For the non-intrusive

on-line and in-situ measurement of high-temperature combustion flame in engine

the method based on radiation spectroscopy (RS) was presented. The system using optical fiber spectrometer was designed for on-line parameters measurements of flame in engine. The wavelength response of charge-coupled device (CCD) was calibrated by the blackbody furnace. Then

the radiation spectroscopy range of 200-1100nm wavelength of high temperature flame in rocket based combined cycle (RBCC) engine ground testing was obtained by using this system

and the temperature and radiance of flame were determined with Planck radiation law and the least square method. It can provide important reference for combustion diagnostics and optimization of engine.