Algorithmic Study of Reticle Based IR Seeker Simulators
Infrared target tracking devices (called IR seeker) are important part of the heat seeking missiles. They are based on a simply principle that heat produced by the operation of each machine emits strong infrared radiation. Take an aircraft for an example, an exhaust of the combustion engines produce much heat. The IR radiation is then detected and processed by the IR seeker which then guides the missile to the desired target.
There are many kinds of IR seeker. In this thesis we focus on ¡§reticle¡¨ and ¡§image¡¨ types of IR seekers. In the early 1950s, the IR technology is limited to a single detector. To be able to locate the target, a rotating reticle was placed before the detector. The pattern on the reticle introduces a specific modulation onto the output signals of the IR seeker thus giving the missile the equivalent of an IR eye. This is the built-in feature of the familiar sidewinder heat seeking missiles. In recent years, technology has greatly improved. The so called ¡§image¡¨ IR seeker uses a focal plane arrays (FPA), similar to the charge coupled device (CCD) of digital camera, to capture the IR image generated from the target. These high definition images are then processed by the computer and help the missile to track its targets.
We studied both types of IR seekers and developed approximation methods to generate IR signatures as well as algorithms to locate and identify the target. The ¡§image seeker¡¨ is technologically more advanced and can detect and track several targets simultaneously. Its inversion methods are however, simpler and easier to implement. From the simulation results, we can correctly locate of the target position. Due to the limited input information, more elaborate efforts are needed for the ¡§reticle seekers¡¨ because different reticle have different characteristics and need to be handled differently. To speed up the calculation, we use 2-D Fast Fourier transform of the reticle pattern and IR images of the target for both generation of detector waveforms and for target location. The overall results are satisfactory and meet the IR seeker simulator¡¦s requirements.
Advisor:Tzong-Lin Wu; Hung-Wen Chang; Nai-Hsiang Sun
School:National Sun Yat-Sen University
School Location:China - Taiwan
Source Type:Master's Thesis
Keywords:fft retical image ir seeker
Date of Publication:07/05/2005