Colorado State University - CHicago ILLinois radar, colloquially CSU-CHILL, is a semi-mobile, dual-frequency weather surveillance radar developed in 1970 by the University of Chicago[1] and the Illinois State Water Survey,[2] which has since been moved to Colorado on behalf of Colorado State University.

[3] The radar was operated through a cooperative agreement with the National Science Foundation.

[4] CSU-CHILL is used to study atmospheric principles and precipitation on a small scale with the use of two frequencies.

Each transmitter can individually transmit its respective frequency through its own feed horn onto the 9m offset parabolic antenna.

[6] It is often positioned near Greeley, Colorado, but is semi-mobile, so that it is movable in separate pieces, and can be quickly assembled or disassembled to participate in a field study.