Instrumentation for the measurement of the spectral density of a radiation impulse
Abstract
Natural electrical processes in atmospheric clouds produce individual radio noise impulses of very short duration, as do corona discharges in the air on or near high-voltage conductors. The spectral source-strengths of these impulses are virtually unknown at frequencies above 1 GHz. Besides being of general interest, source-strength information is needed to assess the merits of certain speculative ideas of applications in the fields of lightning hazard avoidance, and passive detection of certain missiles. The source-strength of a radiation impulse can be quantified by measuring its spectral density at some standard distance (e.g., 10 km) from its point of origin. This report describes the equipment, calibrations, field procedures and data reduction methods developed by Megapulse, Incorporated to measure impulse source-strength. The technique was demonstrated by a limited program of 910 MHz cloud-noise measurements at Prospect Hill, Waltham, Massachusetts. Preliminary results are given and compared with the (mostly lower frequency) data reported by other observers. The Megapulse technique could easily be extended to still higher frequencies.
- Publication:
-
Final Technical Report Megapulse
- Pub Date:
- December 1981
- Bibcode:
- 1981mega.rept.....K
- Keywords:
-
- Atmospheric Electricity;
- Cloud Physics;
- Clouds (Meteorology);
- Electrical Measurement;
- Calibrating;
- Data Reduction;
- Density Measurement;
- Impulses;
- Missile Detection;
- Noise Measurement;
- Communications and Radar