Thermal signature of an Antares rocket launch

November 17th, 2018 |

GOES-16 Near-Infrared

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm, left), Near-Infrared “Cloud Particle Size” (2.24 µm, center) and Shortwave Infrared (3.9 µm, right) images [click to play animation | MP4]

An Antares rocket was launched from the NASA Wallops Flight Facility on the Eastern Shore of Virginia (Space.com article) at 0901 UTC (4:01 AM local time) on 17 November 2018. At 0902 UTC a subtle thermal signature was seen just southeast of the launch site on GOES-16 (GOES-East) Near-Infrared “Snow/Ice” (1.61 µm). Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (above). The thermal signature appeared at the center of each 0902 UTC image (where map outlines have been erased for clarity).

A corresponding thermal signature was also evident on 0902 UTC GOES-16 Low-level (7.3 µm). Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (below) — since the Water Vapor spectral bands are essentially Infrared bands, the signal was due to superheated air from the powerful First Stage rocket (which burned for 3.5 minutes after launch).

GOES-16 Low-level (7.3 µm, left). Mid-level (6.9 µm, center) and Upper-level (6.2 µm, right) Water Vapor images [click to play animation | MP4]

GOES-16 Low-level (7.3 µm, left), Mid-level (6.9 µm, center) and Upper-level (6.2 µm, right) Water Vapor images [click to play animation | MP4]

Taking a closer look with AWIPS, similar thermal signatures could be seen. Note that for the hottest pixel southeast of Wallops KWAL, the 3.9 µm Shortwave Infrared brightness temperature increased from 3.4ºC to 7.3ºC between 0857 and 0902 UTC — while the corresponding 10.3 µm “Clean” Infrared Window brightness temperature only increased from 3.7ºC to 4.0ºC.

GOES-16 Near-Infrared "Snow/Ice" (1.61 µm, left). Near-Infrared "Cloud Particle Size" (2.24 µm, center), Shortwave Infrared (3.9 µm, right) and "Clean" Infrared Window (10.3 µm) images [click to play animation | MP4]

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm, top left),. Near-Infrared “Cloud Particle Size” (2.24 µm, top right), Shortwave Infrared (3.9 µm, bottom left) and “Clean” Infrared Window (10.3 µm, bottom right) images [click to play animation | MP4]

A 4-panel comparison of Near-Infrared and Water Vapor bands is shown below. The difference between spatial resolution is quite evident: 1 km at satellite sub-point for the 1.61 µm band vs 2 km for the Water Vapor (and all other Infrared) spectral bands.

GOES-16 Near-Infrared "Snow/Ice" (1.61 µm, top left). Low-level Water Vapor (7.3 µm, top right), Mid-level Water Vapor (6.9 µm, bottom left) and Upper-level Water Vapor (6.2 µm, bottom right) images [click to play animation | MP4]

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm, top left), Low-level Water Vapor (7.3 µm, top right), Mid-level Water Vapor (6.9 µm, bottom left) and Upper-level Water Vapor (6.2 µm, bottom right) images [click to play animation | MP4]

A thermal signature was also apparent using the Split Water Vapor (6.2-7.3 µm) and Split Fire (2.24-1.61 µm) band differences.