IRL (no GPS,DTED,FLIR etc) CCIP ranging is calculated using an ordered method AGR, Radalt or Baralt. AGR is straight forward the radar range sample is used. If AGR is not available the the MC will try Radalt or Baro ranging using input altitude and known dive angle.... obviously not as accurate as AGR.
To command AGR you must have the TDC assigned to the HUD (dot in the vv)