GOES Eclipse Schedule

GOES satellites encounter two periods during the year in which they are in Earth's shadow. During the eclipse season, as these periods are known, spacecraft must use batteries up to 72 minutes each day. Eclipses occur approximately from late February to mid-April, and from late August to mid-October.

There is a significant risk of light from the sun directly entering the scanners on GOES-16/17/18 and causing degraded products as the spacecraft enters and leaves the Earth's shadow. To minimize this risk, a special algorithm is applied to the imager products. In some instances, shifting, canceling, or truncating the frame is necessary. This is known as the "Stray Light Zone." The seasonal charts describe the GOES-East and GOES-West imager and sounder scan frames that are canceled or shifted due to the Stray Light Zone.

GOES-East (GOES-16) and GOES-West (GOES-17/18)

During eclipse season with the GOES-R satellite series, stray light contamination is visible approximately 45 minutes before and after satellite local midnight (~0500 UTC for GOES-East and ~0900 UTC for GOES-West) each day for approximately 45 days before and after the vernal and autumnal equinox, in the form of a vertical beam of light that is more intense at the end closer to the Sun. Stray light contamination is often prominent in the images of visible and near infrared bands (bands 1–6), although it can also be discerned in band 7 images. This is a normal occurrence for the ABI.

During eclipse season with the GOES-R satellite series Geostationary Lightning Mapper (GLM), solar intrusion into the lens assembly will result in localized blooming (false events) and saturation (blind regions) in the data. These effects will occur daily around the same time as the ABI effects (0500 UTC and 0900 UTC). The daily effects begin with many false events at the limb, which cover regions of varying size and location as the eclipse features move across the field of view. The false events will peak during the beginning and end of the eclipse season and the 20-second files will intermittently peak in size above 3-5 MB per file during false events, which is well above the average of ~0.3 MB per file.

The increased number of false events can cause an overflow condition in the electronics which saturates the event processing. This saturation creates blind regions in the data outside of the areas impacted by the solar intrusion. The length of these temporary outages depends on the region, and is on the order of minutes. A blooming filter is being developed to remove the event spikes, although lightning detection outages will remain in the affected regions. A data quality product is under development to notify users of impacts during future eclipse seasons.