When sourcing GPS technology, you must prioritize multi-constellation support, ensuring compatibility with QZSS (Quasi-Zenith Satellite System), which is specific to Japan, alongside GPS, GLONASS, and Galileo. Key performance metrics include a Cold Start Time to First Fix (TTFF) of <30 seconds and positioning accuracy within 1.5 to 2.5 meters. For industrial applications, verify the IP67 or IP68 waterproof rating and operating temperature ranges between -40°C to +85°C to ensure hardware stability.