Radar-based ground surveillance provided by airborne platforms or based on distributed land-based installations is an essential ingredient for modern activity-based intelligence. Therefore, ground moving target indication radar detects objects within wide areas on land and sea and reports them through extracted radar plots. Often these radar plots end up in a big data problem due to the high number of involved objects and the long duration of typical surveillance missions. Also, the object trajectories reported by radar plots may be interrupted due to terrain masking and radar blindness within the Doppler notch. Multi-object tracking techniques create continuous object trajectories by considering the radar plots collected by multiple platforms together with topography and infrastructure. Higher level aggregation methods, like convoy detection, group tracking and traffic flow estimation, are additional methods of data analytics. Applied on the radar-based ground picture they contribute to the overall situation assessment and are suitable for focussing the attention of the users. Besides these detection and tracking aspects, object classification and identification is necessary to complete the situational ground picture. Radar contributes e.g. with synthetic aperture radar or high-range resolution. Finally, data fusion is used to combine the radar picture with additional data coming from other sensors or transponder systems.

Chapter Contents:

• Abstract
• 12.1 Introduction
• 12.2 Radar systems in ground surveillance
• 12.2.1 Radar platforms
• 12.2.2 Radar systems
• 12.2.2.1 Radar modes and types
• 12.2.2.2 Characteristics of GMTI radar
• 12.2.2.3 GMTI radar standard
• 12.3 Co-ordinate systems for ground surveillance
• 12.3.1 WGS 84 ellipsoid
• 12.3.2 Object co-ordinate systems - WGS 84 and ECEF
• 12.3.3 Platform-centric system - ENU
• 12.3.4 Sensor co-ordinate system - range, azimuth and Doppler
• 12.4 Environment models
• 12.4.1 Road maps
• 12.4.2 Digital elevation models
• 12.5 Tracking in ground surveillance
• 12.5.1 Filtering with GMTI measurements
• 12.5.1.1 State and measurement equation
• 12.5.1.2 Parametrisation of the unscented transformation
• 12.5.1.3 Initialization
• 12.5.1.4 Prediction
• 12.5.1.5 Assimilation
• 12.5.1.6 Unassisted tracking
• 12.5.1.7 Road-assisted tracking
• 12.6 Further topics in radar tracking
• 12.6.1 On-off road tracking
• 12.6.2 Tracking with multiple platforms
• 12.6.3 Group tracking
• 12.7 Information fusion and sensor management
• 12.7.1 Multi-sensor data fusion and sensor management
• 12.7.2 Traffic flow, areas, corridors and routes
• 12.7.3 Radar-based classification
• 12.7.4 Transponder systems
• 12.7.5 Electro-optical and IR sensors
• 12.7.6 Network-centric sources
• 12.8 Conclusion
• Acknowledgements
• Abbreviations
• References

Inspec keywords: airborne radar; search radar; transponders; object detection; synthetic aperture radar; data analysis

Other keywords: high-range resolution; radar picture; ground moving target indication; radar blindness; synthetic aperture radar; object identification; object trajectory; distributed land-based installations; group tracking; extracted radar plots; airborne platforms; transponder systems; terrain masking; traffic flow estimation; big data problem; surveillance missions; multiobject tracking; data analytics; object classification; situation assessment; level aggregation methods; object detection; situational ground picture; modern activity-based intelligence; convoy detection; Doppler notch; radar-based ground surveillance

Subjects: Radar equipment, systems and applications; Radar theory; Optical, image and video signal processing