ICAO CIRCULAR 326 PDF

INTRODUCTION

The ICAO Separation and Airspace Safety Panel (SASP) undertook an assessment of the use of automatic dependent surveillance — broadcast (ADS-B) and multilateration (MLAT) to provide surveillance to support air traffic services (ATS). The basis of the assessment was a comparison of ADS-B and MLAT to a reference radar. This assessment resulted in the identification of a number of performance requirements (Appendix C1) which must be met for ADS-B or MLAT surveillance to be as good as or better than the reference radar. SASP concluded that ADS-B or MLAT technologies can be used as a means of supporting the provision of ATS surveillance, including separation, in accordance with the requirements in Procedures for Air Navigation Services — Air Traffic Management (PANS-ATM, Doc 4444), Chapter 8.

This circular is a consolidated and single-point reference of the assessment undertaken by SASP and includes:

a) an overview of air traffic control (ATC) surveillance (see Chapter 2);

b) the rationale used by SASP in developing the methodology and arriving at its conclusions (see Chapter 3 and Appendices A and B);

c) the performance requirements attached to the conclusions reached by SASP (see Chapter 3 and Appendices C and D);

d) evidence of the ADS-B and MLAT surveillance performance achieved during several State trials and implementations (see Chapter 3 and Appendices E and F);

e) a compendium of hazards and mitigation measures identified during the development of a safety case to support ADS-B and MLAT trials and implementation (see Chapter 3 and Appendices G and H); and

f) a State implementation roadmap (see Chapter 4).

The roadmap has been included to define the scope and extent of the SASP assessment and also as guidance to assist regions or States undertaking an ADS-B or MLAT implementation safety assessment (see Chapter 3).