Since we are going off topic and talking about capturing a glideslope from above, I'd just like to ask a quick question. Has anyone ever captured a false glideslope? I've captured from above numerous times but never been 100% high, which is what would be required to do it if I remember correctly. Also, I don't see how any normal jet airliner could maintain the glide on that profile.
Edit: Found this which makes a false GS capture even more unlikely.
False signals may be generated along the glide slope in multiples of the glide path angle, the first being approximately 6º degrees above horizontal. This false signal will be a reciprocal signal (i.e. the fly up and fly down commands will be reversed). The false signal at 9º will be oriented in the same manner as the true glide slope. There are no false signals below the actual slope. An aircraft flying according to the published approach procedure on a front course ILS should not encounter these false signals.