Hi all, I am looking for a formula for refraction. At http://www.sundialsoc.org.uk/glossary/equations/equations.htm ist says:
10. Sun’s refraction Ro=1/ (tan(a+7.31/(a+4.4))) Ro is the refraction in arcmins for a temperature of 10ºC and an atmospheric pressure of 1010 mb. For other conditions, a multiplying factor of 0.28P/T is required, where P is the pressure in mb and T is the temperature in kelvins ( = temp in ºC + 273). but obviously refraction does also change with the sun's altitude. Only for low altitudes there will be refraction. Do you have a simple formula or source for this by hand? Danke, Thomas --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
