We have detected an air contact with our radar.

Note that we have range and bearing information, but we have no indication of the altitude of the contact. The lack of altitude information is due to the 2D nature of the SPS-49(V)5.

Now switch off the SPS-49(V)5 and switch on the SPS-48E radar by checking the 'active' box next to the sensor entry and note that the range ring is slightly smaller than it was when the SPS-49(V)5 was active. This is because the SPS-48E radar has a shorter range, which is partly because it operates in the E/F band, which is a higher frequency than the C band. Generally speaking, lower frequencies have longer maximum detection ranges at the expense of precise positional information while higher frequencies have more precise positional information at the expense of shorter maximum detection range.

Resume time (Spacebar) and note that after a few seconds altitude information is available. This is from the SPS-48E updating the contact information.