This paper was to assess the reliability of RADARSAT-2 quad-polarization SAR data in rice mapping and yield estimation. Five scenes of RADARSAT-2 images were acquired in the rice season of 2011 in Jiangsu Province, China. Ground experiments were conducted in accordance with the acquisition dates. For rice mapping, optimal dual-polarization combination was obtained by ratio change detection. The accuracy of rice mapping by HV/HH reaches 79.2% and by VV/HH reaches 84.9%. For rice yield estimation, an improved scheme based on assimilation method has been put forward. ORYZA2000 model was coupled with an empirical rice backscattering model to simulate the dual-polarization ratios. SCE-UA optimization algorithm is employed to determine the optimal set of input parameters during the re-initialization process. As a result, an improved accuracy has been confirmed.
In this study, three scenes of Landsat TM/ETM+ images covering Beijing area were used to examine the relationship
between the UHI and land use and land cover (LULC) changes, as well as between the UHI and vegetation greenness.
The brightness temperatures, LULC, and NDVI were retrieved from the calibrated images. The results showed that the
urban or built-up area in Beijing has increased by 4.07% from 1988 to 2005, with nearly 5.7% of vegetated land lost
during the same period. The barren area was also increased in this period as large number of land was taken over for
urban construction. Seasonal pattern of UHI was obvious with highest UHI intensity observed in summer and lowest in
winter. Moreover, with the rapid urbanization, the extent of UHI expanded with newly hot spots emerged surrounding the
central urban area. In addition, higher NDVI or vegetation coverage leads to higher land surface temperature (LST) in
winter and lower LST in summer. This was due to the different thermal characteristic between vegetated area and
non-vegetated area. Therefore, increasing vegetation coverage can be beneficial to the mitigation of UHI effect in urban
area in hot season while to keep the land warmer in cold season.
Tibetan Plateau has a crucial impact on the atmospheric circulation changes of Asia and even the northern hemisphere
and southern hemisphere, directly affecting the formation and evolution of weather and climate of China, and therefore
the studying on weather, climate and their evolving mechanism over Qinghai-Tibet Plateau is of great significance, and
this studying is helpful for improving accuracy of forecast disaster weather. Tibetan Plateau is the magnifying glass of
global climate change too. The system of ecology and the environment in Tibetan Plateau is very fragile and very
sensitive to global climate change, so Tibetan Plateau is a window of studying global climate change. Due to the special
geographical conditions of the Tibetan Plateau, the weather stations are scarce over the plateau region, especially in its
western region. The introduction and application of satellite remote sensing data on studying on the Tibetan Plateau, in
particular, is very important and very necessary. Using satellite remote sensing data, some areas of the Tibetan Plateau is
classified into several surface types, regional distributions of the Surface parameters are calculated and discussed
according to each type. Further more, each distribution map and straight-bar figure of the Surface parameters is given
out. The results indicate: All the regional distributions are characteristic by their terrain nature and the regional
distributions are obvious and regular. It is seen that the derived regional distributions of land surface parameters for the
whole mesoscale area are in good accordance with the land surface status.
KEYWORDS: Wave propagation, Convection, Atmospheric propagation, Climatology, Physics, Data centers, System on a chip, Environmental sensing, Data modeling, Atmospheric modeling
By using GEOS data assimilation system, we investigate the influence of TRMM precipitation products on the
structure and underlying physics of ISO in a GCM assimilation system. We get the following conclusion: 1) In 1998
summer, the strong ISO is apparently in Asia monsoon region off equator and and east equatorial Pacific region .2) 20-
30-day eastward propagation is the dominant mode of ISO near equator. 30-60-day northeastward propagation is the
dominant mode of ISO north of equator averaged over 10°N-25°N. 3) For 20-30-day eastward propagation near equator,
the wavenumver 1 intensity of control run is usually weaker than that of assimilation run and observation. For 30-60-day
northward propagation averaged over 60°E-140°E, the wavenumber 1 intensity of control run is usually stronger than
that of assimilation run and observation. 4)By comparing the correlation coefficients and RMS of Kelvin wave structure
for geopotential height and wind vector at 150hPa between control run and observation with assimilation run with
observation, we can conclude that the assimilation run are more resemble observation, especially near equator. 5) For
assimilation run, the convection, which occurred between high and low geopotential height at 150hPa or between
easterly and westerly and the two anticyclone at 150hPa off equator, are more organized than that for control run
compared with observation. The better Kelvin wave features for the eastward-propagating MJO in the tropic from the
assimilation with TRMM precipitation imply that latent heating is very important in exciting equatorial MJO.
By using a hybrid model tier-1 that is coupled in the Indo-Pacific tropical ocean, we perform a set of 10 ensemble
runs with different initial condition for two-season period that starts from November 1st and May 1st respectively in 1982
though 2004. The tier-1.5 that is only coupled from India Ocean to dateline and prescribes model monthly climatology
plus observed SSTA in east tropical Pacific is also used to perform another suite of 10 ensemble runs with same initial
conditions. The sensitivity of Asia monsoon and Australian monsoon to SST in central and eastern tropical Pacific has
been investigated. The results of experiments suggest that, 1) the climatology precipitation bias has close relationship
with climatology SST bias which possibly cause overabundant rainfall over Arab Sea and Bay of Bengal, northward shift
rain belt over West Pacific in summer, deficient rainfall of ITCZ over tropical Pacific in summer, too long south branch
of ITCZ over southern Pacific in winter. 2) To east of dateline, the precipitation external variance and internal variance
in tier-1.5 are much larger than those in tier-1.5. 3) The similar signal to noise ratio or error to external ratio as well as
anomaly correlation over Asia monsoon region between in tier-1 and tier-1.5 suggests that precipitation predictability
over Asia monsoon region has little relationship with the improvement of central and east Pacific SST. 4) The
improvement spatial correlation in winter by tier-1.5 over El Nino region during La Nina year, especially when the cold
SST over Nino3.4 turn into warm SST suggest that the winter precipitation predictability over El Nino region can
possible be improved by SST predictability.
In this paper, a practical scheme for assimilation of multi-temporal and multi-polarization ENVISAT ASAR data in rice
crop model to map rice yield has been presented. To achieve this, rice distribution information should be obtained first by
rice mapping method to retrieve rice fields from ASAR images, and then an assimilation method is applied to use the
temporal single-polarized rice backscattering coefficients which are grouped for each rice pixel to re-initialize
ORYZA2000. The assimilation method consists in re-initializing the model with optimal input parameters allowing a
better temporal agreement between the rice backscattering coefficients retrieved from ASAR data and the rice
backscattering coefficients simulated by a coupled model, i.e. the combination of ORYZA2000 and a semi-empirical rice
backscatter model through LAI. The SCE-UA optimization algorithm is employed to determine the optimal set of input
parameters. After the re-initialization, rice yield for each rice pixel is calculated, and the yield map over the area of
interest is produced finally. The scheme was applied over Xinghua study area located in the middle of Jiangsu Province
of China by using the data set of an experimental campaign carried out during the 2006 rice season. The result shows that
the obtained rice yield map generally overestimates the actual rice production situation, with an accuracy of 1133 kg/ha
on validation sites, but the tendency of rice growth status and spatial variation of the rice yield are well predicted and
highly consistent with the actual production variation.
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.