| Paper: | FR-A1.7 |
| Session: | Instruments and Calibration (Posters) |
| Time: | Friday, March 30, 09:00 - 10:20 |
| Presentation: |
Poster
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| Topic: |
Advanced radiometer techniques: |
| Title: |
CALIBRATION OF CLOCK SCANNING MICROWAVE INTERFEROMETRIC RADIOMETER |
| Authors: |
Cheng Zhang; Chinese Academy of Sciences | | |
| | Hao Liu; Chinese Academy of Sciences | | |
| | Ji Wu; Chinese Academy of Sciences | | |
| Abstract: |
Current microwave imterferometric radiometer (MIR) systems are facing the challenges of employing complicated antenna arrays with large numbers of antenna elements to achieve the required high spatial resolution. Most of the ambitious MIR concepts are suffering from the cost of having hundreds of antenna and receiver elements and the resulting large-scaled digital correlator. Recently, a new array configuration using Clock Scan (CS) was brought forward to simplify the antenna array, which can break the dependence of the spatial resolution on the number of the antenna elements in such a way that only simple rotation mechanism is required. The CS array is able to conveniently achieve a complete uv coverage by means of rotating the antenna elements. It is known that complete uv sampling is necessary for the MIR array to retrieve a good brightness temperature map. Another important advantage of CS-MIR is that, the CS array is quit suitable for space application. It is easy for CS array to make a folding and deployment design to break through the launch vehicle envelope, and hence to achieve a quite large aperture.
With the advantages of simple and deployable array configuration, the CS-MIR has wide potential applications. It is first dedicated to the concept of Solar Polar Orbit Telescope (SPORT) mission, a space science mission in China for monitoring the interplanetary Coronel Mass Ejections (CME) from solar polar orbit (SPO). Later on, CS-MIR is assessed to apply in Earth observation from Geostationary Earth Orbit (GEO). Recently, a ground demonstrator of CS-MIR working at L- band is developed to validate this new concept. This paper describes the calibration and initial results of this ground CS-MIR system.
With the benefits of using digital I/Q demodulation, high level digital correlation, build-in match load and noise source, and especially the special rotation scan of the CS array, the calibration of the CS-MIR is much simpler than the SMOS/MIRAS system. The simplicity of the CS-MIR is mainly lies in three aspects: No need to correct the quadrature errors of the digital I/Q demodulation; no need to use PMS subsystem for visibility demoralization and no need to use correlated noise injection for amplitude and phase calibration.
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