IntuVue RDR-4000 Weather Radar Pilot's Guide
D201002000008
Technical
Operation
Rev 1, December 2014
55
WEATHER ANALYSIS MODE: CONSTANT ELEVATION
Constant elevation mode is an analysis mode providing a constant
elevation slice throughout the entire 180-degree plan view. It is called
constant elevation because the elevation slice extracted from the
memory is corrected for the earth’s curvature. With traditional tilt angle
settings the earth curves away from the beam far from the aircraft
making it difficult to exactly measure the height of a cell. The constant
elevation view provides a plan view that represents a thin slice through
the volumetric memory of weather reflectivity data. This view is
corrected for the curvature of the earth (i.e., it is a view at a constant
MSL altitude level or constant Flight Level).
The elevation slice is selected by the ELEVN knob on the control panel.
The elevation is selectable between zero and 60,000 ft in 1,000 ft
increments. On activation of the ELEVN mode, the slice at the current
aircraft altitude (rounded to the nearest 1,000 ft) is chosen. The view
does not move up or down when the aircraft altitude changes. The pilot
can quickly measure the tops of cells without any calculations. By
varying the selected altitude until a cell just disappears, the cell height
can be directly read from the display.
