[ESP] asking for feedback on LAS

[Bryan Lawrence]

Hi Steve

Sorry about the slow reply; in part because I wanted to get some feedback 
locally, and in part because I hoped Andrew Woolf would get a chance for a 
chat with you during the opendap meeting ...

> At the December ESP meeting in Boulder I said I would follow
> up with a request for feedback on LAS: what needs to be
> added or modified in order to fill the needs that you see in
> the ESP portal design.   Our next LAS design meeting will be
> in early April so feedback in the next couple of weeks would
> be very timely

Anyway I think for us the key issues for LAS are web-services, modularisation, 
security, and graceful support for java-challenged browsers. I know that most 
of these are things you are thinking about (or actually doing) anyway, so I 
suspect there will be no surprises here.

In slightly more detail, from my perspective the modularisation and 
web-service issues are nearly the same, in so far as it would be nice to 
break up the components into browse, visualise, deliver, with independent 
web-services with well-defined (simple) interfaces. OK, so that's probably a 
little unfair as I know that you have got a large degree of modularisation 
but I understand that it's not as clean as it could be (you understand that I 
haven't done any of this myself, so feel free to shoot me as the messenger if 
I'm getting it wrong). (And apologies if this sounds carping, it's very 
obvious that a lot of work has gone into making it as good as it is now, not 
only in what it can do, but in terms of the existing modularisation).

I have heard that you are planning on making it possible to put IDL in the 
backend, this would be a good thing (TM), and hopefully the process of doing 
that might make the back-end visualisation separation even cleaner.

The security issue is still important to us; currently we use cookies to do 
this, but it's clumsy ... if you do go down the web-service route, then a 
certificate-based approach would be very helpful for us ... (although the 
sand isn't very firm underfoot for doing this as far as I can tell).

Our last issue is java related. We have a number of folk who are mac based and 
have in the past grumbled, it might be that things are better now (it seems 
that time may solve this and you may not have to do anything). However, a 
clean failure mode is important. I haven't tested this myself, it maybe that 
there is one at V6 and later?

Well, I had hoped to provide you with more info. We may do that over the next 
six months as we do have an internal project to try and use LAS V6+ (&CDAT) 
as one interface to most of our numerical model data, but it rumbles on as we 
have relatively little staff effort for that.

Why web-services and modularisation? In the slightly longer term, clearly we 
want to be able to have metadata services which return a URI which points to 
a LAS enabled service for a single dataset. (I think this is really the only 
way to avoid the existing browsing interface which is a very big problem for 
large systems). This might require the ability to dynamically generate a LAS 
service and populate the metadata backend with templated visualisation 
information and dynamic data information. If this were possible then it would 
be possible for different organisations to deal with their own metadata 
idiosnycracies and browsing concepts without imposing the LAS standard. 
We could also offer a wider variety of delivery mechanisms.

Oh, and while I'm on pie-in-the-sky, OGC Web-Mapping Server compatability?

OK, enough. Thanks for the opportunity to comment, and thanks also for a great 
piece of software as it is. People will always want more from a good thing! 

Bryan
-- 
Bryan Lawrence, Head NCAS/British Atmospheric Data Centre
web: www.badc.nerc.ac.uk  phone: +44 1235 445012
CLRC: Rutherford Appleton Laboratory, Chilton, Didcot, OX110QX, UK