A Rotating fan-beam scatterometer (RFSCAT), which provides a set of different incidence and azimuth angle
combinations and wide continuous swath coverage, will be flown on the Chinese-French Oceanography Satellite
(CFOSAT). In this paper, a pre-processing algorithm is developed to estimate the backscatter coefficient (σ0) of
RFSCAT, which includes the procedures of system distortion correction, thermal noise removal, internal signal
calibration, and elimination of the observing geometry effects. The algorithm is then tested using the experimental data
from an airborne campaign. The estimated σ0 are consistent with Nscat-2 geophysical model function (GMF), indicating
that the pre-processing chain acts well for RFSCAT.
For ocean observation, the wind velocity over water is one major concern. Spaceborne microwave scatterometers can
provide global, all-day, all-time, high-accuracy, high-resolution and short cycle wind velocity observations over the
earth's bodies of water. For a microwave scatterometer system, backscattering coefficient accuracy and spatial resolution
are two important parameters. And they are used to evaluate the performance of a scatterometer. High quality
scatterometer data intends to have both high accuracy measurement of backscattering coefficient and high resolution.
However, these two important parameters are restricted by each other, and cannot reach optimal level at the same time.
Therefore, a compromise between the two variables is necessary for the system design of a scatterometer.
In this paper, simulation results of conically scanned pencil beam scatterometers are presented. Analysis of
backscattering coefficient measurement accuracy under different spatial resolution conditions is also presented. With the
same instrument parameters, larger spatial resolution will increase the number of independent samples of backscattering
measurement. It is well known that the backscattering coefficient accuracy of scatterometers is decided by the SNR of
returned signal and number of independent samples. And simulation results show that the number of independent
samples plays a more important role in backscattering coefficient accuracy than SNR of the returned signal. As a result,
backscattering measurement accuracy and accuracy of retrieved wind velocity can be improved. The simulation results
and analysis can be of benefit to the system design of next generation spaceborne pencil beam scatterometers.
In this paper, the effects from mutual coupling and imbalance between channels on the interferometric correlation are analyzed. It is shown that the correlation error is mainly introduced by the phase imbalance. The phase balance of the central frequency can ensure the accuracy of the correlation phase, and the residual phase error will only reduce the coherency. Coherent/Incoherent noise calibration can correct the channel imbalance related interferometric correlation errors.
In this paper, a scheme of microwave interferometric radiometer for earth observation is proposed. The movement of the interferometer will produce a u-v plane coverage of the visibility function, which can be used for imaging of the brightness temperature distribution. The coverage is analyzed and some comparisons of this interferometer with that for space observation are made. The inversion method is proposed and simulation results are presented to show the possibility. Some open problems are drawn out for further researchers.
Conference Committee Involvement (3)
Earth Observing Missions and Sensors: Development, Implementation, and Characterization V
25 September 2018 | Honolulu, Hawaii, United States
Earth Observing Missions and Sensors: Development, Implementation, and Characterization IV
4 April 2016 | New Delhi, India
Earth Observing Missions and Sensors: Development, Implementation, and Characterization III
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.