Office of Telecommunications OT Report 75-59

Refractivity Gradients in the Northern Hemisphere

April 1975

C.A. Samson

Abstract: 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 Northern Hemisphere. These are based on climatological data from radiosonde observations, 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 climate of each site.

Keywords: Refractivity gradients, radiosonde data

• Title Page, Table of Contents

• Chapter 1: Introduction

• Chapter 2: Source of Data

• Chapter 3: Data Presentation

• Chapter 4: Discussion

• Chapter 5: Conclusions; Chapter 6: Acknowledgment

• Chapter 7: References

• Appendix A: Calculation of Refractivity

• Appendix B: The Normal Refractivity Gradient
  
  
• Appendix C: Cumulative Distributions of the Observed Radio Refractivity Gradient in the Ground-Based 100-meter Layer, pp. 23-30
• Appendix C: pp. 31-40
• Appendix C: pp. 41-50
• Appendix C. pp. 51-60
• Appendix C: pp. 61-70
• Appendix C: pp. 71-80
• Appendix C: pp. 81-90
• Appendix C: pp. 91-100
• Appendix C: pp. 101-110
• Appendix C: pp. 111-120
  
  

• Appendix D, Errata and Supplementary Remarks for A World Atlas of Atmospheric Radio Refractivity

Disclaimer: Certain commercial equipment, components, and software are identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.