Letter | Published:

An Azimuthal Method of Measuring Cloud Height with a Searchlight

Nature volume 159, pages 677678 (17 May 1947) | Download Citation



THE normal method of determining the height of the cloud base at night is to direct a vertical searchlight beam on to the cloud and measure the angle of elevation E of the spot of light from a point at a known horizontal distance L from the searchlight. The height h of the cloud base is then given by h = L tan E. The length L of the base-line is normally about 1,000 ft.

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  1. Meteorological Office, Dunstable, Beds. March 24.

    • E. G. BILHAM


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