AirWare On-line Reference Manual
| | Release Level | 5.4 |
| | Release Date | 2008 10 |
| Revision Level | 1.0 |
Display Colors
The display of model results over user selected background maps is
based on a set of color scheme definitions.
Two different systems are being used:
- pre-defined, static arbitrary (non-linear) color ranges,
defined for any or all combination of
- pollutant;
- aggregation period (1,8,24, 8760 (annual) hours).
- a (default) dynamic color definition.
The color are defined in a simple ASCII configuration file,
/var/www/cgi-bin/mapcolor.
Dynamic default color range
The first entry in the file consists of 21 decimal, integer RGB color definitions:
| 0 | 0 | 255 |
| 0 | 100 | 255 |
| 0 | 150 | 255 |
| ... | ... | ... |
| 255 | 100 | 0 |
| 255 | 75 | 0 |
| 255 | 50 | 0 |
| 255 | 0 | 0 |
| 150 | 0 | 0 |
The interpretation is as follows:
the range between a user-defined minimum and maximum
concentration is divided into 20 equal intervalls,
each being assigned one of the first 20 colors; this range
(in terms of minimum and maximum) can be dynamically re-defined.
Values below the minimum are invisible (transparent);
values above the maximum (open ended) are displayed in color 21.
Named, static color ranges
Separated by a blank record, any number of named color definitions follow.
Their first record consiste of a variable (pollutant ) name, and an aggregation period in hours:
would indicate ozone in ppb, hourly values, and a MIN (starting) concentration
for the first concentration range and color of 3.
This header is followed by any number of color range definitions, defined
by their upper limit value:
| 0 | 0 | 255 | 12 |
| 0 | 100 | 255 | 24 |
| 0 | 150 | 255 | 36 |
| 0 | 255 | 150 | 48 |
| ... | ... | ... | ... |
| 255 | 50 | 0 | 360 |
| 255 | 0 | 0 | 400 |
| 150 | 0 | 0 | |
The file consists of the three decimal,
integer RGB definition, values and the upper limit of the corresponding
color range (concentrations lower or equal that value, and larger than
the previous bound, are shown in the corresponding color. The first range start at the MIN
value defined in the header (concentrations below MIN are invisibble);
The last range is open ended.
Implementation strategy
Any model output display always shows one
well defined combination of pollutant and aggregation period:
the model scenario has either a single substance and
aggregation period, or selectors for several pollutants and periods.
Whenever there is color scheme defined for this combination
of pollutant and aggregation period,
this is being used automatically to render the results.
- Color definitions starting at a lower limit of 0 (and thus covering the entire model
domain and map window) are rendered transparent as the default;
- Color definitions starting with a lower limit >0 are rendered opaque as the default.
If no color scheme has been defined for a given combination,
the default (dynamic) scheme is used with an initial
default of MIN and MAX values taken a second configuration file,
/var/www/cgi-bin/colorranges
This uses the following format:
| ANY | ANY | 1 | 100 |
| POLLUTANT_NAME | PERIOD | MIN | MAX |
where the first record contains the definition of a global default,
used when the dynamic scheme is selected, but no
default definition corresponding to the current
combination of substance/aggregation period can be found.
Please note that POLLUTANT_NAME is the (internal) name of the
corresponding Descriptor
defined in the systems knowledge base.
Interactive selection and configuration
At the level of the scenario display, the color bar under the map is
used as a trigger for a color scheme selection dialog:
A pop-up window shows the current selection:
- predefined or dynamic
- lower and upper bounds,
- transparent/opaque switch.
Interactive changes:
- the user can toggle the transparent to opaque selection;
- IF the default color scheme is pre-defined (regulatory interpretation),
the user can switch to the dynamic schem and change the display bounds;
- IF the default scheme is already dynamic, the display bounds can be changed.
Any such modification will only be valid for the current session.
No interactive changes will affect the rendering of the automatically
generated forecast and nowcast imagery at the first page, multi-time step diaplys or animation.
Any long-term and permanent re-definition must be done by editing
the color configuration file.
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Development notes
The color configuartion dialog will also be available from the Details page;
however, while change at the scneario level remain effective duriung a given session, any
changes made at the details page level will, by default, only be effective at this level.
An toggle switch on the dialog can enforce thei propagation to the upper (scenario) level.
The direct interactive editing of the individual concentration range boundaries
and the corresponding RGB values is planned for future releases.
The interactive editing of the color CONFIG files is planned for future releases.
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