How do I indicate origin and accuracy of new location coordinates?

If coordinates are sourced directly from another publication, this should be clearly indicated by adding a reference on the "location" resource. To indicate the horizontal accuracy (when known) or in cases where coordinates have been derived through analysis of maps or spatial imagery, Pleiades uses a special document called an "accuracy assessment". There is already a stock imagery assessment document in the Pleiades system that can be re-used when coordinates have been determined through analysis of imagery in Google Earth. 

To view a short video demonstrating how to add an existing imagery assessment document to a location resource, see http://youtu.be/g-H6Tn87hyc.