On Path Weather Vs. Off Path Weather - Honeywell IntuVue RDR-7000 Pilot's Manual

IntuVueRDR-7000 Weather Radar Pilot's Guide

ON PATH WEATHER VS. OFF PATH WEATHER

The WXALLorWX PATH modesare used for the strategic detection of
weather. This fully automatic weather detection is enabled by the 3D
volumetric memory. In these modes, OnPath weather, or weather
near the altitude of the intended flight path, is displayed as distinct
from Off Pathweather, which is further removed in altitude from the
flight path. The result is a presentation of weather information that is
intuitive, improves awareness of the entire weather situation, and
reduces the potential for misinterpretations, thus reducing crew
workload.
The separation of On Path from Off Path weather is based on several
parameters:

Aircraft altitude

Flight phase (climb, level flight or descent)

Flight path (if available, or slope of aircraft climb or descent if not)

Presence of convective weather.
The separation is done by applying an envelope around the intended
flight path: weather within the envelope is considered On Path
weather, weather outside the envelope is Off Path weather. On the
display, Off Pathweather is distinguished from On Pathweather by
black stripes(see illustration on page40). If a flight plan is available, it
is used in the envelope calculation. Otherwise, the flight path angle is
computed based on the ratio of calculated vertical speed to ground
speed. In this case, the expected flight path altitude is extrapolated to
60 nm. Beyond 60 nm, level flight at the calculated altitude is
assumed.
D201911000094
Rev 0, Feb 2020
RDR-7000 Technical Operation
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