APPENDIX D. ERRATA AND SUPPLEMENTARY REMARKS FOR "A WORLD ATLAS OF

10.

11.

ATMOSPHERIC RADIO REFRACTIVITY

C.A. Samson and B.A. Hart

In the original analysis of radiosonde data for the Atlas, no lag
corrections were used, and linear interpolation was used to obtain
the 50- and’100-m points on the soundings.
On page 13, 12th line from the bottom of the right-hand column,
“western Mediterranean Sea" should be changed to “eastern Mediter-
ranean Sea".
Add to Table 1, page 20:

Mediterranean, 4 stations, February 1.2 N-units, August 1.6

N-units, 12 month estimate 1.4 N-units, 12-month rms 0.4
In figure A-1, page 32, change station No. 64 in Mexico to
No. 63 (Mazatlan) .
The gradient data in Appendix C are based upon records of radio-
sonde observations made only once or twice daily. All references
to "percent of time" should be interpreted as "percent of the
observations".
Figures C-l through C-4 refer to positive gradients, or
sub-refractive conditions.
In figures C-5 through C-12, "Gradient exceeded" indicates that for
the given percentage of the observations the gradients were more
positive (or less negative).
On page 70, figure C-13, Coral Harbor (64-12 N, 83-22 W) was
mistakenly plotted as 9.8 on the original map; it should have been
19.7. This would alter the contour lines in that area.
Figure C-41 through C-56 refer to negative gradients, or a decrease
of refractivity with height (normal gradients to superrefractive
and ducting conditions).
In table C-1 on page 92, change the Fort Smith February median to
1019 (instead of 872) and the minimum to 464 (instead of 9).
Pages 93-116, figures C-57 through C-78: On all of these figures,
the title should read "Cumulative probability distributions of
dN/dh for ground based 50-m layer:". Note, however, that figures

C-1 through C-56 all refer to 100-m layers.

121




FORM OT-29 U.S. DEPARTMENT OF COMMERCE.
(3-73) OFFICE OF TELECOMMUNICATIONS

BIBLIOGRAPHIC DATA SHEET

T. PUBLICATION OR REPORT NO] 2. Gov't Accession No. | 3. Recipient's Accession No.
OTR 75-59
‘4. TITLE AND SUBTITLE 5. Publication Date
April 1975
Refractivity Gradients in the Northern Hemisphere 6. Performing Organization Code
OT/ITS
7. AUTHOR(S) 9. Project/Task/Work Unit No.
C.A. Samson 910 2385
8. PERFORMING ORGANIZATION NAME AND ADDRESS
U.S. Department of Commerce
office of Telecommunications 10. Contract/Grant No.
Institute for Telecommunication Sciences
325 Broadway, Boulder, Colorado 80302 P.O. ACC-408-74
11, Sponsoring Organization Name and Address 12, Type of Report and Period Covered
[Deputy Chief of Staff for Plans and Operations
U.S. Army Communications Command
[Fort Huachuca, Arizona 85613 13.

14, SUPPLEMENTARY NOTES,

15, ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant
bibliography of literature survey, mention it here.)

The continued expansion of microwave radio links and the resulting congestion
have increased the need for better performance estimates. In the evaluation of
refractivity effects, the designer may wish to consider the average gradients at
specific locations for different seasons, as well as diurnal changes. This report
presents graphs showing the cumulative probability distributions of the atmospheric
radio refractivity gradients in the ground-based 100-m layer for 87 stations in the
jorthern Hemisphere. These are based on climatological data from radiosonde
pbservations, and show the average conditions in one month of each season. A
limited number of diurnal comparisons are included, as well as information on the
limate of each site.

16. Key words (Alphabetical order, separated by semicolons)

Refractivity gradients, radiosonde data

17, AVAILABILITY STATEMENT 18. Security Class (This report) 20, Number of pages
(x) UNLIMITED. Unclassified 128
19. Security Class (This page) 21. Price:

(J) FOR OFFICIAL DISTRIBUTION.

Unclassified

USCOMM-DC 29716-P73
USCOMM - ERL