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Methods of determining the spatial response nonlinearities of radiometers
Applied Optics
|January 23, 2010
Summary
Radiometer spatial nonuniformity can cause significant errors. This study shows how to correct for these errors by comparing filled and unfilled fields of view, preventing over 18% inaccuracy.
Area of Science:
- Radiometry
- Optical Engineering
- Metrology
Background:
- Radiometer response often varies with target position within the field of view.
- Spatial nonuniformity is a common challenge in accurate radiometric measurements.
Purpose of the Study:
- To analyze the impact of spatial response nonuniformity in radiometers.
- To develop a method for correcting errors caused by nonuniformity.
- To quantify potential errors in a specific radiometer model.
Main Methods:
- Examined the effects of spatial nonuniformity using a symmetrical uniform source.
- Related radiometer output with an unfilled field of view to output with a filled field of view.
- Analyzed a Huggins Mark IX radiometer.
Main Results:
- Spatial nonuniformity can lead to significant measurement errors.
- Errors exceeding 18% were identified in the Huggins Mark IX radiometer due to nonlinearity.
- A method was proposed to mitigate errors by comparing filled and unfilled fields of view.
Conclusions:
- Spatial response nonuniformity is a critical factor affecting radiometer accuracy.
- Ignoring nonlinearity caused by nonuniformity can result in substantial errors.
- The proposed method offers a way to improve the reliability of radiometric measurements.
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