Title :
Two-load radiometer precision and accuracy
Author :
Goodberlet, Mark A. ; Mead, James B.
Author_Institution :
ProSensing Inc., Amherst, MA, USA
Abstract :
The advent of fast computers and digital signal processing permits many aspects of radiometer operation to be decided in real time so that precision and accuracy are maximized. Closed-form expressions for precision, optimal antenna/load dwell times, and maximum chopping period are derived for a class of radiometers that uses two loads to calibrate its measurements of antenna brightness temperature. The importance of load brightness temperature selection emphasizes the need to develop "cold" calibration loads that can operate at ambient temperature. A method of incorporating critical thermistor data into the radiometer brightness temperature calibration can be used to help stabilize measurements against drift and may permit radiometers to operate without thermal control in some low-accuracy applications.
Keywords :
calibration; geophysical signal processing; geophysical techniques; microwave measurement; radiometry; receiving antennas; remote sensing; antenna brightness temperature; brightness temperature calibration; closed-form expression; cold calibration load; digital signal processing; load brightness temperature selection; maximum chopping period; microwave radiometry; microwave receiver; optimal antenna load dwell time; radiometer; real time operation; thermal control; thermistor data; Antenna measurements; Brightness temperature; Calibration; Closed-form solution; Digital signal processing; Loaded antennas; Radio control; Radiometry; Temperature control; Thermistors; Calibration; microwave radiometry; microwave receivers; radiometry;
Journal_Title :
Geoscience and Remote Sensing, IEEE Transactions on
DOI :
10.1109/TGRS.2005.860206
