Chemistry Reference
In-Depth Information
Fig. 1.
Marine radar system noise floor (or Minimum Detectable Signal (MDS))
and saturation level expressed in their NRCS equivalents
The relative radiometric resolution of the instrument was derived from a
detailed error analysis of (1) using theoretical estimates of the maximum
error associated with each variable. The relative radiometric resolution was
estimated for mean NRCS images obtained by averaging a variable num-
ber, N, of consecutive antenna sweeps. The derived resolution was thus
found strongly dependent on N and on the pulse length setting (which gov-
erns the number of pulses integrated per pixel). A summary of the theoreti-
cal NRCS error is given in Table 2.
Table 2.
Typical dynamic range and radiometric resolution for marine radar and
airborne/satellite systems.
Marine radar system
Airborne/Satellite
systems
Dynamic range
~ 50 dB
50 - 70 dB
Relative NRCS error (dB)
Short
Medium
Long
0.6 dB
0.8 dB
1.1 dB
0.2 dB - 1 dB
No. images averaged t 4
0.6 dB
0.6 dB
0.6 dB
No. images averaged t 24
4 Comparing performances with traditional radars
Tables 1 and 2 present typical values for the spatial, temporal and radio-
metric resolutions of marine radar, airborne and satellite radar systems.
The marine radar is found to provide a much reduced spatial coverage but
