Improving runway visual range calculation using an optimized optical parameter

نوع مقاله : مقاله پژوهشی‌

نویسندگان

1 M.Sc. Graduate, Institute of Geophysics, University of Tehran, Tehran, Iran, Technical expert of meteorological organization, Tehran, Iran

2 Associate Professor, Department of Space Physics, Institute of Geophysics, University of Tehran, Iran

چکیده

Visibility deterioration may have negative impacts on aviation safety, particularly in landing and take-off procedures. Beside traditional weather observation methods which are based on human visual estimations, automatic weather observation systems (AWOS) are recently used in airports in order to provide instant measurements of the relevant meteorological parameters. One of the most important sensors is the RVR sensor. In this study, the variability of human visibility and optical instrumental visibility, including the meteorological optical range (MOR) and runway visual range (RVR), along with the probable differences between their values are investigated from December 2019 to February 2020 at Payam Airport, Karaj, Iran.
    Results indicate that in different weather conditions, the values of MOR and RVR are predominantly greater than human visibility. In this investigation, MOR is about 99% and 96% more than observed visibility for daytime and nighttime, respectively. The probable reasons for such discrepancies between these two sources of data have argued in this paper. However, to overcome the differences between the two methods, an optimized parameter is introduced as visual optical range (VOR). This parameter simulates human’s visibility through MOR to gain the benefits of both methods. Using darkness coefficient, the new parameter depends not only on extinction coefficient but also on sky brightness. The value of 0.07 is proposed for VOR calculation instead of 0.05 in the calculation of MOR. Meanwhile, in the new method, RVR value is also taking the greater values of the Allard’s visibility and VOR rather than MOR. Applying this method, it is observed that VOR values align between traditional and instrumental visual ranges. Furthermore, the new method gives more reasonable results considering minimum values of the runway’s light intensity over nighttime.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Improving runway visual range calculation using an optimized optical parameter

نویسندگان [English]

  • Yashar Rostami 1
  • Farhang Ahmadi-Givi 2
  • Samaneh Sabetghadam 2
1 M.Sc. Graduate, Institute of Geophysics, University of Tehran, Tehran, Iran, Technical expert of meteorological organization, Tehran, Iran
2 Associate Professor, Department of Space Physics, Institute of Geophysics, University of Tehran, Iran
چکیده [English]

Visibility deterioration may have negative impacts on aviation safety, particularly in landing and take-off procedures. Beside traditional weather observation methods which are based on human visual estimations, automatic weather observation systems (AWOS) are recently used in airports in order to provide instant measurements of the relevant meteorological parameters. One of the most important sensors is the RVR sensor. In this study, the variability of human visibility and optical instrumental visibility, including the meteorological optical range (MOR) and runway visual range (RVR), along with the probable differences between their values are investigated from December 2019 to February 2020 at Payam Airport, Karaj, Iran.
    Results indicate that in different weather conditions, the values of MOR and RVR are predominantly greater than human visibility. In this investigation, MOR is about 99% and 96% more than observed visibility for daytime and nighttime, respectively. The probable reasons for such discrepancies between these two sources of data have argued in this paper. However, to overcome the differences between the two methods, an optimized parameter is introduced as visual optical range (VOR). This parameter simulates human’s visibility through MOR to gain the benefits of both methods. Using darkness coefficient, the new parameter depends not only on extinction coefficient but also on sky brightness. The value of 0.07 is proposed for VOR calculation instead of 0.05 in the calculation of MOR. Meanwhile, in the new method, RVR value is also taking the greater values of the Allard’s visibility and VOR rather than MOR. Applying this method, it is observed that VOR values align between traditional and instrumental visual ranges. Furthermore, the new method gives more reasonable results considering minimum values of the runway’s light intensity over nighttime.

کلیدواژه‌ها [English]

  • Visibility
  • meteorological optical range (MOR)
  • runway visual range (RVR)
  • Koschmieder’s law
  • Allard’s visibility
  • visual optical range (VOR)

مراجع

Biral, 2010, Operation and Maintenance Manual for the VPF-730. Combined Present Weather Sensor & VPF-710 Visibility Sensor: Biral, 79 pp.
Cornick, J. C., 1993, A comparison of ceiling and visibility observation for NWS manned observation sites and ASOS sites: Colorado State University, Report, 71 pp.
Douglas, C. A., and Booker, R. L., 1977, Visual Range: Concepts, Instrumental Determination, and Aviation Applications: US Department of Commerce, National Bureau of Standards, 373 pp.
Duntley, S. Q., 1948, The visibility of distant objects: Journal of the Optical Society of America, 38, 237–249.
Horvath, H., 1981, Atmospheric visibility: Atmospheric Environment, 15, 1785-1796.
ICAO, 2004, Meteorological Service for International Air Navigation, Manual, Annex 3, 148 pp.
ICAO, 2005, Manual of Runway Visual Range Observing and Reporting Practices, Doc 9328, third edition, 105 pp.
Jenamani, R., and Tyagi, A., 2011, Monitoring fog at IGI airport and analysis of its runway-wise spatio-temporal variations using Meso-RVR network: Current Science, 100(4), 491-501.
Kim, K. W., 2018, The comparison of visibility measurement between image-based visual range, human eye-based visual range, and meteorological optical range: Atmospheric Environment, 190, 74-86.
Koschmieder, H., 1924, Theorie der horizontalen sichtweite: Beiträge zur Physik der freien Atmosphäre: Meteorologische Zeitschrift, 12, 33–55.
Lee, Z., and Shang, S., 2016, Visibility: How applicable is the century-old Koschmieder model?: Journal of the Atmospheric Sciences, 73, 4573-4581.
Liou, K. N., 2002, An introduction to atmospheric radiation, 84: Elsevier.
Malm, W., 1999, Introduction to Visibility: Colorado State University, 79 pp.
Matsuzawa, M., and Takechi, H., 2012, Evaluating the degree of visibility deterioration perceived by drivers during snowstorms: SIRWEC, Helsinki, ID 37, 23-25 May 2012.
Meteo France, 2020, Visibility for Aeronautical Purposes: Report, 33 pp.
Middleton, W. E. K., 1947, Visibility in Meteorology: The Theory and Practice of the Measurement of the Visual Range: University of Toronto Press, 165 pp.
Middleton, W., 1952, Vision through the Atmosphere: University of Toronto Press.
Sabetghadam, S., Ahmadi-Givi, F., and Golestani, Y., 2014, Application of a digital image processing method for determination of atmospheric extinction coefficient for the city of Tehran: Geophysics, 9(2), 40-51.
Stuke, S., 2016, Characterizing Thin Clouds Using Aerosol Optical Depth Information: University of Innsbruck.
Vaisala, 2011, Transmissometer Sensor LT31: Vaisala Manual, 292 pp.
WMO, 1990, The First WMO Intercomparison of Visibility Measurements: Report, 153 pp.
WMO, 2008, Guide to Meteorological Instruments and Methods of Observation: Guide 8, 681 pp.
Zege, E. P., Ivanov, A. P., and Katsev, I. L., 1991, Image Transfer through a Scattering Medium: Springer-Verlag.
مجله ژئوفیزیک ایران
دوره 17، شماره 3
مهر و آبان 1402
صفحه 77-89

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