Principal Gaussian Overbound for Heavy-tailed Error Bounding

Published in IEEE Transactions on Aerospace and Electronic Systems, 2024

1) What problem is this paper solving?

Context: Heavy-tailed errors in urban GNSS ruin integrity monitoring if not properly bounded.
Core contribution: Principal Gaussian Overbound (PGO) utilizing Bimodal Gaussian Mixture Models (BGMM).
Achieved goal: A tight, safe, and convolution-preserving overbound for integrity.

2) Why is this paper important?

What changed: Urban navigation requires strict integrity, but errors are heavy-tailed.
Problem created: Single-Gaussian bounds must be hugely inflated to cover tails, destroying availability.
Why current solutions fail: They are either too loose (conservative) or lack theoretical guarantees for convolution.

3) How does this paper solve it?

Contribution 1: Proposed an conservative yet sharp non-Gaussian overbound method (PGO) and mathematically proved its overbounding property is preserved through convolution.
Contribution 2: Formalized the calculation of Protection Levels (PLs) using Fast Fourier Transforms (FFT) to significantly accelerate computation.
Key result: Reduced mean Vertical Protection Level (VPL) by over 50% compared to the two-step Gaussian method.

🎯 Takeaway: A smarter way to bound heavy tails that keeps protection levels low and integrity availability high.

Illustration of the proposed PGO overbounding method

(a) The CDF (in logarithm scale) of the proposed method (Principal Gaussian overbound), the two-step Gaussian overbound, Gaussian-Pareto overbound for Urban DGNSS errors (heavy-tailed distribution); (b) The protection level of LS solution based on the proposed method (Principal Gaussian overbound) and the two-step Gaussian overbound when integrity risk is set as 10^-9.