Sigint aircraft cruising US/Mexico border.

The Beechcraft RC-12 Guardrail is an airborne signals intelligence (SIGINT) collection platform based on the Beechcraft King Air and Super King Air. While the US military and specifically the United States Army have numerous personnel transport variants of the King Air platforms referred to with the general C-12 designation, the RC-12 specification represents a heavily modified platform that facilitates SIGINT collection through various sensors and onboard processors.

https://en.wikipedia.org/wiki/Beechcraft_RC-12_Guardrail