# Accession Number:

## AD0654707

# Title:

## A NOTE ON THE POLARIZATION AND PHASE CHARACTERISTICS OF RADIO WAVES PROPAGATING THROUGH THE LOWER IONOSPHERE.

# Descriptive Note:

## Final rept.,

# Corporate Author:

## NAVAL RESEARCH LAB WASHINGTON D C

# Personal Author(s):

# Report Date:

## 1967-06-05

# Pagination or Media Count:

## 44.0

# Abstract:

Some ionospheric radio propagation problems associated with the satellite radar situation have been examined for radar frequencies between 100 and 1000 Mcs. It has been shown that the maximum number of fades exhibited by a train of radar pulses is governed by the quantity H csc I, where H is the magnetic field intensity and I is the magnetic field inclination, except near the magnetic equator. At 100 Mcs the maximum number of fades is characteristically less than 50, and since the Faraday rotation is inversely proportional to the square of the radar frequency, only one-half of a fade should be observed at 1000 Mcs. Faraday rotational signal degradation of a linearly polarized radar signal has been shown to be negligible at 1000 Mcs except possibly during winter days at sunspot maximum. In all but possibly the polar region, it is suggested that the relationship between irregularity scale Delta L and phase excursion Delta delta is given by Delta LDelta delta n sub f approximately equal to 1000, where Delta L is in meters, Delta delta is in radians, and n sub f is the radar frequency in hundreds of megacycles per second. Author

# Descriptors:

# Subject Categories:

- Active and Passive Radar Detection and Equipment
- Electromagnetic Pulses