Coordinate Systems - Help

[theexcession]

Hi, I have some XML data that *should* allow me to render hexagons representing the spot beams from a satellite as they shine down onto the Earth's surface.

Only problem is for each Hexagon I've got six data points

e.g.

<Vertex ID="1">38277</Vertex>
<Vertex ID="2">39355</Vertex>
<Vertex ID="3">39351</Vertex>
<Vertex ID="4">37909</Vertex>
<Vertex ID="5">36831</Vertex>
<Vertex ID="6">36835</Vertex>

and

<Vertex ID="1">52034</Vertex>
<Vertex ID="2">53111</Vertex>
<Vertex ID="3">54548</Vertex>
<Vertex ID="4">52009</Vertex>
<Vertex ID="5">49485</Vertex>
<Vertex ID="6">49855</Vertex>

but does anyone have any clue as to what sort of coordinate system this might be.

The rfp says:
The format of the data for the spot beam map uses an xml structure with each of the six edge point of the map defined.

Unfortunately thr customer is away at the moment so I was hoping one of you guy's might be able to help.

cheers
Ex

[zumbruk]

Idle curiousity led me to some Googling, and a search for "Spherical grid data model hexagon" seems to, er, have caused my brain to leak out of my ears and soak into my shirt ...

[theexcession]

zumbruk said:

Idle curiousity led me to some Googling, and a search for "Spherical grid data model hexagon" seems to, er, have caused my brain to leak out of my ears and soak into my shirt ...

no shit

I finally figured it out:

Vertex = [360(φ+90)]+θ+180
where:
φ := Latitude in degrees, rounded to the nearest integer with
(90°S ≡ -90) ≤ φ ≤ (90 ≡ 90°N)
and:
θ := Longitude in degrees, rounded to the nearest integer with
(180°W ≡ -180) ≤ θ ≤ (179 ≡ 179°E)


best
Ex


>> Edited by theexcession on Monday 18th July 15:41

[ATG]

kinell ... makes great sense to encode the coordinates that way if you're then going to express them in unicode text in a bleeding XML file ... world has gone mad