2.1.  The air navigation service providers shall define performance requirements for the accuracy, availability, integrity, continuity and timeliness of the surveillance data provided by the systems referred to in Article 4(3) and used to enable the surveillance applications conducted.

2.2.  The evaluation of the accuracy of the horizontal position provided by the systems referred to in Article 4(3) shall include, as a minimum, the assessment of horizontal position error.

2.3.  The air navigation service providers shall verify compliance with the performance requirements defined in accordance with points 2.1 and 2.2.

2.4.  Verification of compliance shall be performed on the basis of the surveillance data provided at the output of the surveillance chain, to the surveillance data user.