# Transient Interference Excision and Spectrum Reconstruction with Partial Samples Using Modified Alternating Direction Method of Multipliers-Net for the Over-the-Horizon Radar

## TL;DR

This paper introduces a new method to improve radar signal processing by removing interference and reconstructing sparse radar data for better target detection.

## Contribution

The novel contribution is a modified ADMM-Net for efficient and accurate spectrum reconstruction of sparse OTHR signals.

## Key findings

- Transient interference is effectively identified and removed using sparse basis representation.
- The modified ADMM-Net successfully reconstructs the Doppler spectrum for improved target detection.
- Simulation and real data validate the method's superior performance over traditional approaches.

## Abstract

Transient interference often submerges the actual targets when employing over-the-horizon radar (OTHR) to detect targets. In addition, modern OTHR needs to carry out multi-target detection from sea to air, resulting in the sparse sampling of echo data. The sparse OTHR signal will raise serious grating lobes using conventional methods and thus degrade target detection performance. This article proposes a modified Alternating Direction Method of Multipliers (ADMM)-Net to reconstruct the target and clutter spectrum of sparse OTHR signals so that target detection can be performed normally. Firstly, transient interferences are identified based on the sparse basis representation and then excised. Therefore, the processed signal can be seen as a sparse OTHR signal. By solving the Doppler sparsity-constrained optimization with the trained network, the complete Doppler spectrum is reconstructed effectively for target detection. Compared with traditional sparse solution methods, the presented approach can balance the efficiency and accuracy of OTHR signal spectrum reconstruction. Both simulation and real-measured OTHR data proved the proposed approach’s performance.