The fluorescent scattering of UV sunlight and self-absorption by the nitric oxide (NO) &ggr; bands between 2000--2500 ¿ are quantified for the purpose of inferring NO density profiles as a function of altitude in the mesosphere and above. Rotational line emission rate factors and cross sections are calculated at a variety of temperatures. The observed variation of the solar spectrum across the &ggr; bands and its effect on emission rate factors are explored by using irradiance measurements that resolve features down to 0.1 ¿. The model also includes quenching by O2 and N2, multiple scattering, temperature effects, attenuation of the solar irradiance by O2 and ozone, and self-absorption with the summation of adjacent rotational features. Results indicate that for resonant &ggr; bands, the rotational structure in emission is not symmetric to that in absorption so that as self-absorption increases the shape of the observed emission envelope changes. For &ggr;(1,0) this is largely characterized by an increase in the integrated emission observed longward of 2151 ¿ compared to shortward. It is found that solar irradiances measured at 0.1 ¿ resolution decrease the calculated &ggr;(1,0) and &ggr;(0,0) band emission rate factors by less than 3% compared to those measured at 2 ¿ resolution. However, more Fraunhofer structure included in the calculation is reflected in the relative intensities of the rotational features. It is also found that extinction of the solar irradiance by ozone and quenching by O2 rapidly reduce the &ggr;(1,0) emission rate factor with decreasing altitude below 60 km.