[CF-metadata] how to store satellite groundpixel geometry?

From: Aleksandar Jelenak - NOAA Affiliate <aleksandar.jelenak>
Date: Wed, 20 Mar 2013 23:26:02 -0400

Hello Andreas,

On Wed, Mar 20, 2013 at 5:50 PM, Andreas Hilboll <lists at hilboll.de> wrote:
> I was wondering if it is possible to describe the pixel geometry of
> satellite measurements in CF. In atmospheric trace gas remote sensing,
> an individual measurement's location is often described by the center
> point's lat/lon coordinates plus the four pixel corner points' lat/lon
> coordinates. One measurement's location is thus described by a total of
> five lat/lon points.

I am not clear in what form is your data. Is it still in the sensor's
field-of-view projection (swath) or already massaged into a grid. You
mention "pixel corner points", that sounds like a grid. Typical sensor
field-of-view projection onto the Earth geoid is an ellipse so no real
corners there.

If it is gridded then CF is your friend. The convention does not yet
have a standard representation for satellite swath data. The
trajectory feature type is one way of improvising some types of swath
data if each observation is done at a different time.

> If it were only the center point, then I would know how to use a
> "discrete sampling geometry" with a "trajectory" feature.
>
> How can I describe the four corner points?

Not in a standard way. Your new variables holding lat and lon corner
points must share the dimension used for the trajectory points: the
"observation" dimension.

       -Aleksandar
Received on Wed Mar 20 2013 - 21:26:02 GMT