Abstract
This article examined in detail microwave radiometer functioning algorithm with synchronously using of the two types of pulse modulation: amplitude pulse modulation and pulse-width modulation. This allows a zero-radiometer measurement method to realize when the fluctuation effect of the receiver gain and the influence of its own noise changes are minimized. A zero balance automatically maintains in radiometer. The antenna signal is indirectly determined through the signal duration that controls the pulse-width modulation. An analytical expression of the fluctuation sensitivity was obtained in a general form. From its analysis gain in sensitivity, conditions were defined by the optimizing of the radiometer input knot’s construction. Three modifications of the radiometer input knot were researched. Fluctuation sensitivity at different measurement range was determined for modification of the radiometer input knot.
Highlights
It is well known that study of microwave appearance of various objects of earth’s surface provides fundamentally different physical self-descriptiveness than using only optical and infrared earth remote sensing [1] [2]
A development of microwave remote sensing systems with low energy consumption intended for working in natural conditions and especially on the side refers to a difficult problem
Traditional approaches often lead to mutually exclusive solutions; the implementation of stringent requirements for the microwave radiometers is impossible without searching for new approaches, methods and solutions
Summary
It is well known that study of microwave appearance of various objects of earth’s surface provides fundamentally different physical self-descriptiveness than using only optical and infrared earth remote sensing [1] [2]. The average of the halfcycle modulation power of invariable reference noise signal generator is regulated by changing of the duration of its action This led to the simplification of the input receiving block scheme (microwave switch and noise generator), improving of the linearity of calibration radiometer equation by the simple adjustment of the reference signal. This method of mixing the reference and measured signals (in different ways pulse-modulated) led to a considerable simplification of input block design. A new modification of the zero functioning principle of microwave radiometers by weak signal changing was considered, and the possibility of fluctuation sensitivity and stability of these systems were analyzed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
