topic Solar Analyst - Transmissivity Value in ArcGIS Spatial Analyst Questions https://community.esri.com/t5/arcgis-spatial-analyst-questions/solar-analyst-transmissivity-value/m-p/88773#M1242 <HTML><HEAD></HEAD><BODY><P>Hi there,</P><P></P><P>Just a question regarding the calculation of the 'transmissivity' value for use of the Solar Radiation tool. So far I have been using the direct beam radiation divided by the extraterrestrial radiation corrected for the solar zenith angle at the time, however all the values come out far too big.</P><P>Has anyone had success with a particular method of calculation or chosen a particular hour (for example, using the radiation at 12 due to the smallest zenith angle)?</P><P></P><P>Thank you in advance for any replies,</P><P></P><P>Jess</P></BODY></HTML> Wed, 30 Jul 2014 11:42:39 GMT JessCartwright 2014-07-30T11:42:39Z Solar Analyst - Transmissivity Value https://community.esri.com/t5/arcgis-spatial-analyst-questions/solar-analyst-transmissivity-value/m-p/88773#M1242 <HTML><HEAD></HEAD><BODY><P>Hi there,</P><P></P><P>Just a question regarding the calculation of the 'transmissivity' value for use of the Solar Radiation tool. So far I have been using the direct beam radiation divided by the extraterrestrial radiation corrected for the solar zenith angle at the time, however all the values come out far too big.</P><P>Has anyone had success with a particular method of calculation or chosen a particular hour (for example, using the radiation at 12 due to the smallest zenith angle)?</P><P></P><P>Thank you in advance for any replies,</P><P></P><P>Jess</P></BODY></HTML> Wed, 30 Jul 2014 11:42:39 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/solar-analyst-transmissivity-value/m-p/88773#M1242 JessCartwright 2014-07-30T11:42:39Z