Spike detection algorithms for Raman spectroscopy: A comparative study

Energetic charged particles from the secondary cosmic radiation may interact with Raman measuring devices, leading to local charge anomalies in the signal from the CCD detector represented as single to few samples wide spikes in the resulting Raman spectrum. If not handled properly, these spikes may lead to errors in subsequent data processing steps. There are no practical means to shield the energetic muons, thus spike removal is a common and fundamental step in Raman spectral data pre-treatment. Commercial software from Raman instrument manufacturers usually provide spike removal tools, but the algorithms are not available to users and automation or control of the corrections is impossible. Open-source tools for spike removal are also limited. Moreover, the performance of these tools is rarely validated or benchmarked. The present work is an introduction to a bigger study which aims to perform a systematic comparison of spike removal algorithms. The methodology consists of artificially introduced spikes on a spike-free spectrum. Minimum detectable spike amplitude for four different algorithms is studied by performing a scan, varying the location and amplitude of the artificial spikes. Studied algorithms are made available in RamanChada2 library.