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

[Petr Skoda]

I did not want to start this off-topic, but it may be the conceptual 
misunderstanding which confirms my previous post (sorry I should have been 
more specific to explain what is wrong from my point of view).

It is probably the example of conflicts between the VO developer (who 
tries to make the tool interoperable, elegant, consistent ....) and the 
ordinary astronomer, who is usually the expert in his field but is not a 
IT geek and should be considered strongly conservative (and hardly ever 
wants to read manuals ;-)

  If the tool does not fit his expectations (and conceptual model of his 
thinking ) he has a strong tendency to disregard it however productive, 
efficient etc it is just due to (from our point of view) the subtle and 
weird reasons ..

Its a experience I have made during my career with many stellar 
astronomers (from all over the world - usually they came from small 
observatories, university departments etc .... ) trying to convince them 
to use the  VO for their research, giving lectures and showing them the 
power of VO tools.

E.g. when I convinced one of this collegue to try both VOSpec and SPLAT, 
he had after 10 minutes of trial preferred SPLAT (just after trying to get 
spectrum of his favourite star from archives he had known it must be 
there). The reason was as I stated in last mail.

He wrote the coordinates in both tools, got some numbers and queried 
archives. The result was that SPLAT has found the observations, the VOSpec 
not. So next trial was Vega (looking in some table of his targets and 
calibration objects he wrote directly coordinates).

It was even worse- the Elodie archive returned something strange - some 
very cold star.

The result was -  "it seems not to work - perhaps it needs still some 
tuning !!"

The SPLAT returned what he wanted immediately.

> Petr wrote:
>> The VOspec allows only degrees but if you enter the H:M:S representation
>> it makes strange numbers and performs the query of strange coordinates
>> (no complain).

Again - I do not have any  complaints
  about functionality of VOSpec - it is strictly designed as VO  tool and 
requires the kind of VO habits (if you stay longer at the input field it 
writes hint:
"Right Ascention  in degrees" - its OK but who will bother to convert just 
to see something working ;-)

> the strange coordinates you mention are in degrees, my friend!
That is the point !! 99% people will expect this to be  DECIMAL HOURS !!!!
(despite the long periodic number that usually fills the input field after 
conversion - which prevents to see the beginning of the number- he can 
check the param tree and see tre POS )

  > VOSpec admits the following 
string coordinates formats for RA: >
> DD:MM:SS.SSS
> 18:36:56.336 is 18degrees, 36 minutes, 56.336 seconds (degrees are the
> default)
Nice but its not RA of Vega !


>
> DDh:MM:SS.SSS
> 18h:36:56.336 is 18hours, 36 minutes, 56.336 seconds,
> (transformed to 271.538933333333 degrees by VOSpec)

This is OK - but you have to be very clever to find the trick (and read 
manual ;-) Perhaps the habit from IRAF (people are lazy to add additional 
h)

Its about the expectations, habits etc ... !

> This is described in the VOSpec help pages

As I said - everything is fine - but VO will have success only if it will 
be natural to use the VO tools as legacy tools (biased by the environment 
and community optical say  X-ray,  radio, optical )


I would not stay with this issue longer - its a problem for me to stay 
independent enough ;-) at the boundary between the VO developers and 
(conservative) users - I understand both sides but its difficult to 
explain to the other group the reasons why something is such and not as 
they expect......

Perhaps we can postpone this discussion to some nice pub in Strasbourg ;-)

Best regards,

Petr Skoda

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*  Petr Skoda                         Phone : +420-323-649201, ext. 361 * 
*  Stellar Department                         +420-323-620361           *
*  Astronomical Institute AS CR       Fax   : +420-323-620250           *
*  251 65 Ondrejov                    e-mail: skoda at sunstel.asu.cas.cz  *
*  Czech Republic                                                       *
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