Bruno, Given solar_azimuth_angle parallels this definition pretty closely, would you be OK with the originally proposed name if the definition is clear?
john On Jan 15, 2013, at 09:28, Bruno PIGUET wrote: > Aleksandar, > > Thank-you for the clarification. As John said, with the diagram, > everything becomes clear. > > But I fear I have no good suggestion on the way to name this > parameter. Spontaneously, I would say something like > "azimuth_of_sensor_seen_from_observed_point", but, clearly, this doesn't > follow the guidelines for construction of CF Standard Names. > At least, does this correctly reflect what you mean ? > > Bruno. > > > Le 15/01/2013 03:20, Aleksandar Jelenak - NOAA Affiliate a écrit : >> Bruno, John: >> >> platform_azimuth_angle defines an angle where the observation point is >> at the vertex, one side of the angle points north, the other side >> points to the platform, and the angle is calculated clockwise from the >> north. The observation point is defined by an instrument on the >> platform. >> >> Here's one diagram explaining this angle: >> http://science-edu.larc.nasa.gov/SCOOL/images/azimuth.gif >> >> platform_azimuth_angle in the diagram is labelled "Satellite Azimuth >> from North". The observation target is labelled "Where You Are". >> >> I don't agree the definition is weak. It mentions that "platform" >> means the vehicle from which *observations* are made, and clearly >> indicates that *observation target* is at the vertex of this angle. >> Perhaps the confusion is arising from the term "azimuth" as it is >> widely used in ship and airplane navigation. >> >> I opted for "platform" in the name because I saw a standard name >> platform_zenith_angle which can be applied to satellite zenith angles >> and thought to complete the other two missing: satellite scan/look >> angle and satellite azimuth angle by replacing "satellite" with >> "platform". >> >> -Aleksandar >> >> >> On Mon, Jan 14, 2013 at 12:29 PM, John Graybeal <jgrayb...@ucsd.edu> wrote: >>> I agree with Bruno -- platform angle as it is defined in the request is the >>> angle of the _platform_ with respect to a reference direction ("the >>> horizontal angle between the line of sight from the observation point to >>> the platform and a reference direction at the observation point, which is >>> often due north"). The seems like platform orientation to me too. >>> >>> I wasn't excited about the name platform_azimuth_angle anyway, because it >>> is ambiguous on this exact point -- is it the azimuth angle of the >>> platform, or of the instrument on the platform? (the former, in this case). >>> Platform_orientation seems to be the accepted name for the purpose. >>> >>> The definition is very weak though -- can we propose the substitution of >>> this definition for that one? >>> >>> John >>> >>> On Jan 14, 2013, at 09:17, Bruno PIGUET wrote: >>> >>>> Le 14/01/2013 17:21, Aleksandar Jelenak - NOAA Affiliate a écrit : >>>>> Dear Bruno, >>>>> >>>>> On Fri, Jan 11, 2013 at 11:52 AM, Bruno PIGUET <bruno.pig...@meteo.fr> >>>>> wrote: >>>>>> I have one remark about "platform_azimuth_angle" >>>>>> >>>>>> I like this name and it correspond to usual navigation definition (as >>>>>> far as I can tell from my experience with airborne and shipborne >>>>>> measurements), but... >>>>>> >>>>>> There is already a standard name called "platform_orientation", whose >>>>>> definition seems to be the same, even if less precisely-worded : The >>>>>> platform orientation is the direction in which the "front" or >>>>>> longitudinal axis of the platform is pointing (not necessarily the same >>>>>> as the direction in which it is travelling, called platform_course). >>>>> >>>>> platform_orientation is not the same as platform_azimuth_angle. This >>>>> azimuth angle is related to measurements made by an instrument mounted >>>>> on a platform (satellite, ship, airplane, truck, etc.). >>>> >>>> Sorry for looking dumb, but I don't see the difference (except that >>>> "platform_orientation" is not precisely defined). >>>> >>>> I'm currently producing CF files containing airborne measurements, >>>> and the parameter which is usually called "heading", which is in fact >>>> exactly defined as "platform_azimuth_angle", is qualified with >>>> "standard_name = platform orientation". >>>> >>>> Bruno. >>>> -- >>>> bruno.pig...@meteo.fr >>>> Équipe GMEI/TRAMM >>>> CNRM-GAME : UMR Meteo-France/CNRS n°3589 >>>> _______________________________________________ >>>> CF-metadata mailing list >>>> CF-metadata@cgd.ucar.edu >>>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >>>> >>> >>> >>> ---------------- >>> John Graybeal <mailto:jgrayb...@ucsd.edu> phone: 858-534-2162 >>> Product Manager >>> Ocean Observatories Initiative Cyberinfrastructure Project: >>> http://ci.oceanobservatories.org >>> Marine Metadata Interoperability Project: http://marinemetadata.org >>> >>> >>> >>> >>> >>> >>> >>> _______________________________________________ >>> CF-metadata mailing list >>> CF-metadata@cgd.ucar.edu >>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >> _______________________________________________ >> CF-metadata mailing list >> CF-metadata@cgd.ucar.edu >> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > -- > bruno.pig...@meteo.fr > Équipe GMEI/TRAMM > CNRM-GAME : UMR Meteo-France/CNRS n°3589 > _______________________________________________ > CF-metadata mailing list > CF-metadata@cgd.ucar.edu > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ---------------- John Graybeal <mailto:jgrayb...@ucsd.edu> phone: 858-534-2162 Product Manager Ocean Observatories Initiative Cyberinfrastructure Project: http://ci.oceanobservatories.org Marine Metadata Interoperability Project: http://marinemetadata.org _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
