# An efficient smoothing algorithm for range external guidance data based on dynamic threshold and adaptive interpolation

## TL;DR

This paper introduces a real-time data smoothing method for photoelectric theodolites using dynamic thresholds and adaptive interpolation to improve image stability.

## Contribution

A novel field processing method combining dynamic thresholding and adaptive interpolation for real-time outlier detection and smoothing of external guidance data.

## Key findings

- The dynamic threshold method achieves over 80% outlier detection with low false alarms.
- The interpolation algorithm effectively handles both stuck and non-stuck data, producing smooth results.
- The method has been successfully applied in trajectory measurement systems.

## Abstract

To achieve real-time smoothing of external guidance data for photoelectric theodolites and ensure stable image acquisition, this paper proposes a field processing method based on dynamic thresholding and adaptive interpolation. First, to address outliers in the external guidance data, a method for dynamically calculating sample variance using an influence function is introduced. This approach establishes an adaptive threshold for real-time outlier detection in real time. Second, for the interpolation of external guidance data, the coherence of the interpolation calculations is evaluated, and the “stuck” external guidance data is categorized. Different strategies are applied based on the severity of the stuck condition, enabling real-time smooth interpolation. Experimental results demonstrate that the proposed dynamic threshold-based five-point extrapolation outlier elimination method achieves an average outlier detection rate of over 80% with a very low false alarm rate. The interpolation algorithm effectively handles both stuck and non-stuck external guidance data, producing smooth and coherent processing results. This method has demonstrated significant results in practical application, meeting the requirements of the trajectory measurement system.