I am working in outdoor Raman Spectroscopy and the main problem i am facing is that the noise is so high.
i am trying to find a technique or an algorithm to reduce or reject this high background noise
For something as variable as the background noise in an outdoor situation your prospects will depend on how well your hardware handles the situation. Since shot noise is proportional to the square root of the intensity, it makes sense to minimise background as much as possible so it is not boosting the shot noise no matter what fancy algorithms you through at it.
What wavelength are you using and what is the ambient light intensity expected at the wavelengths you will be collecting Raman at?
Next is design of optics to maximise rejection of stray light, so you get the optimal ratio of Raman shifted light to shot noise ratio (excluding too much stray light will start to eliminate most of your Raman signal so there will be a sweet spot somewhere.
Once stray light rejection is optimised then SSRS (shifted subtracted RS) or SERS (shifted excitation RS) is an interesting possible starting point. I'm not aware of SSRS being implmented in a hardware version other than a prototype in my old lab, but SERS has a lot of literature. SORS (shifted offset RS) probably could be combined with fancy algorithms but I can't imagine it being worthwhile. Other options like rapid switching between measurement and background modes will depend on expected stability of sampling conditions etc.
It may be due to cosmic radiation
Li S, Dai L. An improved algorithm to remove cosmic spikes in Raman spectra, please refer
for online monitoring. Appl Spectrosc. 2011 Nov;65(11):1300-6. doi:
10.1366/10-06169. PubMed PMID: 22054090.
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography
- X-ray Diffraction