End-to-End Models for Effects of System Noise on LIMS Analysis of Igneous Rocks
Description/Abstract
The ChemCam instrument on the Mars Science Laboratory will be the first extraterrestial deployment of laser-induced breakdown spectroscopy (UBS) for remote geochemical analysis. LIBS instruments are also being proposed for future NASA missions. In quantitative LIBS applications using multivariate analysis techniques, it is essential to understand the effects of key instrument parameters and their variability on the elemental predictions. Baseline experiments were run on a laboratory instrument in conditions reproducing ChemCam performance on Mars. These experiments employed Nd:YAG laser producing 17 mJ/pulse on target and an with a 200 {micro}m FWHM spot size on the surface of a sample. The emission is collected by a telescope, imaged on a fiber optic and then interfaced to a demultiplexer capable of >40% transmission into each spectrometer. We report here on an integrated end-to-end system performance model that simulates the effects of output signal degradation that might result from the input signal chain and the impact on multivariate model predictions. There are two approaches to modifying signal to noise (SNR): degrade the signal and/or increase the noise. Ishibashi used a much smaller data set to show that the addition of noise had significant impact while degradation of spectral resolution had much less impact on accuracy and precision. Here, we specifically focus on aspects of remote LIBS instrument performance as they relate to various types of signal degradation. To assess the sensitivity of LIBS analysis to signal-to-noise ratio (SNR) and spectral resolution, the signal in each spectrum from a suite of 50 laboratory spectra of igneous rocks was variably degraded by increasing the peak widths (simulating misalignment) and decreasing the spectral amplitude (simulating decreases in SNR).
| Creator/Author: | Clegg, Samuel M [Los Alamos National Laboratory] ; Bender, Steven [Los Alamos National Laboratory] ; Wiens, R. C. [Los Alamos National Laboratory] ; Carmosino, Marco L [MT. HOLYOKE COLLEGE] ; Speicher, Elly A [MT. HOLYOKE COLLEGE] ; Dyar, M. D. [MT. HOLYOKE COLLEGE] |
|---|---|
| Publication Date: | 2010 Dec 23 |
| OSTI Identifier: | OSTI ID: 1044915 |
| Report Number(s): | LA-UR-10-08458; LA-UR-10-8458 |
| DOE Contract Number: | AC52-06NA25396 |
| Other Number(s): | TRN: US201214%%580 |
| Resource Type: | Conference |
| Resource Relation: | Conference: 42nd Lunar and Planetary Science Conference ; March 7, 2011 ; The Woodlands, TX |
| Research Org: | Los Alamos National Laboratory (LANL) |
| Sponsoring Org: | DOE |
| Subject: | 47 OTHER INSTRUMENTATION; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACCURACY; AMPLITUDES; BREAKDOWN; FIBER OPTICS; IGNEOUS ROCKS; LASERS; MULTIVARIATE ANALYSIS; NASA; PERFORMANCE; RESOLUTION; SENSITIVITY; SIGNAL-TO-NOISE RATIO; SPECTRA; SPECTROSCOPY; TARGETS |
| Country of Publication: | United States |
| Language: | English |
| Update Date: | 2012 Dec 05 |
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