A Tracking-Free Automatic Target Recognition (ATR) Radar Methodology for Real-Time Airspace Management in China’s Low-Altitude Economy

Abstract. China’s Low-Altitude Economy (LAE) requires robust airspace surveillance for the safe integration of Vertical Take-off and Landing (VTOL) aircraft and Unmanned Aerial Systems (UAS). Traditional radar Automatic Target Recognition (ATR) approaches—both micro-Doppler-based and tracking-based—depend on track accumulation, introducing Detection Response Times (DRT) exceeding 3–5 seconds that are incompatible with real-time low-altitude operations. This paper proposes a tracking-free ATR methodology that restructures the conventional serial “Detection–Tracking–Recognition” chain into a parallel “Integrated Detection and Recognition” (IDR) architecture. The classifier operates independently of the tracker, extracting target attributes from single-dwell echoes within one Coherent Processing Interval (CPI), achieving a DRT below 100 milliseconds—more than an order-of-magnitude improvement over existing systems. The methodology is validated through field trials using a X-band radar, demonstrating reliable identification of VTOL at ranges exceeding 12 km. We further clarify the precise definition of DRT and argue for NATO ATR hierarchy level T3 (Recognition) or above as the minimum performance standard for low-altitude radar sensors.