I am looking for help from all remotesensing experts to get the DN value.I have an equation to find out the DN value.For that i need to get
1.Light tansmittence in the air,
2.Downwelling irradiance above the sea surface within the given spectral band and time of year and the day when the image was collected.
3.Factor that accounts for the loss of irradiance at air-sea interface due to reflectance
4.Reflectance of bottom features
5.extinction coefficent for water
kindly help me to learn how to get these fro the satellite images or how to calculate?