Alias Detection and Spectral Estimation Within Locally Stationary Random Fields

• Activity Number: 327
• Type: Topic Contributed
• Date/Time: Tuesday, July 31, 2012 : 10:30 AM to 12:20 PM
• Sponsor: Business and Economic Statistics Section
• Author(s): Idris Eckley*+ and Aimée Gott
• Companies: Lancaster University and Lancaster University
• Keywords: locally stationary processes ; aliasing ; random fields

Abstract

Aliasing occurs when power exists in an image at frequencies higher than the Nyquist rate (which is determined by the sampling rate). When it occurs, aliasing causes high frequency information to wrap round and mimic power at lower frequencies - as such it can have a deleterious effect on an analysis. For locally stationary random fields the situation can be a bit different in that aliasing can be intermittent, depending on whether the spectrum locally contains frequencies higher than the Nyquist rate or not. This talk will introduce recent work on the problem of alias detection and spectral correction within such two-dimensional processes.