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| Spectrum Correction with a Triangular Window |
Zhang Qiang1,2,Zhang Pin3,Zhang Mingtong3
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| 1.Architecture Engineering School, Shanghai Normal University, Shanghai 201418, China;2.Insitute of Structure Engineering and Disaster Reduction, Tongji University, Shanghai 200092,China;3. College of Land Resources and Environment, JAU, Nanchang 330045, China |
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Abstract The spectrum correction is a promised approach to overcome the fence picket effect of the fast Fourier transforms (FFT); however the formula for the triangular window case is not available from references. Two approaches were proposed here to the triangular window case. The first one makes use of the first and second highest spectral lines, but needs iteration to solve a nonlinear equation numerically. The second one makes use of the second and third highest spectral lines that locate at two sides of the first highest spectral lines. The simulation examples show that, first; both approaches have much better performance than the conventional direct readings from the spectral lines. Second, the error can be ascribed to the interference from the negative frequency component.
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Received: 21 February 2008
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2009, Vol. 28 
