Parameter Description
LOG Adjusted higher than usual for weather.
This is to eliminate speckles in intensity which could produce false
alarms.
Speckle remover Disabled so that single bin targets are passed. These could contain a
point airborne target.
Elevation angles Few elevation angles covering only the heights of interest to a range of
approximately 60 km (37.3 mi). This allows more rapid updates.
For example, for a 1° antenna beam, the 5 elevation angles of 0.5, 1.5,
2.5, 3.5, 4.5 would provide continuous vertical coverage up to 2 km
(1.2 mi), from 25 ... 60 km (15.5 ... 37.3 mi). At 10 km (6.2 mi) the
coverage would be to above the radar.
Scan rate Moderately fast scan rate (>3 RPM) consistent with rapid updates, but
still allowing approximately 50 pulses per antenna beam width.
For example a PRF of 1000 Hz and a scan rate of 3 RPM (18 degrees per
second) would provide 1000/18=55 pulses for each degree of antenna
motion.
Input Product Selection
Table 16 Suggested Input Product Types for Target Warning
Product Type Description
PPI
dBZ or radial velocity at single
or multiple sweeps.
Radial velocity is recommended for discriminating between airborne targets
and background clear air or weak weather echoes.
Airborne targets, such as aircraft or birds, move at a dierent velocity than
the air so that, provided the targets are stronger targets, they produce a
velocity anomaly which can be passed by the contrasting algorithm.
If the motion of the target is perpendicular to the radar beam, the clutter
filtering can remove targets so there is a possibility of some "blind" sectors
because of this.
VIL
Covering the layer of interest.
VIL is a useful product for target warning since it integrates echo over a
selected layer.
Single PPI products can be used, but since they are at only one elevation
angle, not all heights are covered. However, a PPI product made with the
wild card * in the elevation selection can be used to combine together all the
PPI products in a volume regardless of the elevation angle.
In this case, the DWELL algorithm runs at the completion of every sweep,
and since the algorithm is intensive, the system may not have enough CPU
power to do all of the DWELL products plus the other functions (for
example, user display, animation, other product generation, communication).
The DWELL product generation would then fall behind real time.
Therefore if all of the PPI products are used, it is recommended that the
DWELL product schedule entry use the Skip Time in Product Scheduler, set
to the time between volume scans. Thus a new DWELL product is produced
on the completion of the volume scan rather than on completion of each
individual PPI.
IRIS Product and Display User Guide M211319EN-H
154 RESTRICTED
To Next Page
Loading...