An online emission spectral tomography system with digital signal processor

Abstract

Emission spectral tomography (EST) has been adopted to test the three-dimensional distribution parameters of fluid fields, such as burning gas, flame and plasma etc. In most cases, emission spectral data received by the video cameras are enormous so that the emission spectral tomography calculation is often time-consuming. Hence, accelerating calculation becomes the chief factor that one must consider for the practical application of EST. To solve the problem, a hardware implementation method was proposed in this paper, which adopted a digital signal processor (DSP) DM642 in an emission spectral tomography test system. The EST algorithm was fulfilled in the DSP, then calculation results were transmitted to the main computer via the user datagram protocol. Compared with purely VC++ software implementations, this new approach can decrease the calculation time significantly.

Thermal computed tomography for biological tissue reconstruction based on radiation balance

“…The steps of numerical simulation are (a) A test model T(x,y), which is taken as the temperature distribution in a reconstruction layer of an optical-thin biological object, is given (that is the test function) 4 …”

“…However, these ECTs require the examinee to take some reagents, which is not suitable for testing biological specimens. Emission spectral tomography (EST) [4], a passive CT technique that needs neither light sources nor reagent-taking, has been widely adopted to probe the 3-D distribution of parameters of thermal fluid fields such as burning gas, flame and plasma etc. Although EST is prior proposed for detecting high-temperature objects, it then can be promoted for getting the internal information of low-temperature samples such as biological tissues with the development of thermal infrared detectors used to collect emission data in a number of directions.…”

Fused Entropy Algorithm in Optical Computed Tomography

“…Optical computed tomography (OpCT) techniques such as interferometry tomography [1][2][3], light beam deflection tomography [4], emission spectral tomography [5][6][7], etc., are a branch of computed tomography (CT), which is mainly applied to optical testing of 3-D distributions of physical variables of a number of fluid fields [8][9][10]. Due to the limitations of the testing environments and devices, most OpCTs encounter limited-view problems [11][12][13], e.g., incomplete testing views and/or incomplete data at each view, which results in worse reconstruction precision and lower spatial resolution than that seen in medical CT. To solve this problem, many OpCT algorithms have been developed since Gordon et al first proposed an algebraic reconstruction technique (ART) algorithm in the 1970s [14].…”

Multi-directional 3D flame chemiluminescence tomography based on lens imaging

“…Based on the imaging system, FCT can be classified into the following categories: (a) custom-made lens and film based multi-directional setup [3]; (b) lens and CCD camera based multi-directional setup [4][5][6][7][8][9][10][11][12][13][14][15]; and (c) fiber and CCD-based multi-directional setup [16]. Of these classes, (b), the lens and CCD camera, offers the highest resolution and is the easiest to set up and operate, giving it the greatest potential for commercialization.…”

“…So far, most studies on FCT that use lenses and CCD cameras are based on the parallel projection model, in which the projection is regarded as the integration of a signal along the entire line of sight [7][8][9][10]. However, due to the lens, the signal collected by a camera does not result from the integration along the parallel rays, as is assumed by the parallel projection approach [17].…”