Calergin wrote:
...
TCAS only uses slant range (distance from own ship to target) and the
reported mode C (or mode S but that is another story) altitiude. From this
it creates a TAU value, as stated earlier, which is the range over range
rate. When the time to closest approach thresholds are broken depending on
own ships altitiude and state (ie gear down) than alerts and or resolution
advisories are issued.
...

Can you confirm that such a method for resolution advisories may be of little
help when the conflicting aircraft is a glider unable to maintain its altitude
which will rather seem to vary randomly seen from the TCAS equipped aircraft?