luna-brainstorming

Luna Brainstorming

Andy Mabbett

Proposal

I propose a "luna" microformat, for marking up co-ordinates on our Moon. This would be based on the "geo" microformat (and thus relatively easy to implement, since code for "geo" can be re-used).

Note, though, that [1] and [2] indicate that more than one system of recording the co-ordinates, for any given point, is in use, and it may be necessary to include an attribute to indicate which system is to be used, though the most recent standards appears to be the IAU Mean Earth Polar Axis co-ordinate system, as used by NASA and Wikipedia, and described in Davies and Colvin, J. Geophys. Res., v. 105, pp. 20,227 - 20,280, 2000.

Kevin Marks

Note multiple statements of Apollo landing co-ords here: [3]

"Currently, the lunar geoid is being redefined with Clementine data, so the location (latitude, longitude, and elevation) of everything will change again very soon".

I believe the reference geoids for other planets are also under revision

• True, but there are also other reference systems for Earth too

Drew McLellan

Perhaps geo could be extended to encompass multiple grids. The existing type/value system in hCard et al could be used. Available types would intially be 'Earth', 'Luna', 'Mars', with the default (if none is specified) being 'Earth'. These could be extended to add new grids when needed. The value is then the co-ordinate.

Obviously the name 'geo' applies to Earth, but we should seriously consider if we want to create a different microformat for every lump of rock someone wishes to map. It has to be advantageous to have a single format for this function that can be applied to any orbiting mass.

• How would an existing user agent parse the grid ref.s for somewhere on the moon, marked up this way? - Andy Mabbett
  • Badly, I'd imagine. However, it's easier to modify user agents to account for developments than a bulk of existing published data - Drew.
    • What published data would need to be modified? (Either way, I like the idea of an hCard for 'Ed Straker, SHADO, Moonbase 1, the Moon'. Maybe we need to add a "solar system" attribute... ;-) ) - Andy Mabbett
• Perhaps, like Drew McLellan points out, there should be a more general class for marking that this is a "coordinate", or a "location". Then a specific reference frame or spatial body can be defined. However, this may only happen once per document and then the rest of the locations references should/could be assumed to be in the same reference frame - AndrewTurner

AndrewTurner

I think we should keep it simple, and also follow the same format used for marking Home/Work for adr, etc. which uses the class="type"

<span class="geo">
 <span class="latitude">37.386013</span>, 
 <span class="longitude">-122.082932</span>
 <span class="type">moon</span>
</span>

This would also apply to Earth-centric coordinate representations such as WGS84, NAD, ED50, etc.

<span class="geo">
  <span class="type" title="moon">The Apollo 11 mission landed at </span>
  <abbr class="latitude" title="0.67408">the Sea of Tranquility</abbr>
  <abbr class="longitude" title="23.47297"></abbr >
</span>

• The value must be "luna" not "moon". "Luna" is the scientifically-correct name for our moon; there are other moons in our solar system, such as Titan. I have two concerns about re-using "geo" (aside from the fact that it means "Earth"!) - how it will affect existing tools, and the likely need to also specify the coordinate schema. Can these be addressed satisfactorily? - Andy Mabbett

See also

• luna-examples
• geo
• mars
• geo-extension-strawman - a possible implementation new!