The formula works assuming (1) no extinction from clouds or fog and (2) the air number density equals 2.54E+19 molecules/cm3. To correct for the latter assumption, see the closing post in the Forum discussion.
The formula works assuming (1) no extinction from clouds or fog and (2) the air number density equals 2.54E+19 molecules/cm3. To correct for the latter assumption, see the closing post in the Forum discussion.