We present what to our knowledge are the first filtered Rayleigh scatt
ering temperature measurements and use them in sooting flame. This new
technique for the two-dimensional thermography in gas combustion over
comes some of the major disadvantages of the standard Rayleigh techniq
ue. It suppresses scattered background light from walls or windows and
permits detection of two-dimensional Rayleigh intensity distributions
of the gas phase in the presence of small particles by spectral filte
ring of tie scattered light. (C) 1996 Optical Society of America