validate projected scene

[matthewhanson]

Check there are valid pixels in the reprojected scene...or else there's little point in reprojecting or saving it

This can happen with SAR, because of the way the mosaics are automatically masked to include only the specific day of interest....if your site falls in a region of the image that has no data it should not project it (or process it even).
Very much related is validation of the output size of the reprojected scene, a check in those cases where there is a mismatch between desired resolution and the SRS (e.g., res in meters and SRS a geographic coordinate system that uses degrees)