In the drawings and descriptive narrative there are usually three figures from the surveys given for the site. The azimuth is the bearing from true north, in degrees, of the line which the site indicates. If there is any ambiguity in the site a band of bearings from left to right is given. The second figure given is the altitude , which is the horizon height, in degrees, of the point on the horizon which the azimuth line indicates. The azimuth and corrected altitude, with the latitude of the site, can be used to calculate the declination , which is the third figure given.
Declination is another term for celestial latitude.
This is because the declination value of the sun and the moon for any significant event is known. The declination of a star does not change much in a human lifetime. However, the declination of the sun and the moon change from day to day. The declination figure is useful because the sun at its key points in the year always assumes the same declination values. These are the modern values.