All FOVs are determined using a spherical Earth unless otherwise stated. COVE uses instrument FOVs to create ground swaths.
Along-track swath extents are not modeled. COVE does not have sufficient mission operation information to determine when future images will be acquired and any instrument pointing at the time of acquisition. Instead, COVE segregates swaths into 1 minute pieces. Many along-track swath extents are smaller than this distance. For more information read the technical paper referenced on the home page.
Missions that are notional utilize a J2 Propagator to determine the orbit up to the exact ground track repeat of the satellite. The orbit position is then determined by COVE by using the same position on a certain date and time to determine the future.
Orbit maneuvers are not considered by COVE. The TLE data is the only insight that COVE has into any maneuvers that may have been performed. COVE will only make the necessary corrections to the orbit if the TLE data exists after the maneuver.
Currently, limb viewers are modeled as nadir pointing instruments inside of COVE. If an instrument has limb-to-limb viewing capability, we had to assume a very large swath width determined from the altitude of the mission and leave it constant.
Along-track pointing is not currently modeled in COVE.
Viewing angles are determined from the closest approach of the nadir/boresight point to the ground point or region edges. This is done because we do not have insight as to when an image is actually going to be captured and where the region or point will be in along-track direction inside of the image. We assume point exactly to the left or right of nadir/boresight.