Standardising units and formats (and ref frames?) in transmission

[Rob Seaman]

It's a good sign that we're wrestling with these sorts of issues  
(again).

Roy wrote:

> I agree with Alberto that restricting the diversity of units is a  
> very effective strategy, easier and perhaps more effective than  
> building complex infrastructure to handle that diversity.
>
> Proposal: As a first step, perhaps we could agree to have "No  
> Sexagesimal Inside"?
>
> Note: While users will see sexagesimal in the VO, it should always  
> be created at the final, presentation stage, along with the choice  
> of font sizes and colors. While users will be able to input  
> sexagesimal in the search boxes, it should always be converted by  
> the browser to decimal before going to the server.

Whether or not this is the right design choice, the question is  
whether this obviates the need for VO infrastructure complex enough to  
handle the breadth of astronomical usage.  Rather, doesn't this just  
relocate from the server to the client where a library to standardize  
units and formats is linked into the code?

These discussions keep coming up.  Perhaps a dispassionate analysis of  
VO use cases would reveal a requirement for such a library of  
astronomically aware software tools.  Astronomy is full of units and  
formats - astronomers aren't being quixotic when they choose diverse  
representations for overtly similar quantities:

	- http://www.amazon.com/Astrophysical-Quantities-Arthur-Cox/dp/0387987460
	- http://www.amazon.com/Astrophysical-Formulae-Radiation-Processes-Astrophysics/dp/3540296921/ref=pd_bxgy_b_text_b/190-9360854-9222241
	- http://aa.usno.navy.mil/publications/docs/exp_supp.php
	- http://www.amazon.com/Astronomical-Algorithms-Jean-Meeus/dp/0943396352
	...

Such a work product seems like it could be very popular with users  
independent of the VO functionality it would enable.

Rob