Krishnaprasad, Perinkulam S.Kugarajah, TharmarajahDayawansa, Wijesuriya P.A methodology for the determination of wafer temperature in Molecular Beam Epitaxy via diffuse reflectance measurements is developed. Approximate physical principles are not used, instead, patterns in the data (reflectance versus wavelength) are exploited via wavelet decomposition and Principal Component Analysis.en-USsensingdata compressionimage processingfeature extractionsemiconductor processmonitoringIntelligent Control SystemsTechnical Report