AMOSSG/4-SN No. 3

26/6/03

AERODROME METEOROLOGICAL OBSERVING SYSTEMS STUDY GROUP (AMOSSG)

FOURTH MEETING

Montreal, 15 to 18 September 2003

Agenda Item	6:	Capability of automatic observing equipment to meet aeronautical requirements

OVERVIEW OF PAST AND EXPECTED PROGRESS WITH RESPECT TO ASSESSMENTS OF THE CAPABILITY OF AUTOMATIC OBSERVING EQUIPMENT TO MEET AERONAUTICAL REQUIREMENTS

(Presented by the Secretary)

SUMMARY
A brief summary of the past progress made by the group is given with respect to the assessment of the capability of automatic observing systems to meet aeronautical requirements together with an overview of outstanding tasks for consideration by the group.

1.	INTRODUCTION

1.1	This paper summarizes the tasks that are under review by the group that concern the assessment of the capability of automatic observing systems to meet the aeronautical requirements together with an indication of previous discussions and in some cases suggested courses of future action.

2.	DISCUSSION

2.1	Assessment of the capability of automatic weather stations to meet the future requirements

2.1.1	The group will recall that no new developments were reported at the AMOSSG/3 Meeting and, as a consequence, no proposals were made regarding Amendment 73 to Annex 3 — Meteorological Service for International Air Navigation in connection with the ability of fully automatic observing systems meeting the aeronautical requirements. It was agreed that whilst substantial progress had been made in the area of automation, further effort would be required before fully automatic systems could be used in lieu of human observers.

2.1.2	It is expected that members of the group will present reports on any progress made in the area of automation together with any recommendations concerning the capability of such systems to meet the aeronautical requirement.

2.1.3	A brief overview of the status that was agreed at the AMOSSG/3 Meeting is given below together with comments, as necessary.

Visibility

2.1.4	It was agreed that visibility was the only one of the critical elements given that could be observed using fully automatic observing equipment so as to meet the current aeronautical requirements. However, the group may wish to note that additional guidance may be required in the proposed manual on the use of automatic observing systems in the light of draft Amendment 73 to Annex 3 which calls for the use or prevailing visibility in aerodrome reports.

Cloud amount

2.1.5	Some members of the group believed that cloud amount could be assessed by fully automatic equipment whilst this view was not shared by the whole group who felt that difficulties were still being experienced under certain circumstances. Therefore, the group agreed that some work was still required concerning the harmonization of the techniques used. To this extent the MET Divisional Meeting (2002) (Recommendation 2/4 refers) invited the World Meteorological Organization (WMO) to study the possibility of producing standard algorithms for cloud amount as well as the height of cloud base. A report is expected from Saad (WMO) outlining how this study is to be progressed by WMO.

Cloud type (CB, TCU)

2.1.6	The group will recall that progress in the automatic detection of cloud type has been a separate task in the work programme of the group since the METLINKSG/1 Meeting. As such, members are invited to submit reports on any progress made and to make an assessment of the capabilities of automatic systems in this area. The group may wish to consider the relevance of considering the automatic detection of cloud type in the work programme as a separate item and may wish to agree that it should be included under the general task of assessing the capabilities of automatic observing systems.

Present and recent weather

2.1.7	Members of the group are invited to submit reports on progress made in the automatic reporting of present weather and recent weather. The group may wish to bear in mind discussions under Agenda item 5 whereby the requirements were considered.

Summary

2.1.8	The group may wish to review the overall assessment made at the AMOSSG/3 Meeting whereby it was agreed that visibility was the only element above that could, at that time, be reported using fully automatic systems. The group is expected to re-evaluate all of the elements discussed above with a view to agreeing the current position and, if necessary, proposing changes to Annex 3 to accommodate the new position.

2.2	The use of fully automatic systems during operational hours (Agenda item 5)

2.2.1	The group may wish to reconsider the issue of the use of fully automated systems during operational hours in the light of any discussions under this Agenda item.

3.	ACTION BY THE GROUP

3.1	The group is invited to;

a)	agree that the automatic detection of cloud type should be considered under the general task of "assessing the overall capabilities of automatic observing systems in meeting the aeronautical requirements" in the work programme of the group;

b)	consider whether changes to Annex 3 are required in order to reflect changes in the capabilities of fully automatic systems to report the various meteorological elements in lieu of human observers, and

c)	consider whether the issues discussed under this Agenda item warrant any changes to the group's position on the use of fully automatic systems during operational hours.

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