The UV spectrum and the absorption cross sections of carbonyl fluoride (COF2) have been measured in the wavelength range 200--230 nm at 296 K with a resolution of 0.03 nm by diode array spectroscopy. Preliminary results of the determination of the quantum yield of COF2 at 193 nm and 296 K are presented. The new absorption cross sections and the new estimate of the quantum yield were used to calculate photodissociation rate constants at solar zenith angles ranging from 0¿ to 86¿ as a function of height (0--55 km). ¿ American Geophysical Union 1992