A Fast Satellite Selection Algorithm Based on NSWOA for Multi-Constellation LEO Satellite Dynamic Opportunistic Navigation  
[PERSON]  
1 Information and Navigation School, Air Force Engineering University, Xi'an 710077, China;  
[EMAIL_ADDRESS] (C.D. ); [EMAIL_ADDRESS] (L.Z.) [PERSON]  
2 School of Electronic Engineering, Xidian University, Xi'an 710071, China; cyuqiang20239163.com (Y.C. );  
[EMAIL_ADDRESS] (L.L. ); [EMAIL_ADDRESS] (K.W.) [PERSON]  
2 School of Electronic Engineering, Xidian University, Xi'an 710071, China; cyuqiang20239163.com (C.N. );  
[EMAIL_ADDRESS] (L.L. ); [EMAIL_ADDRESS] (K.W.) [PERSON]  
2 School of Electronic Engineering, Xidian University, Xi'an 710071, China; cyuqiang20239163.com (Y.C. );  
[EMAIL_ADDRESS] (L.L. ); [EMAIL_ADDRESS] (K.W.) [PERSON]  
1 Information and Navigation School, Air Force Engineering University, Xi'an 710077, China;  
[EMAIL_ADDRESS] (C.D. ); [EMAIL_ADDRESS] (L.Z.) [PERSON]  
2 School of Electronic Engineering, Xidian University, Xi'an 710071, China; cyuqiang20239163.com (Y.C. );  
[EMAIL_ADDRESS] (L.L. ); [EMAIL_ADDRESS] (K.W.) [PERSON]  
3 Science and Technology on Space Physics Laboratory, China Academy of Launch Vehicle Technology,  
Beijing 100076, China; wwemengpwu126.com (Correspondence: [EMAIL_ADDRESS]; Tel. : +86-1582497294233  
expected to be in orbit by 2027 [4], providing multiple-layered global coverage and creating favorable conditions for high-precision opportunistic navigation using multi-constellation LEO satellite signals [5; 6; 7; 8]. Constellation design advances have further improved spatial coverage and link quality. For instance, [PERSON] et al. [9] proposed a piggyback-based deployment method to enhance scalability, while [PERSON] et al. [10] developed a geometry-driven approach for optimizing inter-satellite visibility. Compared to traditional GNSS signals from Medium Earth Orbit (MEO) satellites, LEO downlink signals offer distinct advantages for Positioning, Navigation, and Timing (PNT), including enhanced frequency diversity [11; 12; 13], higher signal strength [14], and improved observation geometry [15; 16]. These features have made LEO satellites a promising resource for resilient, GNSS-independent navigation systems, particularly under jamming or spoofing conditions [17; 18; 19; 20]. LEO-based opportunistic PNT using non-cooperative signals has become a key area of research. [PERSON] et al. [21] introduced a constant-vector thrust method for improved orbit control, laying the foundation for LEO-PNT in GNSS-denied environments. By analyzing frequency shifts in non-cooperative downlink signals, several studies have demonstrated the feasibility of low-accuracy PNT via pseudorange rate estimation [22; 23; 24; 25]. Experimental results show that static platforms can achieve positioning accuracy within 5.1 m using signals from Starlink, OneWeb, Iridium NEXT, and Orbcomm satellites [26]. Complementary studies [27; 28; 29] have integrated inertial navigation with LEO Doppler measurements, confirming near-static performance on low-dynamic platforms. Theoretical simulations [28] have further explored real-time orbit estimation challenges for high-dynamic applications. Moreover, link budget sensitivity has emerged as another critical factor in satellite selection. High-order modulation schemes can degrade link margins at low elevation angles [30], increasing the risk of signal loss. To address this, [PERSON] et al. [31] proposed a telemetry-aware node selection framework, and [PERSON] et al. [32] designed a multi-layered communication architecture that improves resilience through cross-layer optimization. These developments suggest that future satellite selection strategies must account for both geometric precision and link stability in real-time applications. Despite this progress, most research remains limited to static or low-dynamic conditions. Challenges such as rapid satellite motion, unknown ephemerides, and clock offset errors still hinder real-time use on dynamic platforms like UAVs [33].