American Journal of Remote Sensing
Volume 3, Issue 1, February 2015, Pages: 1-5
Received: Feb. 27, 2015;
Accepted: Mar. 17, 2015;
Published: Mar. 24, 2015
Views 3328 Downloads 280
Sandra Sadate, Department of Physics, Chemistry and Mathematics, Alabama A&M University, U.S.A.
Carlton Farley III, Department of Physics, Chemistry and Mathematics, Alabama A&M University, U.S.A.
Aschalew Kassu, Department of Engineering, Construction Management and Industrial Technology, Alabama A&M University, U.S.A.
Anup Sharma, Department of Physics, Chemistry and Mathematics, Alabama A&M University, U.S.A.
We have demonstrated that standoff Raman spectra of some nitrates could be obtained at distances ranging from 20 meters to 250 meters using an 11-inch reflecting telescope and a continuous wavelength 785 nm laser of 400 mW power coupled with a small portable spectrometer. The measurements were taken during both day and night, indoors and outdoors, for various integration times. Detection and identification of chemical and biological hazards within the forensic and homeland security contexts requires conducting the analysis in field while adapting a non-contact approach to the hazard. In this paper, we report the adequacy of a standoff Raman system with a 785nm laser for remote detection and identification of ammonium, sodium, and magnesium nitrates in bulk form. The results demonstrate that, as the standoff distances increases, there is a discernible attenuation in the intensity of the Raman signatures of the nitrates. To discriminate the background lights, improve the signal-to-noise ratio and trigger the weak characteristic bands, Raman spectra were also acquired using higher integration time. For the measurements taken at a 100 meter standoff distances, we were able to achieve a signal-to-noise ratio of about 10. For greater distances, due to the difficulty of locating the target using IR laser, a 50 mW green laser pointer at 485 nm wavelength is used before the IR laser is used for acquiring the Raman signals.
Carlton Farley III,
Standoff Raman Spectroscopy of Explosive Nitrates Using 785 nm Laser, American Journal of Remote Sensing.
Vol. 3, No. 1,
2015, pp. 1-5.
S. M. Angel, T. J. Kulp and T. M. Vess, “Remote-Raman spectroscopy at intermediate ranges using low-power CW lasers,”Appl. Spect., vol. 46, no. 7, pp.1085-1091, 1992.
S. K. Sharma, S. M. Angel, M. Ghosh, H. W. Hubble and P. G. Lucey, “Remote pulsed laser Raman spectroscopy system for mineral analysis on planetary surfaces to 66 meters,” Appl. Spect., vol. 56, no. 6, pp. 699-705, 2002.
S. K. Sharma, P. G. Lucey, M. Ghosh, H. W. Hubble and K. A. Horton, “Stand-off Raman spectroscopic detection of minerals on planetary surfaces,”Spectrochimica Acta Part A, vol. 59, pp.2391-2407, 2003.
J. C. Carter, S. M. Angel, M. L. Snyder, J.Scaffidi, R. E. Whipple and J. G. Reynolds, “Standoff detection of high explosive materials at 50 meters in ambient light conditions using a small Raman instrument,”Appl. Spect., vol. 59, no. 6, pp.769-775, 2005.
J. C. Carter, J. Scaffidi, S. Burnett, B. Vasser, S. K. Sharma and S. M. Angel, “Stand-off Raman detection using dispersive and tunable filter based systems,” Spectrochimica Acta Part A, vol. 61, pp. 2288-2298, 2005.
S. K. Sharma, A. K. Misra, P. G. Lucey, S. M. Angel and C. P. McKay, “Remote pulsed Raman spectroscopy of inorganic and organic materials to a radial distance of 100 meters,”Appl. Spect., vol. 60, no. 8, pp.871-876, 2006.
S. K. Sharma, A. K. Misra and P. G. Lucey, “Remote Raman spectroscopic detection of minerals and organics under illuminated conditions from a distance of 10 m using a single 532 nm laser pulse,”Appl. Spect., vol. 60, no. 2, pp.223-228, 2006.
E. L. Izake, “Forensic and homeland security applications of modern portable Raman spectroscopy,” Forensic Science International, vol. 202, pp. 1-8, 2010.
A. Pettersson, I. Johansson, S. Wallin, M. Nordberg and H. Ostmark, “Near real time standoff detection of explosives in a realistic outdoor environment at 55m distance,” Propellants Explo.Pyrotech., vol. 34, pp.297-306, 2009.
A. Pettersson, S. Wallin, H. Östmark, A. Ehlerding, I. Johansson, M. Nordberg, H. Ellis and A. Al-Khalili, “Explosives standoff detection using Raman spectroscopy: From bulk towards trace detection,” Proc. of SPIE, vol.7664, pp.76641K, 2010.
S. Wallin, A. Pettersson, H. Östmarkand A. Hobro, “Laser-based standoff detection of explosives: a critical review,” Anal. Bioanal. Chem., vol. 395, pp.259-274 2009.
I. Johansson, S. Wallin, M. Nordberg, A. Pettersson, A.Ehlerding and H. Östmark, “Standoff forensic analysis of explosives,”42nd International Annual Conference of ICT, 2011.
P. J. Hendra, C. Jones and G. Warnes, “Fourier Transform Raman Spectroscopy: Instrumentation and Chemical Applications,” Ellis Horwood, Prentice Hall, New Jersey, 1991.
D. B. Chase and J. F. Rabolt, “Fourier Transform Raman Spectroscopy: From Concept to Experiment,” Academic Press, San Diego, 1994.
M. J. Pelletier, “Analytical Applications of Raman Spectroscopy, Blackwell Science,” Oxford, 1999.
I. R. Lewis and H. G. Edwards, “Handbook of Raman Spectroscopy,” Marcel Dekker, New York, 2001.
J. M. Chalmers and P. R. Griffiths, “Handbook of Vibrational Spectroscopy,” John Willey and Sons Ltd., New Jersey, 2002.
J. M. Chalmers, G. M. Edwards and M. D. Hargreaves, “Infrared and Raman Spectroscopy in Forensic Science,” John Wiley & Sons Ltd., New Jersey, 2012.
M. D. Hargreaves, K. Page K., T. Munshi, R. Tomsett, G. Lynch and H. G. M. Edwards, “Analysis of seized drugs using portable Raman spectroscopy in an airport environment a proof of principle study,” J. Raman Spectrosc., vol. 39, no. 7, pp. 873-880, 2008.
P. Vandenabeele, H. G. M. Edwards and J. Jehlička , “The role of mobile instrumentation in novel applications of Raman spectroscopy: archaeometry, geosciences, and forensics,” Chem. Soc. Rev., vol. 43, pp.2628-2649, 2014.
P. Vítek, J. Jehlička, H. G. M. Edwards, G. M. Howell, "Practical Considerations for the Field Application of Miniaturized Portable Raman Instrumentation for the Identification of Minerals," Applied Spectroscopy, vol. 67, Issue 7, pp. 767-778, 2013.
Adam Culka, Filip Košek, Petr Drahota, Jan Jehlicˇka, "Use of miniaturized Raman spectrometer for detection of sulfates of different hydration states - Significance for Mars studies,” Icarus, vol. 243, pp.440-453, 2014.
D. L. Rousseau, R. E. Miller and G. E. Leroi, “Raman spectrum of crystalline sodium nitrate,” J. Chem. Phys., vol48, no. 8, pp.3409- 3413, 1968.
G. Ahlijan and E. F. Mooney, “The attenuated total reflection spectra of polyatomic inorganic anions-II: The nitrogen containing anions,” Spectrochemica Acta, Part A: Molecular Spectroscopy, vol.25, no. 3, pp. 619-627, 1969.
D. E. Irish and A. R. Davis, “Interactions in aqueous alkali metal nitrates solutions,” Canadian J. of Chemistry, vol. 46, no. 6, pp. 943- 951, 1968.