This service publishes plate scans of the Palomar-Leiden Troian surveys conducted between 1960 and 1977. The surveys led to the discovery of more than 2,000 asteroids (1,800 with orbital information), with another 2,400 asteroids, including 19 Trojans, found after further analysis of the plates.

Note that because of the large size of the plates, in this service each original plate is contained in two parts, marked with "_1" and "_2", respectively. The central parts of the two parts overlap.