Modified radon-Fourier transform for reflective tomography laser radar imaging

Abstract

This paper presents imaging result of computer simulation using a modified Radon-Fourier transform algorithm to reconstruct images from reflective tomography data. Since the signal returned is reflected off the illuminated outer surface of an opaque target, only information about the exterior of the target can be obtained, and the images reconstructed using reflective tomography techniques is an outline view of the target cross section. The projection ( , ) p r φ and ( , )p r φ + o contain different information about the target surface, and will lead different Fourier estimates along the same line through the origin based on the standard Fourier-Slice tomography theorem. Here, using the functional similarity between transmission tomography and reflective tomography, we add the collinear reflective projections to become corresponding transmissive projections before Fourier transform. Then the target can be reconstructed from the Fourier domain using the same operations in transmission tomography. The computer simulation result demonstrates the effectiveness of this modified algorithm to reconstruct image in reflective tomography using the diffuse reflection model (lamberts body). Future research will include the development of image reconstruction based on this modified algorithm for targets with much more complicated reflective characters.

Reflective Tomography Lidar Image Reconstruction for Long Distance Non-Cooperative Target

“…With the emergence and development of lidar, tomography algorithm is introduced, which improves the accuracy and efficiency of laser imaging technology. At present, the commonly used classical algorithms include iRadon transform [3], FBP [10][11][12][13], and ART [14]. However, the iRadon transform algorithm can only restore the image roughly, which is far from the ideal imaging result.…”

“…The results are shown in Figure 7. In Figure 7a, the iRadon [3,9] results are illustrated just to show the target contour according to the definition in Equation ( 1), as mentioned in Section 3.1. In Figure 7(a4), for sparse ART with OMP algorithm mentioned in Section 3.2.2, because of using discrete Fourier transform as a sparse basis, it cannot make good use of the gradient sparse features of laser image, leading to obvious deviation between the reconstructed contour and the original target.…”

“…On the basis of the improvement of the lidar experimental system, the theory of LRT was further developed, and many efforts have been made to complete the non-cooperative space target detection. Jin conducted reflection tomography lidar imaging by pulse detection to obtain the image of the conical object in the laboratory environment and experiment preliminarily on the LRT imaging with the incomplete view of the projection data [3][4][5]. Zhang determined the limiting conditions of the sampling interval and sampling angle for laser reflective tomography imaging in sensing targets with typical shapes [6,7].…”

“…Radon-Fourier [3,9] transform is the basic tomographic algorithm, but its accuracy is low, and the reconstructed image has obvious artifacts. Therefore, the FBP algorithm [10][11][12][13] has become the most commonly used algorithm for laser reflection tomography.…”