Assertion: ufo | /r/HasProperty | made against blank sky
Facets:
value: to set a maximum distance
type: PURPOSE
value: often
type: TEMPORAL
value: with no background object
type: OTHER
Source sentences:
text: Visual impressions of distance and speed of UFOs are also highly unreliable because they are based on an assumed size and are often made against a blank sky with no background object (clouds, mountains, etc.) to set a maximum distance.
text: Visual impressions of distance and speed of UFOs are also highly unreliable because they are based on an assumed size and are often made against a blank sky with no background object (clouds, mountains, etc.) to set a maximum distance.