The SilverSphere Radar Score
Peak Spatial announces the addition of the SilverSphere Radar Score to our suite of radar assessment tools. This
Radar Score, based on a possible 500 point total, provides at once a detailed, comprehensive, and consistent
assessment of your project’s impact on radars within range of your development. This knowledge provides a
consistent score for your project while highlighting specific turbine’s impact on radars. The scoring methodology
includes detailed
 Site geometry and development scope/size; distance, angular range, areal extent
 Radar performance impact based on turbine/tower visibility at seven altitudes against three target sizes
with respect to radars (CARSR, ARSR, ASR9/11),
 Wind turbine shadowing for three target sizes and four distances behind each turbine
Modeled after the credit score approach, each development receives a technically consistent score that
government assessment organizations can use to begin their operational assessment of impacts. While not a
guarantee of project approval, the score captures a high degree of detail about a site’s potential impact, saving you
and the government, time analyzing project details and reacting to design changes.
The value of the Radar Score to a developer and the wind industry is a consistent technical assessment of radar
impacts. This consistency provides for clean assessments of individual projects and turbines by the developer
while providing the government a method of initiating and comparing assessments and an approach to evaluating
complex, cumulative assessments over time. It’s extraordinarily important to understand that the government
evaluates operational impacts of wind developments on radars which are not assessed in SilverSphere. A very high
Radar Score does not mean that a development will be approved and a low score doesn’t mean a project will be
denied. Just like a Credit Score, other factors are assessed prior to a loan decision being made.
Score Methodology
The SilverSphere Radar Score is based on a total possible score of 500 points. A higher score indicates less impact
on the selected radar by the wind development and a lower score more impact.
The score is initially vetted by specific wind development site geometries that account for distance the radar,
number of turbines, areal extent of the development, and angular range. The geometry matters in that a
development that has fewer turbines, is more distant from the radar in question, or has a more narrow angular
range relative to the radar, will have a smaller impact footprint.
The next major driver of the radar score is the visibility of turbines to the radar and the impact that that visibility
has on the radar’s performance in terms of the radar’s ability to detect an object (Probability of Detection - Pd) and
shadowing that a wind turbine might produce for various sizes of targets behind a wind development.
Degradation of Pd - The radar assessment produces very detailed Pd degradation values for the radar performance
in the radar range bin and adjacent range bins for each turbine in a development. These calculations are produced
The SilverSphere Radar Score is a proprietary scoring methodology developed by Peak Spatial Enterprises and
provided to SilverSphere users to assess their wind energy projects
for seven different altitudes above a wind development and for three different target sizes (think small, medium,
and large reflectors/aircraft). The model calculates the degradation by
determining the Pd that a radar would have at that particular location without a
wind turbine present and comparing it to the Pd that a radar would theoretically
have that included the wind turbine “clutter”.
Figure 1 - Pd Degradation Table
Selecting the “Map” hyperlink in these tables on SilverSphere highlights the turbine – radar pair. Each line of this
table also includes the size of the range bins surrounding each turbine and their individual distance and angular
measurement with respect to the radar.
Shadowing - Shadowing is evaluated for all turbines for which the tower is visible. The blades of a turbine have
minimal impact on shadowing and, typically, shadowing is a phenomenon that affects small targets and not
medium or large targets. The model produces an estimate of Pd behind each turbine at distances of 1, 5, 10, and
15 kilometers for the three target sizes.
Figure 2 - Shadowing Values for Small Targets
False Plots – The radar model in SilverSphere also calculates and presents a user detailed rotational overlap timing
of radars and wind turbines that provide the potential for the coincidence of a leading or trailing edge (of a wind
turbine blade) flash of a high radar cross section while the radar beam is scanning over the development. The
coincidence of this occurring increases the possibility that the radar will identify the flash as a target, creating a
false plot. This is widely variable but the larger the development and the more turbines visible within a sweep of a
radar, make this a more likely event.
The SilverSphere Radar Score is a proprietary scoring methodology developed by Peak Spatial Enterprises and
provided to SilverSphere users to assess their wind energy projects
Figure 3 - False Plot Timing Values
The SilverSphere Radar Score is a proprietary scoring methodology developed by Peak Spatial Enterprises and
provided to SilverSphere users to assess their wind energy projects