Notam Time Filtering
Notamify implements a sophisticated time-based filtering system for NOTAMs. This document explains how the temporal filtering logic works, how the active NOTAM endpoint funct
Last updated
Notamify implements a sophisticated time-based filtering system for NOTAMs. This document explains how the temporal filtering logic works, how the active NOTAM endpoint funct
Last updated
The active NOTAM endpoint (/api/v2/notams) is designed to always return currently active NOTAMs. This endpoint applies the time-based filtering described above to ensure that only relevant NOTAMs are returned. The system checks if:
The NOTAM overlaps with the query period
The NOTAM starts during the query period
The NOTAM spans the entire query period
The NOTAM is contained within the query period
Additionally, the endpoint includes special handling for:
NOTAMs with estimated end times that start before the query period ends
Permanent NOTAMs that start before the query period ends
This ensures complete coverage of all potentially relevant NOTAMs.
An important distinction in Notamify's filtering approach is that the "Schedule" information (found in section D of NOTAMs) is not used in the main time-based filtering logic described above.
Main Filtering: The initial filtering is based solely on the NOTAM's overall validity period (starts_at / ends_at)
Post-Filtering (client side): Schedule information can be optionally used for secondary filtering after the main time-based filtering has been applied. The schedules filed contain standardised definition, which together with duration_hrs can be used for creating the applicability ranges.
When implementing client-side applications that consume Notamify data, developers should be aware that the active NOTAM endpoint returns NOTAMs based on their overall validity period. If schedule-specific filtering is required (e.g., to check if a NOTAM is active during specific hours of operation), this should be implemented as a secondary filtering step.