You may think an instrument rating is only required when the conditions are IFR, but there are times when it is needed even in VFR weather.
There are generally three reasons for circling-only minimums; 1, The final approach course alignment with the runway centerline exceeds 30°; 2, The descent gradient is greater than 400 ft/NM from the FAF to the TCH, or 3, The runway is not clearly defined on the airfield.
At some airports you may be able to reach ATC on the ground using the radio frequency listed for clearance delivery or approach control. Another option is to call clearance delivery directly on your phone. You can find the phone number for the overlying Air Route Traffic Control Center (ARTCC) listed in the Chart Supplement under in the communications section under “Clearance Delivery Phone.” You can also pick up an IFR clearance after you are airborne, providing you remain VFR until you get your clearance.
Receiver autonomous integrity monitoring (RAIM) continuously monitors and compares signals from multiple satellites to ensure GPS signal accuracy. When you fly IFR using a non-WAAS GPS as your primary navigation system you are required to do a RAIM prediction check for your route before each flight. If RAIM is predicted to be unavailable, you must use other navigation systems or delay or cancel your flight.
The WAAS system evaluates the lowest minimums available and displays the corresponding minimums in the approach mode annunciator. LNAV and LP provide lateral guidance only. LNAV/VNAV and LPV also provide an approved glide slope. LNAV+V and LP+V provide lateral guidance with an advisory glide slope.