Regional Jet 700 ER/LR (CRJ700)
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Situational Awareness; Confusion; Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Flight Crew Diverted
Aircraft; Environment - Non Weather Related; Human Factors
Flying an aircraft with the known Collins systems error; we received the expected FMS DR message on the ground that remained after takeoff. However; the message did not resolve; as expected; and became a DR EXCEEDS 5 MIN (yellow) message about the time we noticed the map display did not match our view out the window nor our (advisory only) own-ship display on the iPad Jepp application. We attempted to resolve the issue by referencing information in the QRH (not much guidance); cycling the AUTO mode of the navigation system; and manually selecting/tuning VOR/DMEs for position fixing. Nothing seemed to resolve our position error and we could not tune; identify; or monitor NAVAIDs in 'green needles.' As the Captain (Pilot Monitoring) reached for the mic switch to notify ATC; we received the dreaded call from Center inquiring as to where we were going. We advised of our loss of navigation capability and requested vectors to our next fix while we determined a course of action.  Discussion with Dispatch was difficult via both ACARS and AIRINC (everyone reminded us we could fly in 'green needles' with the Collins problem despite our efforts to explain that we had lost such ability). The Captain; after requesting input from me (i.e. good CRM); decided to divert to ZZZ because it was along our route and close to our current position; it had more options to accommodate passengers; and it had MX support. We received vectors for the remainder of the flight culminating with a visual approach; requesting a runway with PAPIs for vertical guidance; and landed without incident. After a long taxi; due to ZZZ ramp congestion; we parked at the gate; deplaned the passengers; and gave the jet to MX.  With a tail swap; we continued with some of the passengers to ZZZ1. Unknown MX problem caused degraded navigation capability.
CRJ First Officer reported experiencing navigation errors due to aircraft equipment malfunction.