On the Theory of the Ceiling Projector*

W. E. Knowles Middleton

doi:10.1364/JOSA.29.000340

Journal of the Optical Society of America
Vol. 29,
Issue 8,
pp. 340-349
(1939)
•https://doi.org/10.1364/JOSA.29.000340

On the Theory of the Ceiling Projector

W. E. Knowles Middleton

Not Accessible

Your library or personal account may give you access

Get PDF
Email
Share
Get Citation
Copy Citation Text
W. E. Knowles Middleton, "On the Theory of the Ceiling Projector*," J. Opt. Soc. Am. 29, 340-349 (1939)

Export Citation
- BibTex
- Endnote (RIS)
- HTML
- Plain Text
Citation alert
Save article

Abstract

The ceiling projector is a small searchlight used to measure cloud heights at night. The elementary geometry of the measurement is stated, and expressions are developed for the apparent brightness of the spot of light under various atmospheric conditions, and for the total flux density from the spot at the observing station. Some remarks on the visibility of the spot are appended.

Full Article | PDF Article

More Like This

Theory of the Double Fizeau Toothed Wheel

Herbert E. Ives
J. Opt. Soc. Am. 29(11) 472-478 (1939)

The Measurement of Light Scattered by the Upper Atmosphere from a Search-Light Beam

E. A. Johnson, R. C. Meyer, R. E. Hopkins, and W. H. Mock
J. Opt. Soc. Am. 29(12) 512-517 (1939)

Measurements on Direct and Indirect Adaptation by Means of a Binocular Method

J. F. Schouten and L. S. Ornstein
J. Opt. Soc. Am. 29(4) 168-182 (1939)

Previous Article Next Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (9)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Tables (5)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (26)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Projector Vertical (α=90°)				Projector at tan⁻¹ 3.0 (α=71°34′)

h	β	∂β/∂h Degrees/100 ft.	∂h/∂βft./°	β	∂β/∂h Degrees/100 ft.	∂h/∂βft./°

100	5°43′	5.68	18	5°54′	6.04	17
200	11°19′	5.51	18	12°06′	6.28	16
500	26°34′	4.58	22	30°58′	6.06	17
1000	45°00′	2.87	35	56°19′	3.97	25
2000	63°26′	1.14	88	80°32′	1.40	71
5000	78°41′	0.221	453	97°36′	0.225	445
10,000	84°17′	0.0567	1800	103°08′	0.0543	1840

Hft.	α=71°34′			α=90°00′

	σ_a=1.5×10⁻⁵ ft.⁻¹	σ_a=1.5×10⁻⁴ ft.⁻¹	σ_a=1.5×10⁻³ ft.⁻¹	σ_a=1.5×10⁻⁵ ft.⁻¹	σ_a=1.5×10⁻⁴ ft.⁻¹	σ_a=1.5×10⁻³ ft.⁻¹

100	7.93×10⁻²	6.81×10⁻²	1.60×10⁻²	5.45×10⁻²	4.67×10⁻²	1.05×10⁻²
200	1.85	1.60	4.52×10⁻³	2.18	1.85	3.56×10⁻³
300	1.34	1.12	2.04	1.57	1.31	2.14
400	9.04×10⁻³	7.51×10⁻³	1.17	2.02	1.65	2.24
500	5.54	4.55	5.98×10⁻⁴	1.70	1.37	1.54
750	7.06	5.51	4.49	2.92	2.23	1.50
1000	1.08×10⁻²	8.56	3.78	2.04	1.47	5.63×10⁻⁴
1500	8.40×10⁻³	5.51	7.67×10⁻⁵	1.17	7.51×10⁻³	8.65×10⁻⁵
2000	5.38	3.08	1.15	6.84×10⁻³	3.85	1.27
3000	2.57	1.12	2.82×10⁻⁷	3.18	1.38	3.37×10⁻⁶
5000	9.10×10⁻⁴	2.27×10⁻⁴	2.13×10⁻¹⁰	1.10×10⁻³	2.82×10⁻⁴	3.73×10⁻¹⁰
10,000	2.00×10⁻⁴	1.20×10⁻⁵	8.11×10⁻¹⁸	2.40×10⁻⁴	1.61×10⁻⁵	2.98×10⁻¹⁷

hft.	σ_c=0.0383 ft.⁻¹ Candle·ft.⁻²	σ_c=0.0195 ft.⁻¹ Candle·ft.⁻²	σ_c=0.00383 ft.⁻¹ Candle·ft.⁻²

100	6.81×10⁻²	3.55×10⁻²	7.70×10⁻³
200	1.60	8.71×10⁻³	1.84
300	1.12	6.38	1.42
400	7.51×10⁻³	4.51	1.06
500	4.55	2.90	7.15×10⁻⁴
750	5.51	4.06	1.18×10⁻³
1000	8.56	7.21	2.53
1500	5.51	5.36	2.82
2000	3.08	3.07	2.18
3000	1.12	1.12	1.05
5000	2.27×10⁻⁴	2.27×10⁻⁴	2.27×10⁻⁴
10,000	1.20×10⁻⁵	1.20×10⁻⁵	1.20×10⁻⁵

h ft.	α=71°34′			α=90°00′

	σ_a=1.5×10⁻⁵ ft.⁻¹	σ_a=1.5×10⁻⁴ ft.⁻¹	σ_a=1.5×10⁻³ ft.⁻¹	σ_a=1.5×10⁻⁵ ft.⁻¹	σ_a=1.5×10⁻⁴ ft.⁻¹	σ_a=1.5×10⁻³ ft.⁻¹

100	6.14×10⁻⁷	5.31×10⁻⁷	1.24×10⁻⁷	3.70×10⁻⁷	3.09×10⁻⁷	6.93×10⁻⁸
200	7.06	6.02	1.24×10⁻⁷	5.45	4.55	7.32
300	1.05×10⁻⁶	8.81	1.60	8.08	6.78	1.10×10⁻⁷
400	1.27	1.05×10⁻⁶	1.65	1.72×10⁻⁶	1.41×10⁻⁶	1.91×10⁻⁷
500	1.20	9.60×10⁻⁷	1.29	2.09	1.68	1.90
750	3.05	2.38×10⁻⁶	1.94	5.00	3.82	2.47
1000	7.13	5.25	2.50	6.78	4.90	1.88
1500	7.70	5.03	6.72×10⁻⁸	6.17	3.96	4.55×10⁻⁸
2000	5.54	3.16	1.18×10⁻⁸	4.43	2.49	8.08×10⁻⁹
3000	2.74	1.19	1.3×10⁻¹⁰	2.47	1.07	2.7×10⁻¹⁰
5000	8.65×10⁻⁷	2.15×10⁻⁷	7×10⁻¹³	9.45×10⁻⁷	2.42×10⁻⁷	3.2×10⁻¹⁴
10,000	1.97×10⁻⁷	1.19×10⁻⁸	4×10⁻²¹	2.16×10⁻⁷	1.44×10⁻⁸	9.0×10⁻²¹

θ	15°	30°	45°	60°	75°	90°	105°	120°	135°	150°	165°	180°

100F/F₀	24.1	58.5	80.9	89.9	92.2	92.6	93.0	93.6	95.3	97.5	99.4	100.0

Abstract

Cited By

Figures (9)

Tables (5)

Equations (26)

Journal of the Optical Society of America