Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Simulation of inferior mirages observed at the Halligen Sea

Open Access Open Access

Abstract

Two unusual forms of inferior mirage are observed and photographed at the Halligen Sea. With heuristic analytic functions for the temperature profiles, numerical integration of the refraction differential equation on a flat earth is performed. The simulation shows that a double inferior mirage can appear if a light wind carries hot air from above dry sandbanks in the mud flats. Horizontal stripes can appear in the mirage image if a water channel crosses the line of sight between the observer and the object.

©1999 Optical Society of America

Full Article  |  PDF Article
More Like This
Simulation of inferior mirages observed at the Halligen Sea

Eberhard Tränkle
Appl. Opt. 37(9) 1495-1505 (1998)

Noninverted images in inferior mirages

Siebren Y. van der Werf
Appl. Opt. 50(28) F12-F15 (2011)

Laboratory simulation of inferior and superior mirages

Robert G. Greenler
J. Opt. Soc. Am. A 4(3) 589-590 (1987)

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (12)

Fig. 1.
Fig. 1. Ray tracing for the pixmap hallig. Profile P2 is used.
Fig. 2.
Fig. 2. Dependence on eye position for the pixmap hallig; P1, P2, and P3 are used.
Fig. 3.
Fig. 3. Dependence on distance for the pixmap walker; P1, P2, and P3 are used.
Fig. 4.
Fig. 4. Effects of fast air fluctuations for a walker from Engler’s film; T1 is adjusted.
Fig. 5.
Fig. 5. Double inferior mirage of the Ockenswarft at the hallig Hooge. The photograph is taken from the sandbank Japsand (see Fig. 6).
Fig. 6.
Fig. 6. Map of the Halligen Sea.
Fig. 7.
Fig. 7. Ray tracing for the pixmap hallig; T2 is adjusted.
Fig. 8.
Fig. 8. Dependence on eye position for the double inferior mirage of the Ockenswarft; T2 is adjusted.
Fig. 9.
Fig. 9. Inferior mirage of the Schulwarft at the hallig Nordstrandischmoor. The photograph was taken from the Hamburger Hallig.
Fig. 10.
Fig. 10. Ray tracing for the pixmap hallig; T3 is adjusted.
Fig. 11.
Fig. 11. Dependence on eye position for an image with a stripe of a warft at the hallig Nordstrandischmoor; T3 is adjusted.
Fig. 12.
Fig. 12. Simulation of three photographs of a mirage of the hallig Südfall at high tide; T3 is adjusted.

Tables (2)

Tables Icon

Table 1. Three Sets of Parameter Values of T1, from Measured Temperature Values on a Calm Day

Tables Icon

Table 2. Parameter Values for the Temperature Profiles used for the Simulations Shown

Equations (5)

Equations on this page are rendered with MathJax. Learn more.

d z d x = ± 1 w n ( T ) 2 w 2 with
n = 1 + 0.08 273.15 + T ( z , x ) ,
T 1 ( z ) = a exp ( z b ) cz + d .
T 2 ( z ) = T 1 ( z ) + e [ 1 π arctan ( z f g ) + 0.5 ] ,
T 3 ( z , x ) = T 1 ( z ) e exp [ ( x f ) 2 2 g 2 ] ,
Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.