Digital NOTAM Proposal

Introduction

In the AIS data chain, the "originator" role is identified as that organisation/entity that initiates a change in the aeronautical information/data by identifying or by deciding to change that results in changes in aeronautical data subjects and/or properties. In the case of Digital NOTAM, the typical originators are the same as for the current text NOTAM - the airport managers, the airspace/procedure designers, the national authorities, the CNS. ATC. ATFM service providers, etc.

In the current NOTAM environment, the term "NOTAM Proposal" is used to identify the information artefact that is provided by a NOTAM originator towards the responsible NOTAM office. This can range from a simple phone call ("we need to close runway x until tomorrow morning") up to an almost completely formatted NOTAM message.

A similar concept applies for Digital NOTAM. The purpose of this page is to explain the different options that exist for Digital NOTAM origination, in particular when using AIXM and the Event extension for coding the data exchanged between the data originators and the AIS/NOTAM office.

Digital NOTAM Proposal - options

Regular - digital coding of the Event data

In this case the data originator has access to the baseline digital data set and has the capacity to fully digitally code the Event, including any necessary feature TimeSlice for the scenario. The Digital NOTAM proposal will include as a minimum:

all necessary Feature Timeslices (TEMPDELTA, BASELINE - as applicable)
the Event(s) to which these TimeSlices are associated, including as a minimum the scenario. Additional properties could be included, such as estimatedValidity, activity, name, designator, etc. This could also include associations between Events (cause, parent).

Note: if the originator also provides the NOTAM/SNOWTAM/ASHTAM object, the receiving Digital NOTAM application might choose to ignore this data and to re-generate the NOTAM using the corresponding scenario production rules.

Minimal - textual description of the Event

In this case the data originator does not have the capacity to fully digitally code necessary feature TimeSlice for the scenario, but has the capability to code an Event. This could be the case when using a relatively simple, web-based HMI for Digital NOTAM origination. In this case, the feature and condition data is provided as free text, using the Event summary property. This will be presented as text to the Digital NOTAM operator in order to do the complete the encoding and to also generate the NOTAM message. The following diagram identifies the data elements that are provided as part of a minimal Digital NOTAM Proposal.

Legacy - NOTAM Proposal

In this case the data originator does not have the capacity to fully digitally code necessary feature TimeSlice for the scenario and neither an Event. However, for uniformity purpose, an empty Event with the associated AIS message can be provided.

Special situations

Digital NOTAM Proposal 'With Immediate Effect"

When a NOTAM needs to be issued immediately (for example, the immediate closure of a runway due to an incident), some systems allow the NOTAM originator to use " WIE" (with immediate effect) in item B of a NOTAM proposal. The same applies for item C in case of a NOTAM cancellation proposal. The NOF that processes the proposal will replace WIE with the actual system time, when the NOTAM is issued. This avoids issuing NOTAM with effective date/time in the past or obliging the originator to use an arbitrary delay in the effective time, to allow the NOF to process the proposal.

The same principle is applied to Digital NOTAM Proposals, by using an indeterminatePosition='now' attribute to indicate WIE (with immediate effect). To facilitate the sorting by effective time in the Digital NOTAM application, the Event should still have specified values for its validTime. In addition, the indeterminatePosition='now' attribute will indicate that the validTime should be replaced with the actual system date/time, when the Event and NOTAM are released.