All three are acceptable direct-to-home satellite broadcast standards. But that's all they are. The document does not define them as high definition, and citing it only serves to muddy the issue.http://www.atsc.org/standards/a81.html
This page lists the 3 standards for 1080. There is a chart on page 17 (Chart 7.3) giving all the accepted standards for 1080 ATSC Direct-to-Home Broadcasts over satellite. Not only are all three acceptable for 1080i but also for 1080p.
The ATSC has only defined two resolutions as HD: 1080x1920 and 720x1280. That's it. There aren't any others.
Scott