[CF-metadata] Reflectance channel satellite imagery units

From: Jonathan Gregory <j.m.gregory>
Date: Mon, 14 May 2012 15:25:47 +0100

Dear Mike

> We thought about using "1', but Paragraph 3.1 in CF 1.6 states "1" can be used for fractions or parts of a whole. Reflectance factor is neither a fraction nor part of a whole so I think the better option is Jim's suggestion - no units attribute, unless we're missing something about the uses of "1".

My understanding of the text:

The conforming unit for quantities that represent fractions, or parts of a
whole, is "1".

is that you can use it for dimensionless numbers. Reflectance is a fraction
in one sense: reflected/transmitted. I think that statement is there in order
to make clear that CF does *not* support inventing arbitrary dimensionless
units such as reflectance_factor, as it goes on to say in that para. I believe
the CF checker treats no unit and units of 1 as equivalent.

Best wishes

Jonathan
Received on Mon May 14 2012 - 08:25:47 BST