Quote Originally Posted by Andre Germain View Post
Alex, it is never too late... to share information!

Indeed, foil or mirror look down would fix the issue but then you'd have to keep that mirror clean, from at least insects (with proper geometry in a shielded box, rain can be avoided). Wish you had suggested this before I began with the Phidget so many years ago

As for AmbT vs SkyT, can you post some data?


I put my excel spread sheet in the public area of my drop box: https://dl.dropboxusercontent.com/u/...ty%20Index.xls . Some things need to be explained. MB refers to my favorite peak, Mogollon Baldy (New Mexico) that I used as my principal measure of ground-level air clarity. On a clear day,to the naked eye, patches of snow, trees, and rock are visible (about 6mi away). I have a Davis weather station that I used for the local measurements of airT, humidity, etc. For the skyT, I have an IR kitchen thermometer that goes to something like -60F. (Now I have a Phidiget.)
If you move the graph, there are a couple of points hidden behind it that plot the line. The second page of the spreadsheet determines a point's style.
In general, the farther off the shown line one gets, the worse the observing conditions, as indicated by my comments in the spread sheet. (Unfortunately, I do not highlight the speadsheet entry when a point is clicked.) I suspect that maybe humidity, or something else, would help separate the points. The time over which the first set of observations was made, there was a massive forest fire to our east, the Silver Fire. It was a very extensive fire, and if the wind was from the East, did much to affect the sky conditions. (BTW, the measurements are taken at an altitude of 6700' just north of Silver City, NM).

Anyway, hope you find the data useful

Alex Woronow (alex_at_awkml_dot_com)