Re: [CF-metadata] Platform Heave

[Kenneth Kehoe]

Roy,

I am specifically asking for platform_sway and platform_surge.

Thanks,

Ken



On 2018-8-6 10:02, Lowry, Roy K. wrote:


Hi Jim,


One other thing to think on is the set of 'rate' Standard Names, or 
are you happy with my prefix from the yaw example added on to your 
definitions.



And finally are we intending to propose platform_sway and 
platform_surge as new Standard Names in addition to platform_heave 
which started this discussion even though nobody has specifically 
asked for them?



Cheers, Roy.


I have now retired but will continue to be active through an Emeritus 
Fellowship using this e-mail address.





*From:* CF-metadata  on behalf of 
Jim Biard 

*Sent:* 06 August 2018 16:47
*To:* CF Metadata List; Jonathan Gregory
*Subject:* Re: [CF-metadata] Platform Heave
Hi.

There are other standard names that call for a separate attribute or 
variable that provides context. The attributes (at the moment) are all 
standard CF attributes (cell_methods, flag_meanings, comment, etc). 
I'd love to get feedback from the community about whether or not a 
directionality attribute would need to described as a "standard" CF 
attribute.


I'll be glad to rework the definitions to make them 
directionality-agnostic when I get back next week.


Grace and peace,

Jim

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On Sat, Aug 4, 2018 at 3:45 AM Lowry, Roy K. > wrote:


Dear Nan,


So are we returning to the wording in Alison's original
definitions (e.g. yaw normally clockwise facing front) before
you with my support asked for the ambiguity be removed? Or do you
want to go even further with no mention of sign convention at all?


I would also question whether a Standard Name definition is the
place to specify the mechanism to be used for the description of a
sign convention as it has wider implications than the parameters
currently under discussion. Would it not be more appropriate for
this to be considered an enhancement to CF and written into the
Conventions document? If so, it should it not be the subject of a
GitHub ticket?


Cheers, Roy.


I have now retired but will continue to be active through an
Emeritus Fellowship using this e-mail address.

Re: [CF-metadata] Platform Heave

[Lowry, Roy K.]

Hi Jim,


One other thing to think on is the set of 'rate' Standard Names, or are you 
happy with my prefix from the yaw example added on to your definitions.


And finally are we intending to propose platform_sway and platform_surge as new 
Standard Names in addition to platform_heave which started this discussion even 
though nobody has specifically asked for them?


Cheers, Roy.


I have now retired but will continue to be active through an Emeritus 
Fellowship using this e-mail address.



From: CF-metadata  on behalf of Jim Biard 

Sent: 06 August 2018 16:47
To: CF Metadata List; Jonathan Gregory
Subject: Re: [CF-metadata] Platform Heave

Hi.

There are other standard names that call for a separate attribute or variable 
that provides context. The attributes (at the moment) are all standard CF 
attributes (cell_methods, flag_meanings, comment, etc). I'd love to get 
feedback from the community about whether or not a directionality attribute 
would need to described as a "standard" CF attribute.

I'll be glad to rework the definitions to make them directionality-agnostic 
when I get back next week.

Grace and peace,

Jim

[CICS-NC]Visit us on
FacebookJim Biard
Research Scholar
Cooperative Institute for Climate and Satellites NC 
North Carolina State University 
NOAA National Centers for Environmental Information 
formerly NOAA’s National Climatic Data Center
151 Patton Ave, Asheville, NC 28801
e: jbi...@cicsnc.org
o: +1 828 271 4900

Connect with us on Facebook for 
climate and ocean and 
geophysics information, and follow us 
on Twitter at @NOAANCEIclimate  and 
@NOAANCEIocngeo.




On Sat, Aug 4, 2018 at 3:45 AM Lowry, Roy K. 
mailto:r...@bodc.ac.uk>> wrote:

Dear Nan,


So are we returning to the wording in Alison's original definitions (e.g. yaw 
normally clockwise facing front) before you with my support asked for the 
ambiguity be removed? Or do you want to go even further with no mention of sign 
convention at all?


I would also question whether a Standard Name definition is the place to 
specify the mechanism to be used for the description of a sign convention as it 
has wider implications than the parameters currently under discussion. Would it 
not be more appropriate for this to be considered an enhancement to CF and 
written into the Conventions document? If so, it should it not be the subject 
of a GitHub ticket?


Cheers, Roy.


I have now retired but will continue to be active through an Emeritus 
Fellowship using this e-mail address.



From: CF-metadata 
mailto:cf-metadata-boun...@cgd.ucar.edu>> on 
behalf of Nan Galbraith mailto:ngalbra...@whoi.edu>>
Sent: 04 August 2018 02:18
To: cf-metadata@cgd.ucar.edu
Subject: Re: [CF-metadata] Platform Heave

Thanks, Jim.

> change the definitions to avoid declaring which direction is
> positive, make the direction attribute optional, and say that users
> should be careful about assuming the directionality for variables
> lacking the attribute.

This is the approach I'd prefer as well.

- Nan


Quoting Jim Biard mailto:jbi...@cicsnc.org>>:

> Nan,
>
> I didn't go to the lengths of making new regularized definitions
> before I wrote that list. I was thinking in terms of making the
> clockwise/anticlockwise call based on the right hand rule and the
> unit vector for each axis. For roll, for example, if the X unit
> vector faces forward, the "right side down" roll is actually
> anticlockwise - that is, it is in the direction that your right hand
> fingers curl if you grab the unit vector in your hand with your
> thumb pointing in the same direction as the unit vector. That
> definition is independent of observer location and look direction.
> My definitions for all the direction values are following that same
> convention.
>
> Accurate knowledge of the sign of roll, pitch, and yaw is critical
> in the satellite and aircraft world. The look angles for remote
> sensors are affected by these values. I get it that not all systems
> care about the signed values, so that reason and for backward
> compatibility I suggested that we could change the definitions to
> avoid declaring which direction is positive, make the direction
> attribute optional, and say that users should be careful about
> assuming the directionality for variables lacking the attribute.
>
> Grace and peace,
>
> Jim
>>
>> On 8/3/18 2:03 PM, Nan Galbraith wrote:
>>> Hi Roy -
>>>
>>> Yes,  I've been looking at that page quite a bit lately, and I
>>> think it backs up
>>> what I'm saying.
>>>
>>> If you are standing on that fuselage (may we never), facing
>>> forward, the red roll
>>> 

Re: [CF-metadata] Platform Heave

[Jim Biard]

Hi.

There are other standard names that call for a separate attribute or
variable that provides context. The attributes (at the moment) are all
standard CF attributes (cell_methods, flag_meanings, comment, etc). I'd
love to get feedback from the community about whether or not a
directionality attribute would need to described as a "standard" CF
attribute.

I'll be glad to rework the definitions to make them directionality-agnostic
when I get back next week.

Grace and peace,

Jim

[image: CICS-NC] Visit us on
Facebook  *Jim Biard*
*Research Scholar*
Cooperative Institute for Climate and Satellites NC  
North Carolina State University  
NOAA National Centers for Environmental Information  
*formerly NOAA’s National Climatic Data Center*
151 Patton Ave, Asheville, NC 28801
e: jbi...@cicsnc.org
o: +1 828 271 4900

*Connect with us on Facebook for climate
 and ocean and geophysics
 information, and follow us on
Twitter at @NOAANCEIclimate
and @NOAANCEIocngeo
.*



On Sat, Aug 4, 2018 at 3:45 AM Lowry, Roy K.  wrote:

> Dear Nan,
>
>
> So are we returning to the wording in Alison's original definitions (e.g.
> yaw normally clockwise facing front) before you with my support asked for
> the ambiguity be removed? Or do you want to go even further with no mention
> of sign convention at all?
>
>
> I would also question whether a Standard Name definition is the place to
> specify the mechanism to be used for the description of a sign convention
> as it has wider implications than the parameters currently under
> discussion. Would it not be more appropriate for this to be considered an
> enhancement to CF and written into the Conventions document? If so, it
> should it not be the subject of a GitHub ticket?
>
>
> Cheers, Roy.
>
>
> I have now retired but will continue to be active through an Emeritus
> Fellowship using this e-mail address.
>
>
> --
> *From:* CF-metadata  on behalf of Nan
> Galbraith 
> *Sent:* 04 August 2018 02:18
> *To:* cf-metadata@cgd.ucar.edu
> *Subject:* Re: [CF-metadata] Platform Heave
>
> Thanks, Jim.
>
> > change the definitions to avoid declaring which direction is
> > positive, make the direction attribute optional, and say that users
> > should be careful about assuming the directionality for variables
> > lacking the attribute.
>
> This is the approach I'd prefer as well.
>
> - Nan
>
>
> Quoting Jim Biard :
>
> > Nan,
> >
> > I didn't go to the lengths of making new regularized definitions
> > before I wrote that list. I was thinking in terms of making the
> > clockwise/anticlockwise call based on the right hand rule and the
> > unit vector for each axis. For roll, for example, if the X unit
> > vector faces forward, the "right side down" roll is actually
> > anticlockwise - that is, it is in the direction that your right hand
> > fingers curl if you grab the unit vector in your hand with your
> > thumb pointing in the same direction as the unit vector. That
> > definition is independent of observer location and look direction.
> > My definitions for all the direction values are following that same
> > convention.
> >
> > Accurate knowledge of the sign of roll, pitch, and yaw is critical
> > in the satellite and aircraft world. The look angles for remote
> > sensors are affected by these values. I get it that not all systems
> > care about the signed values, so that reason and for backward
> > compatibility I suggested that we could change the definitions to
> > avoid declaring which direction is positive, make the direction
> > attribute optional, and say that users should be careful about
> > assuming the directionality for variables lacking the attribute.
> >
> > Grace and peace,
> >
> > Jim
> >>
> >> On 8/3/18 2:03 PM, Nan Galbraith wrote:
> >>> Hi Roy -
> >>>
> >>> Yes,  I've been looking at that page quite a bit lately, and I
> >>> think it backs up
> >>> what I'm saying.
> >>>
> >>> If you are standing on that fuselage (may we never), facing
> >>> forward, the red roll
> >>> arrow is showing a clockwise motion, with right side moving
> >>> downward. If you
> >>> were facing aft, the arrow would be anticlockwise, but the right side
> would
> >>> be rising.
> >>>
> >>> So, 'roll: "clockwise" for positive right side up and
> >>> "anticlockwise" for positive right
> >>> side down'- is backwards in either case. I'm not disputing
> >>> anything except
> >>> the term 'clockwise'  in this phrase.
> >>>
> >>> Thanks - Nan
> >>>
> >>> On 8/3/18 1:43 PM, Lowry, Roy K. wrote:
> 
>  Hi Nan,
> 
> 
>  Whilst I appreciate the limitations of Wikipedia as an
>  authoritative source have a look at
>  https://en.wikipedia.org/wiki/Aircraft_principal_axes
>