Noise wave analysis of Dicke and noise injection radiometers: Complete S parameter analysis and effect of temperature gradients
Article first published online: 17 SEP 2010
Copyright 2010 by the American Geophysical Union.
Volume 45, Issue 5, October 2010
How to Cite
2010), Noise wave analysis of Dicke and noise injection radiometers: Complete S parameter analysis and effect of temperature gradients, Radio Sci., 45, RS5004, doi:10.1029/2009RS004198.(
- Issue published online: 17 SEP 2010
- Article first published online: 17 SEP 2010
- Manuscript Accepted: 7 MAY 2010
- Manuscript Revised: 8 MAR 2010
- Manuscript Received: 5 MAY 2009
- microwave radiometers;
- thermal gradient;
- noise waves;
 The performance analysis of microwave radiometers is often simplified by assuming that most or all circuits are perfectly matched and that all are at the same physical temperature. However, the increasingly high performance demanded of future instruments requires assessment of their performance, including the following effects: actual complex S parameters of the various subsystems (nonzero insertion losses, imperfect matching, finite isolation etc.), physical temperature gradients etc. in order to correct them in software, when it is not possible to eliminate these nonidealities by design. A full noise-wave analysis is presented in this paper. Linearity and bias errors are evaluated, as well as their sensitivity to thermal gradients and characterization errors. Finally, the required intervals between calibrations can be estimated based on this analysis.