Does "HD" mean both 720p and 1080i? Where does 480i and 480p fit in? Are SD broadcasts 480i on satellite and less than 480i on cable and OTA antennas? Is one difference between 480i and 480p that 480p is in widescreen (e.g., the Superbowl and the show ER)? If I get better clarity on my local SD channels through my OTA antenna compared to my dish, does that mean that the OTA VHF broadcast has higher resolution than the satellite? I'm thinking "no".