serving multiple orbits as mosaic

[Brent Fraser]

Ara,

  One method you may want to look at is using a TileIndex
Layer for the data
(http://mapserver.gis.umn.edu/docs/howto/raster_data).  In
it's current form, using a TileIndex requires that the index
and all the raster data it references be in the same
coordinate system (e.g. geographic), and the Mapserver will
re-project the data to the coordinate system requested by
the client browser.

  The how-to link given above shows how to use a single
layer to specify the TileIndex ()and the Raster data.    If
you've got a lot of data being added on a daily basis you
may want to use a relational database to store your
TileIndex (but not your raster data). In this case, the way
to set up a TileIndex is with two layers: one (TYPE
TILEINDEX) to define the TileIndex , and another to specify
the raster it contains (TYPE RASTER).

 There are few examples at
http://mapserver.gis.umn.edu/docs/howto/WCSServerFormatHowTo

Brent Fraser
GeoAnalytic Inc.
Calgary, Alberta


----- Original Message ----- 
From: "Ara T Howard" <ara.t.howard at NOAA.GOV>
To: <MAPSERVER-USERS at LISTS.UMN.EDU>
Sent: Friday, February 02, 2007 6:55 AM
Subject: [UMN_MAPSERVER-USERS] serving multiple orbits as
mosaic


> hi all-
>
> we're curently serving dmsp sat data, which are full polar
orbits, as a
> pre-made mosaic.  this works well.
>
> the current projection we're using is geographic which
works well for a large
> marjority of users.  however, it would desirable if one
could actually make a
> request for a polar projection and see, for example, the
aurora ringing the
> pole cap.
>
> unfortunately the fact that we've dumped all the orbits
into a single
> geographic mosaic before hand means that at high/low lats
only one or two
> orbits will be respresented.
>
> i'm still pretty new to mapserver, so perhaps this idea is
simple or
> impossible, but what i'd like to do is server each day's
orbits as layers and
> let mapserver do the mosaicing.  this obviously implies a
request for a bbox,
> multiple layers, and a projection.  the thing is the
client will not know
> which layers are required to cover a particular bbox or in
which order to
> overlay them.  it is possible, however that we could
determine this
> information.
>
> i guess one approach would be to create a pseudo layer
name, say 'F15200701'
> where 'F15' is the satellite and '200701' is the day in
question. the mapfile
> would contain only this pseudo layer name.  once a request
for a bbox and
> projection was made we could dynamically determine which
layers should
> __actually__ be requested and in what order and server
those with the given
> bbox.
>
> does this make any sense?  has anyone out there done
anything similar?
>
> kind regards.
>
> -a
> -- 
> we can deny everything, except that we have the
possibility of being better.
> simply reflect on that.
> - the dalai lama