Optical and Radio Frequency Refractivity Fluctuations from High Resolution Point Sensors: Sea Breezes and Other Observations
Abstract
High bandwidth communications and optical/RF weapons systems are being developed that are limited by atmospheric absorption and accumulated phase distortions. The need and ability to mitigate these effects depends on their magnitudes. It is difficult to numerically model the magnitudes of Cn2 numerically and results are frequently off by an order of magnitude or more. To refine models or conduct climatologically studies for Cn2 requires direct measurements to identify the underlying factors and provide a clear understanding of the phenomena. In situ measurements of Cn2 are extremely sparse at RF wavelengths. This thesis utilized high speed measurements of the humidity, temperature and wind speed collected on a 10 m tower at a coastal location to simultaneously examine the optical and RF Cn2. The humidity data were collected with a high-speed infrared humidity sensor. A three axis sonic anemometer provided wind data and a fine wire temperature sensor as well as the sonic anemometer provided temperature data. All the data were sampled at 20 Hz. This study examined a subset of 251 days of data collected at Marina, California to investigate the relative variations of optical and RF magnitudes of Cn2 and the underlying atmospheric phenomena.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2007
- Accession Number
- ADA467200
Entities
People
- Douglas A. Macpherson
Organizations
- Naval Postgraduate School