With an inoperative air speed indicator; the FO reported the ferry permit and aircraft were refused as unsafe by the Captain.

Narrative

When reviewing the logbook it was discovered that the previous crew had done an air return based on unreliable speed. A special flight permit was then issued based on ADR1 being inoperative. The logbook stated that an inspection had been done by Maintenance of the TAT1 (Total Air Temperature) prob; no defects were noted; and the aircraft was signed off to ferry the aircraft and aircraft was safe for flight. Under the other restrictions section of the special flight permit stated; follow Manual pro/abnormal and emergency procedures for ADR1 fault. Based on the logbook entry of the aircraft safe for flight; I took this statement as follow the Manual procedure if ADR1 fault to occur. Based on previous crews write-up; Captain briefed me to pay close attention to airspeed disagreement on takeoff and we both came to an agreement that we will abort if a speed discrepancy is noted. On takeoff role; me the FO; was the pilot PM; said 80 kts and Captain noted the airspeed was only at 50 kts so he performed the abort. We exited the runway and called dispatch to coordinate a gate return. While waiting for ground personnel to get in place; Captain spoke with Maintenance control about the abort and he stated we needed to preform the Manual abnormal procedure and that's what the special flight permit is for. Soon after; dispatch sent us an ACARS telling the ramp crew was ready to bring us into the gate. After arriving at the gate and talk with the captain we agreed to call Maintenance Control and verify exactly what we were to do. He confirmed to follow abnormal ADR1 procedures which after doing so; showed no airspeed; altitude; or vs on the captain side. The Captain and I both agreed that this is unsafe and therefore refused the aircraft in the interest of safety. The ferry permit guidance in the Operations Manual could be more detailed on procedures to follow. Also; this specific permit should have been more informative on what to expect and do. I feel I could have also called maintenance before departure for clarification on what is expected which would have prevented us departing in the first place. I feel this ferry permit was unsafe and should not have been issued.Ferry Permit issuance and listed procedure created an aircraft to be unsafe for departure.