Slitherine

quote:

ORIGINAL: Dragon029

Radar signature is measured in dBsm, which is a decibel / logarithmic scale. To convert from decibel square metres to normal square metres, you use the formula:

area in square metre = 10 ^ (dBsm / 10)

Then to convert an area in square metres back into dBsm, you use the formula (where the log is using base 10):

area in dBsm = 10 x log(area in square metres)

Due to the nature of logarithms and powers, the more negative a value is in dBsm, the smaller an area it represents.

So according to that chart (which is going to be speculation or from an incomplete simulation keep in mind), the F-117A has an average radar signature of -14dBsm in radar bands A-D, which roughly equals 0.04m^2, and a radar signature of -24dBsm in radar bands E-M, which roughly equals 0.004m^2.

The F-22 meanwhile apparently has an average radar signature in the A-D bands of -20dBsm or 0.01m^2 (4x smaller than the F-117), and an average radar signature in the E-M bands of -30dBsm or 0.001m^2 (again 4x smaller than the F-117).

rcs (m^2) | rcs (dBsm)
------------------------
1000      | 30
100       | 20
10        | 10
1         |  0
0.1       | -10
0.01      | -20
0.001     | -30