SPOT GNSS in Emergency and Location Based Services

Location Based Systems (LBS) market has emerged exponentially since early 2000 in the wake of growing need for Emergency Relief Applications. The argument of course outstanding is which device outperforms all other in diverse scenarios without failure. While many purpose built LBS are in use, SPOT satellite messenger gained attention for its reliability. This paper summates the system architecture and experimental tests results with those of competing Assisted and Global Navigation Satellite Systems (A/GNSS). Our test bed comprised of 26 test points with pre-established database of GNSS difficulty levels in diverse environments in UNSW. Parameters of interest are availability, accuracy and Time to First Fix (TTFF). Relative benchmarking proves SPOT’s higher TTFF and higher failure rate in general. While High Sensitivity GNSS and Assisted GNSS (MSBased and MS-Assisted) had higher availability, higher accuracy and lower TTFF. Altogether fewer failure scenarios, trustworthy coverage with cost effectiveness were observed for MS-Based AGNSS which is vital for LBS applications. However reliance on wired or wireless IP network potentially limits the performance in nonexistent underlying infrastructure in remote applications. SPOT demonstrated higher TTFF and failure rates in test scenario. On the contrary Assisted GNSS (MS-Based or MS-Assisted) can provide a reliable, cost effective and open source alternative to SPOT satellite messenger with better TTFF, availability and accuracy for consumer and research applications.