THERMOSONDE 2007: In-Situ Measurement of Optical Turbulence
Abstract
This report updates the 1982 Thermosonde technical report, by documenting the current configuration. The wires in the thermosonde are arranged as two legs of a Wheatstone bridge, which generates a voltage proportional to the resistance difference. The telemetry signal now consists of digital signal "counts," rather than analog frequency changes, the multiple segment calibration relationship has been replace by a single straight line, and a new, lower signal calibration input point has been added to the calibration source. Synchronous detection of the telemetry signal has allowed the overall gain to be increased to approximately 600,000. Calibration voltages are read within 1mV for a range of voltages from the minimum, which is the noise floor of about 10 mV (equivalent to about 0.0005K up to a maximum output of 2.0 V. For a modest CT2 value o of 0.0002K2M-213, the uncertainty in Cn2 is down to 1.5 percent. For a stronger CT2 of 0.001 , overall Cn2 uncertainty is below 0.5% at low altitudes and starts to noticeably increase al20 km, reaching a 4% uncertainty at 30 km due to pressure uncertainties.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 07, 2007
- Accession Number
- ADA551490
Entities
People
- E. A. Murphy
- G. Clement
- G. Y. Jumper
- K. Robinson
- P. Tracy
- R. R. Beland
Organizations
- Air Force Research Laboratory