By the contractor folks at MARC. Their Mission Statement indicates...
"MARC is North America's largest provider of specialized contract aircraft and flight crews for airborne GIS, survey and surveillence projects. MARC provides the industry a modified fleet of Navajos, Navajo Chieftains and Merlin turbine aircraft, equipped and ready for deployment. Each aircraft is configured for all GIS applications including imagery and LiDAR installations."
These are probably common, but since I've only had the decoder running since June, they're "new" to me.
These are the various payloads they operate: http://www.marcflightservices.com/sensor.html