Hydrologic research is a very demanding application of fiber-optic distributed temperature sensing (DTS) in terms of precision, accuracy and calibration. The physics behind the most frequently used DTS instruments are considered as they apply to four calibration methods for single-ended DTS installations. The new methods presented are more accurate than the instrument-calibrated data, achieving accuracies on the order of tenths of a degree root mean square error (RMSE) and mean bias. Effects of localized non-uniformities that violate the assumptions of single-ended calibration data are explored and quantified. Experimental design considerations such as selection of integration times or selection of the length of the reference sections are discussed, and the impacts of these considerations on calibrated temperatures are explored in two case studies.
References
[1]
Kersey, A.D. Optical fiber sensors for permanent downwell monitoring applications in the oil and gas industry. 2000, 400–404.
[2]
Selker, J.S.; Thévanaz, L.; Huwald, H.; Mallet, A.; Luxemburg, W.; van de Giesen, N.; Stejskal, M.; Zeman, J.; Westhoff, M.C.; Parlange, M.B. Distributed fiber-optic temperature sensing for hydrologic systems. Water Resour. Res 2006, 42, doi:10.1029/2006WR005326.
[3]
Tyler, S.W.; Selker, J.S.; Hausner, M.B.; Hatch, C.E.; Torgersen, T.; Thodal, C.E.; Schladow, S.G. Environmental temperature sensing using Raman spectra DTS fiber-optic methods. Water Resour. Res 2009, 45, doi:10.1029/2008WR007052.
[4]
Tyler, S.W.; Burak, S.A.; Mcnamara, J.P.; Lamontagne, A.; Selker, J.S.; Dozier, J. Spatially distributed temperatures at the base of two mountain snowpacks measured with fiber-optic sensors. J. Glaciol 2008, 54, 673–679, doi:10.3189/002214308786570827.
[5]
Westhoff, M.C.; Savenije, H.H.G.; Luxemburg, W.M.J.; Stelling, G.S.; van de Giesen, N.C.; Selker, J.S.; Pfister, L.; Uhlenbrook, S. A distributed stream temperature model using high resolution temperature observations. Hydrol. Earth Syst. Sci 2007, 11, 1469–1480, doi:10.5194/hess-11-1469-2007.
[6]
Selker, J.S.; van de Giesen, N.C.; Westhoff, M.; Luxemburg, W.; Parlange, M. Fiber-optics opens window on stream dynamics. Geophys. Res. Lett 2006, 33, doi:10.1029/2006GL027979.
[7]
Roth, T.R.; Westhoff, M.C.; Huwald, H.; Huff, J.A.; Rubin, J.F.; Barrenetxea, G.; Vetterli, M.; Parriaux, A.; Selker, J.S.; Parlange, M.B. Stream temperature response to three riparian vegetation scenarios by use of a distributed temperature validated model. Environ. Sci. Technol 2010, 44, 2072–2078, doi:10.1021/es902654f. 20131784
[8]
Sayde, C.; Gregory, C.; Gil-Rodriguez, M.; Tufillaro, N.; Tyler, S.W.; van de Diesen, N.C.; English, M.; Cuenca, R.; Selker, J.S. Feasibility of soil moisture monitoring with heated fiber optics. Water Resour. Res 2010, 46, doi:10.1029/2009WR007846.
[9]
Steele-Dunne, S.C.; Rutten, M.M.; Krzeminska, D.M.; Hausner, M.B.; Tyler, S.W.; Selker, J.S.; Bogaard, T.A.; van de Giesen, N.C. Feasibility of soil moisture estimation using passive distributed temperature sensing. Water Resour. Res 2010, 46, doi:10.1029/2009WR008272.
[10]
Moffett, K.B.; Tyler, S.W.; Torgersen, T.; Menon, M.; Selker, J.S.; Gorelick, S.M. Processes controlling the thermal regime of saltmarsh channel beds. Environ. Sci. Technol 2008, 42, 671–676, doi:10.1021/es071309m. 18323086
[11]
Henderson, R.D.; Day-Lewis, F.D.; Harvey, C.F. Investigation of aquifer-estuary interaction using wavelet analysis of fiber-optic temperature data. Geophys. Res. Lett 2009, 36, doi:10.1029/2008GL036926.
[12]
Freifeld, B.; Finsterle, S.; Onstott, T.C.; Toole, P.; Pratt, L.M. Ground surface temperature reconstructions: Using in situ estimates for thermal conductivity acquired with a fiber-optic distributed thermal perturbation sensor. Geophys. Res. Lett 2008, 35, doi:10.1029/2008GL034762.
[13]
Tyler, S.W.; Selker, J.S. New user facility for environmental sensing. EOS Trans. Am. Geophys. Union 2009, 90, 483, doi:10.1029/2009EO500003.
[14]
Keller, C.A.; Huwald, H.; Vollmer, M.K.; Wenger, A.; Hill, M.; Parlange, M.B.; Reinman, S. Fiber optic distributed temperature sensing for the determination of the nocturnal atmospheric boundary layer height. Atmosph. Meas. Tech 2011, 4, 143–149, doi:10.5194/amt-4-143-2011.
[15]
Farahani, M.A.; Gogolla, T. Spontaneous Raman scattering in optical fibers with modulated probe light for distributed temperature Raman remote sensing. J. Lightwave Tech 1999, 17, 1379–1391, doi:10.1109/50.779159.
[16]
Suárez, F.; Aravena, J.E.; Hausner, M.B.; Childress, A.E.; Tyler, S.W. Assessment of a vertical high-resolution distributed-temperature-sensing system in a shallow thermohaline environment. Hydrol. Earth Syst. Sci 2011, 15, 1081–1093, doi:10.5194/hess-15-1081-2011.
[17]
Smolen, J.J.; van der Spek, A. Distributed Temperature Sensing: A DTS Primer for Oil and Gas Production; Shell International Exploration and Production: The Hague, The Netherlands, 2003; pp. C3–C4.
[18]
MATLAB R2011b Product Documentation: Fminsearch. Available online: http://www.mathworks.com/help/techdoc/ref/fminsearch.html (accessed on 13 October 2011).
[19]
Lagarias, J.C.; Reeds, J.A.; Wright, M.H.; Wright, P.E. Convergence properties of the Nelder-Mead Simplex method in low dimensions. SIAM J. Optim 1998, 9, 112–147, doi:10.1137/S1052623496303470.
[20]
Suárez, F.; Childress, A.E.; Tyler, S.W. Temperature evolution of an experimental salt-gradient solar pond. J. Water Climate Change 2010, 1, 246–250, doi:10.2166/wcc.2010.101.
