scope:

INTRODUCTION

The purpose of this manual is to help design or update automatic measurement systems for airports and understand the characteristics and limitations of such systems. The manual also deals with performance control and maintenance, as well as with maintaining the optimum operating conditions.

The chapters in this manual are organized according to parameter type and are presented in the same order as Annex 3 - Meteorological Service for International Air Navigation, Chapter 4 and Appendix 3.

The objective of this manual is not to describe all possible measurement methods; WMO's Guide to Meteorological Instruments and Methods of Observation (WMO-No. 8), which is regularly reviewed and revised by WMO as necessary, describes these methods in detail. This manual takes this Guide into account but describes only those aspects which are useful or specific to the field of aeronautical meteorology.

The Manual of Runway Visual Range Observing and Reporting Practices (Doc 9328) describes all aspects related to runway visual range (RVR) and, to a large extent, visibility. This manual therefore does not go into detail about those elements.

The automatic observation of clouds and present weather is a new area of study and cannot yet meet all the needs expressed in Annex 3. The algorithms used are constantly evolving, making it difficult to standardize them at the present time. As a result, this manual indicates the basic principles only.