Dear John, ----- "John Caron" <[email protected]> wrote:
> The geometry of each point is an interesting wrinkle, and may need > some new conventions. would a rotated ellipse work (3 params) or do we > need a more general polygon? Does it have to be specified per point, > or can is be common to all points? I would imagine that quick > visualizers might ignore the details of this (essentially assuming a > tesselating grid), but more sophisticated and specialized tools would > need this. I do not thing the FOV (field of view) of single "point" should be described as projected on the Earth surface (rotated ellipse and/or polygon) if this is what you meant. It should come as a response function of angular incoming radiation. This response function might be a formula (2D Gaussian, weighted sum of 2D gaussians, etc...) or given as a Look Up Table. The Earth-projected geometry will then be a function of the view angle, Earth topography, integration (photon counting) period, etc... We should definitely be able to have response function varying within the scan array. I think we are entering a terribly complex (and interesting) subject when defining a Feature for those space- and air-borne observational data. The question is then, where should we put the limit in complexity and what is the scope: Do we aim at encoding the "spacecraft instrument engineer" point of view or the "geophysical data user" point of view? Cheers, Thomas _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
