This is the first edition of the Manual on the WMO Integrated Global Observing System (WMO-No. 1160), developed following the decision of the Sixteenth World Meteorological Congress to proceed with the implementation of that System (WIGOS). It was approved by the Seventeenth World Meteorological Congress. The Manual was developed by the Executive Council through its Inter-Commission Coordination Group on WIGOS, specifically its Task Team on WIGOS Regulatory Material. It is the result of a collaborative approach involving all interested technical commissions under the leadership of the Commission for Basic Systems (CBS) and the Commission for Instruments and Methods of Observation (CIMO). The Manual is designed: (a) To specify the obligations of Members in the implementation and operation of WIGOS

(b) To facilitate cooperation in observations between Members

(c) To ensure adequate uniformity and standardization in the practices and procedures employed in achieving (a) and (b) above.