What is the accuracy of predictions using the two-line element sets?
Accuracy of the two-line element sets is dependent upon a number of factors. These range from the particular sensors used and amount of data collected to the type of orbit and condition of the space environment. Unfortunately, since these factors vary for each element set, so does the accuracy. While NORAD has experimented with methods to incorporate prediction quality into the element sets, none of these methods has yet proved successful.