Wind turbine simulation

Radar reflectivities induced by wind turbines are a long standing problem in many radar applications. Weather and air traffic control radars are specifically affected since they are supposed to cover large areas and specific spots with wind-turbine contaminated pixels cannot be easily removed without removing critical information that is also contained in these areas.

A wealth of mitigation procedures were developed in recent years but it is still close to impossible to obtain meaningful radar data in the surroundings of wind turbines, with the consequence that authorities inhibit the construction of new wind turbine if there is a slight potential that the foreseen turbine might hamper the quality of the radar data. However, the assessment of the influence of the yet to be built wind turbines on the radar data quality is a difficult task.

Palindrome Remote Sensing has developed a tool to generate realistic radar signatures of wind turbines at arbitrary locations within the field of view of a radar. The tool is based on Palindrome’s dual-polarization target simulator technology that can be used to calibrate weather radars by comparing virtually generated radar targets against the radar measured reflectivities.

Measured Doppler RCS signature of a wind turbine.

Simulated wind turbine signature.

Within a research project funded by the Swiss Federal Office of Civil Aviation, the Swiss Federal Office of Energy, the Swiss Climate Foundation as well as Switzerland’s Innovation Agency Innosuisse, the capability of Palindrome’s target simulator was enhanced such that not only point targets but also complex time-varying Doppler-RCS patterns can be generated. Radar signatures from a wind turbine were recorded with an experimental radar system. The recorded data was used to develop a simplified parameterized model that can be implemented in the target simulator, from where the wind turbine signatures can be replayed. The artificially generated radar signature from the wind turbine is then again observed with the radar system in order to compare the real with the virtually
generated Doppler-RCS pattern.

With this new technology, artificial wind turbines with arbitrary parameters can be set-up within the field-of-view of a radar under test. It can hence be tested, if a wind turbine is disturbing the specific radar and if signal-processing based mitigation techniques are capable to clean contaminated radar pixels.

Radar measurement of simplified Doppler-RCS simulation generated with the targets.

Generating artificial wind turbine radar signatures.