ARPA processes radar information much more rapidly than conventional radar but is still subject to the same limitations. ARPA data is only as accurate as the data that comes from inputs such as the gyro and speed log The modern integral ARPA combines the conventional radar data with the computer data processing systems into one unit. The main operational advantage is that both the radar and ARPA data are readily comparable. Target acquisition may be manual or automatic. However, there shall always be a facility to provide for manual acquisition and cancellation. ARPA with automatic acquisition shall have a facility to suppress acquisition in certain areas. On any range scale where acquisition is suppressed over a certain area, the area of acquisition shall be indicated on the display. The ARPA shall be able to automatically track, process, simultaneously display and continuously update the information on at least: 1. 20 targets, if automatic acquisition is provided, whether automatically or manually acquired; 2. 10 targets, if only manual acquisition is provided