antennas: brightness temperature question

hello,

as very well known the brightness temperature varies with elevation and frequency. there is a location dependence (urban, rural...) as well. I am looking for graphs, equations and other information in order to quantify the brightness temperature with respect to all relevant parameters. I am particularly interested in the frequency range 800 MHz to 2.5 GHz.

thank you.
greets

Kraus - Radioastronomy gives a published graphs. It's accurate and for years it has been the reference book. That graph has been mentioned and copied on Agilent AN57-1

Others (and newly) information sources exists, but I' shoul'd check if they are for free.

Hello,

You previously stated:
"Others (and newly) information sources exists, but I' shoul'd check if they are for free."

Are they for free?
Where to get/buy them?

Thanks.
Best regards.