I am not sure about that, but I do know that the Apollo astronauts used
a gnomon on the moon strictly as a scale for documenting moon rock
samples. This gnomon also had a color chart for film calibration.
I use a variant of this to take architectural photographs in the sign
business, using a three foot tall marked stick as a known scale.

Matthew Ota

W. Watson wrote:

In a book on prehistoric astronomy, the author describes the use of a
gnomon to determine E-W from the sun. One drives a stick, the gnomon,
into the ground and marks the tip of the shadow of the sun. Then
sometime later this is done again. A line drawn through the two points
is E-W. So my questions are 1. how accurate is this method and 2. who
was the first to discover it, and 3. when was it discovered it?