AFIS Alert System Information

Essential information about the AFIS active fire alerting system and its capabilities.

While this application is key for active fire notification, it comes with some limitations. Please review the information below to understand how the system works and the factors that may affect alert accuracy and timing.

Application Overview

The application combines data from various satellite sources to monitor fire incidents. Subscribed users receive notifications when active fires are detected within their specified geofences. The system can identify active fires within a 3-kilometer radius of the designated geofences.

Geofences and Notifications
  • Users define their geofences (specific areas of interest) for monitoring.
  • SMS and email notifications are sent to subscribed users when active fires are detected within their specified geofences.
  • The system considers both fires within the geofence and those in proximity (within the 3-kilometer buffer).
Data Sources
VIIRS

Visible Infrared Imaging Radiometer Suite — a satellite sensor that detects thermal anomalies indicative of active fires at a finer spatial resolution.

MODIS

Moderate Resolution Imaging Spectroradiometer — a satellite sensor providing broad-area fire detection and monitoring capabilities.

Challenges and Limitations
Cloud Cover

Clouds can affect the detection of active fires, potentially leading to missed incidents. Optical sensors may struggle to penetrate thick cloud cover.

Satellite Orbit Coverage

Satellite orbits determine the coverage area. Some geofences may be outside the satellite's field of view on certain days.

Satellite Overpass Timing

Satellites don't observe geofences continuously. The timing of satellite overpasses affects data collection. In some cases, a fire may start and burn out before the next overpass.

Data Processing Lag

After satellite overpasses, data must be processed to identify active fires. This processing time can introduce latency in creating alerts and sending them.

Spatial Resolution

The spatial resolution of the VIIRS and MODIS satellite sensors determines the smallest detectable fire size. Very small fires might not be detected due to limitations in spatial resolution.

Time Information

The time used in this application is in Coordinated Universal Time (UTC). Please note the offsets needed to convert to your local time.

South Africa (SAST): UTC + 2 hours. To convert to local time, add 2 hours to the UTC time displayed.
Fire Clustering

Multiple active fires can be detected within the same area. Rather than sending notifications for each individual active fire, we spatially cluster them into a single representative fire. The SMS notification includes the location of the representative fire. However, the original fire detections are shown on the AFIS viewer.

Contact Us

Have questions, feedback, or need assistance? Get in touch with the AFIS team.

Contact Us