Summary
The Range Fan Calculator Processor can be used to dynamically generate a range fan forward of an event record's point geometry. A range fan is effectively a two-dimensional feature in the shape of a wedge that can be used to represent a visual or contextual range of an event record. The processor calculates the range fan provided an event record’s point geometry, range, bearing, and arc angle value.
Examples
- The Range Fan Calculator Processor can be used to calculate and display the approximate visual range of a moving vehicle. As the vehicle is in transit, the intersection between the vehicle’s range fan (field-of-view) and an asset on the ground could be used to trigger a notification.
- The processor can be used to display the potential area-of-impact from an event such as a storm or a plume of smoke from a fire.
Usage notes
- The Range Fan Calculator Processor requires the field containing the event record's point geometry be specified. The field name or a tag applied to a field within a GeoEvent Definition can be used to identify the geometry field. Alternatively, coordinate values contained in separate X and Y fields (or longitude and latitude) can be used to identify the point geometry.
- When creating a range fan, the range, bearing, and arc angle value of the range fan must be specified. These can be specified using a constant value or by referencing the field names containing the values from the source GeoEvent Definition. The range, bearing, and arc angle values must be specified as a positive integer or double value.
- Using constants for the range, bearing, and arc angle is useful when the values are fixed or not changing. For example, if a sensor in the field is always monitoring 100 feet forward, due east, with a 160-degree field-of-view, the processor can be configured to create a fixed range fan shape for this area. The range would be defined as 100 feet, the bearing as 90 (east), and the arc angle as 160.
- Specify fields as the inputs for the range, bearing, and arc angle if the values are constantly changing. For example, when a car’s direction of travel changes, so does its bearing. Configure the processor to obtain the bearing from a field with the dynamic bearing values to ensure the range fan updates its direction.
- Similar to the Buffer Creator Processor, the Range Fan Calculator Processor also requires the well-known ID (WKID) of a spatial reference to calculate the distance of the geometry (or range fan). However, the resulting range fan is not immediately projected back into the source event record’s spatial reference as it is with the Buffer Creator Processor. Instead, the processor can be configured to reproject the range fan to an entirely different spatial reference from the source event record.
- The processor replaces the source event record geometry (point) with the range fan geometry (polygon).
Parameters
| Parameter | Description |
|---|---|
| Name | A descriptive name for the processor used for reference in GeoEvent Manager. |
| Processor | The name of the selected processor. |
| Source GeoEvent Definition | The name of the inbound event record’s GeoEvent Definition. The processor uses the source GeoEvent Definition to identify fields from the inbound event record. |
| Geometry Source | The source of the event record’s point geometry. The processor constructs the range fan forward of this point. The default is Geometry Field.
|
| Geometry Field | The name of the geometry field or the GEOMETRY tagged field from the inbound event record used to identify the point geometry. The processor uses the geometry as the point from which the range fan originates. |
| X Field (Conditional) | The name of the field that contains the X coordinate (or longitude) of the event record. The X and Y coordinates are used to construct the point. Property is shown when Geometry Source is set to Coordinate Fields and is hidden when set to Geometry Field. |
| Y Field (Conditional) | The name of the field that contains the Y coordinate (or latitude) of the event record. The X and Y coordinates are used to construct the point. Property is shown when Geometry Source is set to Coordinate Fields and is hidden when set to Geometry Field. |
| Range Source | The source of the range value. A range value is necessary to calculate the range fan. Range is the length, or distance, the range fan will be forward of the source point geometry. Range can be defined using a constant value or from dynamically updating values in a field. The default is Constant.
|
| Range | The range as a constant value using a positive integer or double value. The default is 1000.0. For example:
Remarque :The units for the Range parameter is defined in the Range Units parameter. |
| Range Field (Conditional) | The name of the field that identifies the range value. The list of fields shown is specific to the Source GeoEvent Definition. The range value in the field must be a positive integer or double value. For example:
|
| Range Units | The unit of measure for the range value. The default is Meters. Available units of measure include:
|
| Bearing Source | The source of the bearing value. A bearing value is necessary to calculate the range fan. Bearing is the direction, or heading, of the event record and is also used for the resulting range fan. Bearing can be defined using a constant value or from dynamically updating values in a field. The default is Constant.
|
| Bearing | The bearing as a constant value using a positive integer or double value between 0 to 360 (degrees measured clockwise from north). The default is 0.0 (north). For example:
|
| Bearing Field (Conditional) | The name of the field that contains the bearing value. The list of fields shown is specific to the Source GeoEvent Definition. The bearing value in the field must be a positive integer or double. For example:
|
| Arc Angle Source | The source of the arc angle value. An arc angle value is necessary to calculate the range fan. Arc angle is the measure of the central angle used to give the range fan its wedge shape. The arc angle can be defined using a constant value, or dynamically changing values from a field. The default is Constant.
|
| Arc Angle | The arc angle as a constant value using a positive integer or double value between greater than 0 to less than 360 (degrees measured clockwise from north). The default is 30.0. For example:
|
| Arc Angle Field (Conditional) | The name of the field identifying the arc angle value. The list of fields shown is specific to the Source GeoEvent Definition. The arc angle value in the field must be a positive integer or double. For example:
|
| Processing Coordinate System WKID | The well-known ID (WKID) of the spatial reference used to calculate the range (distance) of the range fan. The default is 3857. Remarque :A WKID appropriate to the area or extent of the processed event records must be selected. This ensures the distance of the range fan is not distorted during calculation. For example, if the incoming event records are in South Carolina then a suggested WKID would be 32133 to reduce distance calculation distortion for that region. |
| Output WKID | The well-known ID (WKID) of a spatial reference used to project the resulting range fan. The default is 4326. Remarque :The output WKID can be different than the source event record WKID. |
Considerations and limitations
- A range fan can only be constructed forward of a point. Other geometry types such as multipoint, polyline, polygon, and envelope are not supported.
- The Range, Bearing, and Arc Angle parameter values must all be provided as numerical values. Using north as a bearing value is not supported.
- The Arc Angle parameter value must be greater than 0 and less than 360. Specifying 0 does not provide the range fan an angle to create its wedge shape. In contrast, specifying 360 creates a circle. If a circle is required, consider using a Buffer Creator Processor instead.
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