions on the imaging scenario, for example synthetic aperture radar (SAR) far-field, and exploits parallelism through use of modern multi- core architecture. Imposing a SAR near-field requirement on the image formation limits the applicability of several of the faster algorithms, thus there is a need to create a general process to achieve highly sampled imagery, regardless of the imaging regime. In this letter, a method for accurately upsampling near-field (SAR) imagery is presented. This is applicable to both SAR near-field and SAR far-field scenarios. The methodology is discussed, and an example is provided in the form of a SAR near-field volumetric image of a miniature tank. The limitations to the approach are discussed and prospects for future work given.