I only just located this wikipedia article. It describes the different
axes conventions that are in common use and the differences between them.
https://en.wikipedia.org/wiki/Axes_conventions
On 9/13/18 12:15 PM, Lowry, Roy K. wrote:
>
> Hi John,
>
>
> Your Q2 has been discussed at length.?The local vertical axis is
> indeed?local to the platform, as are the axes running front to back
> and left to right.
>
>
> Your eagle eyes have indeed spotted something I missed in the yaw
> definition ' 'Yaw is a rotation about the axis of rotation' should I
> think?read 'Yaw is a rotation about the local vertical axis'.
>
>
> I HATE 'smart' quotes and Microsoft's mission to make every quote
> smart through auto-correction!
>
>
> Cheers, Roy.
>
>
> I have now retired but will continue to be active through an Emeritus
> Fellowship using this e-mail address.
>
>
>
> ------------------------------------------------------------------------
> *From:* CF-metadata <cf-metadata-bounces at cgd.ucar.edu> on behalf of
> John Graybeal <jbgraybeal at mindspring.com>
> *Sent:* 13 September 2018 16:38
> *To:* CF Metadata List
> *Subject:* Re: [CF-metadata] Platform Heave
> It?s a brilliant effort, if I may say. I?ve been following and
> appreciating it (wanted it for a long time!) and I think it is very close.
>
> If I may say so, it deserves a bit of time for everyone to catch up,
> before enshrinement.? I have two questions I?d like to ask, and one
> editing nit.
>
> Question 1: The last version I found is enclosed, but I can?t tell if
> it is the last version. (Please note the long tails of the emails make
> it extremely time-consuming to find the content when trying to catch
> up. Hence I have sent this without the long tail.)
>
> This version does not seem to address Nan?s suggestion to put the
> platform description after the roll/pitch/etc description, which I
> also like. Still, I can see advantages both ways.
>
> Question 2: The one concern I have, sorry if you dealt with it
> thoroughly, is about the expression in each definition that reads
> something like "Roll is a rotation about an axis that is perpendicular
> to the local vertical axis and is coplanar with the nominal forward
> motion direction of the platform.?? I may be mis-remembering, but from
> my airplane navigation days my understanding is that the role is
> around the axis that points out the front of the airplane. If the
> airplane is pitched up, the roll is around the pitched-up vector; if
> the airplane is yawing to the right, the roll is around the actual
> direction, not the travel direction.? This is important at small
> scales when dealing with the spherical coordinate math necessary to
> point telescopes; it?s important at large scales if you imagine a
> fighter jet flying vertically up or down, and executing a roll (the
> roll axis is definitely not perpendicular to the local vertical axis
> in this case, unless you mean ?platform local?, which I believe is how
> it is defined and I?m pretty sure is how it is measured by the
> accelerometers).? I believe that satellites work the same way
> also?once they define ?front?, the measurements and calculations for
> roll are all around where front is, and similar patterns apply for
> pitch (measured relative to a line perpendicular to front-back axis
> directly through the wings) and yaw (measured around an axis vertical
> to the airplane local?note that the definitions for yaw include "Yaw
> is a rotation about the axis of rotation?, and appear to have lost the
> description of what the axis of rotation *is*.
>
> I cite Wikipedia as my authority, not just because it matches my
> memory but also because it is footnoted, and refers to both airplanes
> and satellites using this reference frame.
>
> Finally, my editing nit is that these definitions have replaced smart
> apostrophes with question marks, I assume dumb apostrophes are the
> order of the day.
>
> John
>
>
>
> platform_roll_starboard_down: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. Roll is a rotation about an axis that is perpendicular to the
> local vertical axis and is coplanar with the nominal forward motion
> direction of the platform. Roll is relative to the ?at rest? rotation
> of the platform with respect to the axis of rotation. The ?at rest?
> rotation of the platform may change over time. "Starboard down"
> indicates that positive values of roll represent the right side of the
> platform falling as viewed by an observer on top of the platform
> facing forward.
>
> platform_roll_starboard_up: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. Roll is a rotation about an axis that is perpendicular to the
> local vertical axis and is coplanar with the nominal forward motion
> direction of the platform. Roll is relative to the ?at rest? rotation
> of the platform with respect to the axis of rotation. The ?at rest?
> rotation of the platform may change over time. "Starboard up"
> indicates that positive values of roll represent the right side of the
> platform rising as viewed by an observer on top of the platform facing
> forward.
>
> platform_roll_rate_starboard_down: Platform is a structure or vehicle
> that serves as a base for mounting sensors. Platforms include, but are
> not limited to, satellites, aeroplanes, ships, buoys, ground stations,
> and masts. "Roll rate" is the rate of rotation about an axis that is
> perpendicular to the local vertical axis and is coplanar with the
> nominal forward motion direction of the platform. Roll rate might not
> include changes to the ?at rest? rotation of the platform with respect
> to the axis of rotation, which may change over time. "Starboard down"
> indicates that positive values of roll rate represent the right side
> of the platform falling as viewed by an observer on top of the
> platform facing forward.
>
> platform_roll_rate_starboard_up: Platform is a structure or vehicle
> that serves as a base for mounting sensors. Platforms include, but are
> not limited to, satellites, aeroplanes, ships, buoys, ground stations,
> and masts. "Roll rate" is the rate of rotation about an axis that is
> perpendicular to the local vertical axis and is coplanar with the
> nominal forward motion direction of the platform. Roll rate might not
> include changes to the ?at rest? rotation of the platform with respect
> to the axis of rotation, which may change over time. "Starboard up"
> indicates that positive values of roll rate represent the right side
> of the platform rising as viewed by an observer on top of the platform
> facing forward.
>
> platform_pitch_fore_up: Platform is a structure or vehicle that serves
> as a base for mounting sensors. Platforms include, but are not limited
> to, satellites, aeroplanes, ships, buoys, ground stations, and masts.
> Pitch is a rotation about an axis that is perpendicular to both the
> local vertical axis and the nominal forward motion direction of the
> platform. Pitch is relative to the ?at rest? rotation of the platform
> with respect to the axis of rotation. The ?at rest? rotation of the
> platform may change over time. "Fore up" indicates that positive
> values of pitch represent the front of the platform rising as viewed
> by an observer on top of the platform facing forward.
>
> platform_pitch_fore_down: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. Pitch is a rotation about an axis that is perpendicular to both
> the local vertical axis and the nominal forward motion direction of
> the platform. Pitch is relative to the ?at rest? rotation of the
> platform with respect to the axis of rotation. The ?at rest? rotation
> of the platform may change over time. "Fore down" indicates that
> positive values of pitch represent the front of the platform falling
> as viewed by an observer on top of the platform facing forward.
>
> platform_pitch_rate_fore_up: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. "Pitch rate" is the rate of rotation about an axis that is
> perpendicular to both the local vertical axis and the nominal forward
> motion direction of the platform. Pitch rate might not include changes
> to the ?at rest? rotation of the platform with respect to the axis of
> rotation, which may change over time. "Fore up" indicates that
> positive values of pitch rate represent the front of the platform
> rising as viewed by an observer on top of the platform facing forward.
>
> platform_pitch_rate_fore_down: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. "Pitch rate" is the rate of rotation about an axis that is
> perpendicular to both the local vertical axis and the nominal forward
> motion direction of the platform. Pitch rate might not include changes
> to the ?at rest? rotation of the platform with respect to the axis of
> rotation, which may change over time. "Fore down" indicates that
> positive values of pitch rate represent the front of the platform
> falling as viewed by an observer on top of the platform facing forward.
>
> platform_yaw_fore_starboard: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. Yaw is a rotation about the axis of rotation. Yaw is relative
> to the ?at rest? rotation of the platform with respect to the axis of
> rotation. The ?at rest? rotation of the platform may change over time.
> "Fore starboard" indicates that positive values of yaw represent the
> front of the platform moving to the right as viewed by an observer on
> top of the platform facing forward.
>
> platform_yaw_fore_port: Platform is a structure or vehicle that serves
> as a base for mounting sensors. Platforms include, but are not limited
> to, satellites, aeroplanes, ships, buoys, ground stations, and masts.
> Yaw is a rotation about the axis of rotation. Yaw is relative to the
> ?at rest? rotation of the platform with respect to the axis of
> rotation. The ?at rest? rotation of the platform may change over time.
> "Fore port" indicates that positive values of yaw represent the front
> of the platform moving to the left as viewed by an observer on top of
> the platform facing forward.
>
> platform_yaw_rate_fore_starboard: Platform is a structure or vehicle
> that serves as a base for mounting sensors. Platforms include, but are
> not limited to, satellites, aeroplanes, ships, buoys, ground stations,
> and masts. "Yaw rate" is the rate of rotation about the axis of
> rotation. Yaw rate might not include changes to the ?at rest? rotation
> of the platform with respect to the axis of rotation, which may change
> over time. "Fore starboard" indicates that positive values of yaw rate
> represent the front of the platform moving to the right as viewed by
> an observer on top of the platform facing forward.
>
> platform_yaw_rate_fore_port: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. "Yaw rate" is the rate of rotation about the axis of rotation.
> Yaw rate might not include changes to the ?at rest? rotation of the
> platform with respect to the axis of rotation, which may change over
> time. "Fore port" indicates that positive values of yaw rate represent
> the front of the platform moving to the left as viewed by an observer
> on top of the platform facing forward.
>
> platform_surge_fore: Platform is a structure or vehicle that serves as
> a base for mounting sensors. Platforms include, but are not limited
> to, satellites, aeroplanes, ships, buoys, ground stations, and masts.
> Surge is a displacement along an axis that is perpendicular to the
> local vertical axis and is coplanar with the nominal forward motion
> direction of the platform. Surge is relative to the ?at rest? position
> of the platform with respect to the axis of displacement. The ?at
> rest? position of the platform may change over time. "Fore" indicates
> that positive values of surge represent the platform moving forward as
> viewed by an observer on top of the platform facing forward.
>
> platform_surge_aft: Platform is a structure or vehicle that serves as
> a base for mounting sensors. Platforms include, but are not limited
> to, satellites, aeroplanes, ships, buoys, ground stations, and masts.
> Surge is a displacement along an axis that is perpendicular to the
> local vertical axis and is coplanar with the nominal forward motion
> direction of the platform. Surge is relative to the ?at rest? position
> of the platform with respect to the axis of displacement. The ?at
> rest? position of the platform may change over time. "Aft" indicates
> that positive values of surge represent the platform moving backward
> as viewed by an observer on top of the platform facing forward.
>
> platform_surge_rate_fore: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. "Surge rate" is the rate of displacement along an axis that is
> perpendicular to the local vertical axis and is coplanar with the
> nominal forward motion direction of the platform. Surge rate might not
> include changes to the ?at rest? position of the platform with respect
> to the axis of displacement, which may change over time. "Fore"
> indicates that positive values of surge rate represent the platform
> moving forward as viewed by an observer on top of the platform facing
> forward.
>
> platform_surge_rate_aft: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. "Surge rate" is the rate of displacement along an axis that is
> perpendicular to the local vertical axis and is coplanar with the
> nominal forward motion direction of the platform. Surge rate might not
> include changes to the ?at rest? position of the platform with respect
> to the axis of displacement, which may change over time. "Aft"
> indicates that positive values of surge rate represent the platform
> moving backward as viewed by an observer on top of the platform facing
> forward.
>
> platform_sway_port: Platform is a structure or vehicle that serves as
> a base for mounting sensors. Platforms include, but are not limited
> to, satellites, aeroplanes, ships, buoys, ground stations, and masts.
> Sway is a displacement along an axis that is perpendicular to both the
> local vertical axis and the nominal forward motion direction of the
> platform. Sway is relative to the ?at rest? position of the platform
> with respect to the axis of displacement. The ?at rest? position of
> the platform may change over time. "Port" indicates that positive
> values of sway represent the platform moving left as viewed by an
> observer on top of the platform facing forward.
>
> platform_sway_starboard: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. Sway is a displacement along an axis that is perpendicular to
> both the local vertical axis and the nominal forward motion direction
> of the platform. Sway is relative to the ?at rest? position of the
> platform with respect to the axis of displacement. The ?at rest?
> position of the platform may change over time. "Starboard" indicates
> that positive values of sway represent the platform moving right as
> viewed by an observer on top of the platform facing forward.
>
> platform_sway_rate_port: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. "Sway rate" is the rate of displacement along an axis that is
> perpendicular to both the local vertical axis and the nominal forward
> motion direction of the platform. Sway rate may not include changes to
> the ?at rest? position of the platform with respect to the axis of
> displacement, which may change over time. "Port" indicates that
> positive values of sway rate represent the platform moving left as
> viewed by an observer on top of the platform facing forward.
>
> platform_sway_rate_starboard: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. "Sway rate" is a displacement along an axis that is
> perpendicular to both the local vertical axis and the nominal forward
> motion direction of the platform. Sway rate may not include changes to
> the ?at rest? position of the platform with respect to the axis of
> displacement, which may change over time. "Starboard" indicates that
> positive values of sway rate represent the platform moving right as
> viewed by an observer on top of the platform facing forward.
>
> platform_heave_up: Platform is a structure or vehicle that serves as a
> base for mounting sensors. Platforms include, but are not limited to,
> satellites, aeroplanes, ships, buoys, ground stations, and masts.
> Heave is a displacement along the local vertical axis. Heave is
> relative to the ?at rest? position of the platform with respect to the
> axis of displacement. The ?at rest? position of the platform may
> change over time. "Up" indicates that positive values of heave
> represent the platform moving up as viewed by an observer on top of
> the platform facing forward.
>
> platform_heave_down: Platform is a structure or vehicle that serves as
> a base for mounting sensors. Platforms include, but are not limited
> to, satellites, aeroplanes, ships, buoys, ground stations, and masts.
> Heave is a displacement along the local vertical axis. Heave is
> relative to the ?at rest? position of the platform with respect to the
> axis of displacement. The ?at rest? position of the platform may
> change over time. "Down" indicates that positive values of heave
> represent the platform moving down as viewed by an observer on top of
> the platform facing forward.
>
> platform_heave_rate_up: Platform is a structure or vehicle that serves
> as a base for mounting sensors. Platforms include, but are not limited
> to, satellites, aeroplanes, ships, buoys, ground stations, and masts.
> "Heave rate" is the rate of displacement along the local vertical
> axis. Heave rate may not include changes to the ?at rest? position of
> the platform with respect to the axis of displacement, which may
> change over time. "Up" indicates that positive values of heave rate
> represent the platform moving up as viewed by an observer on top of
> the platform facing forward.
>
> platform_heave_rate_down: Platform is a structure or vehicle that
> serves as a base for mounting sensors. Platforms include, but are not
> limited to, satellites, aeroplanes, ships, buoys, ground stations, and
> masts. "Heave rate" is the rate of displacement along the local
> vertical axis. Heave rate may not include changes to the ?at rest?
> position of the platform with respect to the axis of displacement,
> which may change over time. "Down" indicates that positive values of
> heave rate represent the platform moving down as viewed by an observer
> on top of the platform facing forward.
>
> platform_course: Platform is a structure or vehicle that serves as a
> base for mounting sensors. Platforms include, but are not limited to,
> satellites, aeroplanes, ships, buoys, ground stations, and masts.
> Course is the clockwise angle with respect to North of the nominal
> forward motion direction of the platform.
>
> platform_orientation: Platform is a structure or vehicle that serves
> as a base for mounting sensors. Platforms include, but are not limited
> to, satellites, aeroplanes, ships, buoys, ground stations, and masts.
> Orientation is the clockwise angle with respect to North of the
> longitudinal (front-to-back) axis of the platform, which may be
> different than the platform course (see platform_course).
>
>
>
>
> ---------------------------------------
> John Graybeal
> jbgraybeal at mindspring.com
> 650-450-1853
> skype: graybealski
> linkedin: http://www.linkedin.com/in/johngraybeal/
> <http://www.linkedin.com/in/johngraybeal/>
> <http://www.linkedin.com/in/johngraybeal/>
>
> John Graybeal - CEDAR/BioPortal Technical ... - LinkedIn
> <http://www.linkedin.com/in/johngraybeal/>
> www.linkedin.com
> View John Graybeal?s profile on LinkedIn, the world's largest
> professional community. John has 6 jobs listed on their profile. See
> the complete profile on LinkedIn and discover John?s ...
>
>
>
>
>
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> ------------------------------------------------------------------------
> This message (and any attachments) is for the recipient only. NERC is
> subject to the Freedom of Information Act 2000 and the contents of
> this email and any reply you make may be disclosed by NERC unless it
> is exempt from release under the Act. Any material supplied to NERC
> may be stored in an electronic records management system.
> ------------------------------------------------------------------------
>
>
> _______________________________________________
> CF-metadata mailing list
> CF-metadata at cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
--
CICS-NC <http://www.cicsnc.org/> Visit us on
Facebook <http://www.facebook.com/cicsnc> *Jim Biard*
*Research Scholar*
Cooperative Institute for Climate and Satellites NC <http://cicsnc.org/>
North Carolina State University <http://ncsu.edu/>
NOAA National Centers for Environmental Information <http://ncdc.noaa.gov/>
/formerly NOAA?s National Climatic Data Center/
151 Patton Ave, Asheville, NC 28801
e: jbiard at cicsnc.org <mailto:jbiard at cicsnc.org>
o: +1 828 271 4900
/Connect with us on Facebook for climate
<https://www.facebook.com/NOAANCEIclimate> and ocean and geophysics
<https://www.facebook.com/NOAANCEIoceangeo> information, and follow us
on Twitter at _at_NOAANCEIclimate <https://twitter.com/NOAANCEIclimate> and
_at_NOAANCEIocngeo <https://twitter.com/NOAANCEIocngeo>. /
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.cgd.ucar.edu/pipermail/cf-metadata/attachments/20180913/b39e0556/attachment-0001.html>
Received on Thu Sep 13 2018 - 12:39:31 BST
