A group of Defense Department organizations and U.S. universities has tested various aircraft in an environment where global positioning system signal is degraded.

The U.S. Air Force said Wednesday the week-long demonstration dubbed Developmental Test Navigation Festival was carried out in Edwards Air Force Base, California to evaluate aerial system performance in a GPS-denied area.

DT NAVFEST involved the 412th Test Wing’s Emerging Technologies Combined Test Force; the 411th, 416th, 419th and 461st Flight Test Squadrons; the U.S. Army‘s Special Operations Command; Stanford University; and the University of Illinois.

James Cook, KC-46A project manager at the 418th Flight Test Squadron, said the test sought to “provide a locally, more realistic GPS jamming environment in which aircraft platforms and [remotely piloted aircraft] could evaluate their performance under a degraded GPS signal.”

Cook added that other locations across U.S. provide GPS-denied environments, but the availability of such setup in Edwards AFB will eliminate the need to deploy aerial systems to other sites.

Wei Lee, a test safety engineer at the 412th Test Wing, said DoD needs to support academic institutions’ research and development efforts since it is “extremely difficult” for academic laboratories to work with the Federal Aviation Administration and first responders to obtain live GPS jamming data.

Universities were called to join DT NAVFEST on a trial basis and the Air Force aims to extend the opportunity to other institutions, Lee added.

Defense Secretary James Mattis has said a three-month continuing resolution would impact several construction and procurement programs that would affect U.S. military readiness if enacted for fiscal year 2018, Defense News reported Tuesday.

Mattis wrote in a Friday letter to Senate Armed Services Committee Chairman John McCain (R-Arizona) a short-term CR would affect readiness and maintenance operations at several service branches.

Operating at current spending levels would force the U.S. Navy to delay the induction of 11 ships, a move that would aggravate ship maintenance efforts in FY 2018 and push back ship availabilities into FY 2019.

Some of the ships that are likely to be delayed include the USS Kidd (DDG-100) Arleigh Burke-class destroyer, USS Coronado (LCS-4) Independence-class littoral combat ship and the USS Port Royal (CG-73) Ticonderoga-class guided missile cruiser.

Mattis, an inductee into Executive Mosaic‘s Wash100 for 2017, noted that a three-month CR would also impact DoD’s contracting efforts in FY 2018, including 18 new starts and eight production rate increases at the U.S. Army.

The Army’s new starts include the Armored Multi-purpose Vehicle, Paladin Integration Management Improvement program and the lightweight 30mm cannon.

A six-month CR would delay the Navy’s seven procurement contracts and affect the U.S. Air Force’s six new starts that include the Joint Space Operations Center Mission System and updates to F-15C and F-16 fighter jets, he added.

Mattis also cited the resolution’s potential impacts on personnel and training efforts across military branches and defense agencies.

Two Republican senators from Georgia have proposed an amendment to the National Defense Authorization Act for fiscal 2018 that seeks to prevent the potential retirement of the Joint Surveillance Target Attack Radar System by the U.S. Air Force, Atlanta Business Chronicle reported Tuesday.

The amendment introduced Tuesday by Sens. Johnny Isakson and David Perdue also aims to ensure the maintenance of the JSTARS aircraft fleet at Robins Air Force Base in Georgia.

The measure came days after Isakson, Perdue and three House lawmakers wrote a letter to Defense Secretary James Mattis about the service branch’s move to explore “alternative and surveillance platforms” instead of pursuing the E-8C JSTARS recapitalization program.

“There is no alternative for JSTARS and indicators of its retirement are unacceptable,” they wrote.

“Without this capability, we greatly diminish our nation’s airpower and reduce our combat strength.”

The senators co-wrote the letter with Reps. Austin Scott (R-Georgia), Sanford Bishop (D-Georgia) and Tom Graves (R-Georgia).