# Parallax calculation

Given two points of observation on Earth (obs1=[lat1,lon1], obs2=[lat2,lon2]) and the apparent azimuth and altitude of a target from these two locations (obs1=[az1,alt1], obs2=[az2,alt2]), how can I calculate the parallax distance to target? (the separation between the observation points is about 1 Km).

Thanks.

• You also need the height of those observation points and instead of altitude for the target you need the range. You should also need the elevation of the target. – Mefitico Sep 25 '19 at 12:38