Vaisala IRIS - Subcatchment Definition; Scheduling CATCH Products

3. In Save As, name your CATCH product.
Vaisala recommends naming your CATCH product by the number of hours of
integration and a general descriptor of the area, perhaps even the name of the
subcatchment file.
For example, if the subcatchment file for a large river watershed is called RED_RIV and
the integration time is 2 hours, save the product under the name RED_RIV_02.
More information
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Subcatchment Definition (page 124)
5.1.2 Subcatchment Definition
Subcatchment areas are defined in a file stored in the IRIS_OVERLAY directory
(typically /usr/sigmet/config/overlay).
These are given the sux .cat and are referred to as catch files.
When IRIS starts, the start-up log shows the processing of the catch files.
In general the files contain the following information for each subcatchment:
• Subcatchment index number (an integer 1, 2, 3, ...) and name.
The name is used for display.
• The threshold (mm) of accumulation depth for the warning.
• The subcatchment points in LAT/LON coordinates.
These points must define a closed region and be in sequence about the perimeter of
the region. That is, the first point and the last point must be the same.
Subcatchments that share the same boundary must be entered as complete closed
regions, that is, the shared boundary points are the same for adjacent subcatchments.
• The location of an internal point for the labeling.
This point must be within the bounded region of the catchment.
Each catch file usually has many subcatchment regions. There can be multiple subcatchment
files for dierent applications such as:
• For dierent radars in a network.
• To specify dierent warning thresholds to account for dierent integration times.
• To cover dierent major watershed areas.
Overlapping subcatchments in a file are permitted. For example, a large watershed region
could be input as a single large catchment and the smaller tributary watersheds within it be
specified as well. IRIS allows a maximum of 20 dierent catch files to be created.
For more information, see the Overlay utility in IRIS and RDA Utilities Guide.
More information
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Configuring CATCH Products (page 122)
5.1.3
Scheduling CATCH Products
The Data Time that you specify when you schedule the product are quantized to the time
value in the product configuration for the nearest interval that ends the integration.
IRIS Product and Display User Guide M211319EN-H
124 RESTRICTED