نتایج جستجو برای: maintain soil moisture

تعداد نتایج: 317372  

2015
A. González-Zamora N. Sánchez E. Olmedo J. Martínez-Fernández

An increasing number of permanent soil moisture measurement networks are nowadays providing the means for validating new remotely sensed soil moisture estimates such as those provided by the ESA’s Soil Moisture and Ocean Salinity (SMOS) mission. Two types of in situ measurement networks can be found: small-scale (100-10000 km2), which provide multiple ground measurements within a single satelli...

2006
Daniel Sabel

Soil moisture information is an important factor in the fields of hydrology, meteorology and climatology. For hydrological applications, soil moisture data with a spatial resolution of 1 km is often requested. Current remote sensing methods are limited to a spacial resolution of 25–50 km. This study was motivated by the need to improve the resolution of soil moisture information. The aim was to...

2007
Nicolas Baghdadi Maelle Aubert Olivier Cerdan Laurent Franchistéguy Christian Viel Eric Martin Mehrez Zribi Jean François Desprats

Soil moisture is a key parameter in different environmental applications, suchas hydrology and natural risk assessment. In this paper, surface soil moisture mappingwas carried out over a basin in France using satellite synthetic aperture radar (SAR)images acquired in 2006 and 2007 by C-band (5.3 GHz) sensors. The comparisonbetween soil moisture estimated from SAR data and in situ measurements s...

Journal: :Remote Sensing 2018
Yaping Xu Lei Wang Kenton W. Ross Cuiling Liu Kimberly Berry

Droughts can severely reduce the productivity of agricultural lands and forests. The United States Department of Agriculture (USDA) Southeast Regional Climate Hub (SERCH) has launched the Lately Identified Geospecific Heightened Threat System (LIGHTS) to inform its users of potential water deficiency threats. The system identifies droughts and other climate anomalies such as extreme precipitati...

2016
Yuki Kojima Ryo Shigeta Naoya Miyamoto Yasutomo Shirahama Kazuhiro Nishioka Masaru Mizoguchi Yoshihiro Kawahara

Soil moisture is an important property for agriculture, but currently commercialized soil moisture sensors are too expensive for many farmers. The objective of this study is to develop a low-cost soil moisture sensor using capacitors on a film substrate and a capacitive touch integrated circuit. The performance of the sensor was evaluated in two field experiments: a grape field and a mizuna gre...

2011
R. M. Parinussa T. R. H. Holmes M. T. Yilmaz W. T. Crow

For several years passive microwave observations have been used to retrieve soil moisture from the Earth’s surface. Low frequency observations have the most sensitivity to soil moisture, therefore the current Soil Moisture and Ocean Salinity (SMOS) and future Soil Moisture Active and Passive (SMAP) satellite missions observe the Earth’s surface in the L-band frequency. In the past, several sate...

2014
D. K. Gupta

The microwave response of bare soil surfaces is influenced by a variety of parameters such as surface roughness, vegetation density, soil texture and soil moisture. It makes the soil moisture estimation process more complex. In such condition, the estimation of the soil moisture using microwave data with fast and less complex computing technique is a significant area of research today. The arti...

Journal: :Remote Sensing 2014
Shai Sela Tal Svoray Shmuel Assouline

Robust estimation of soil moisture using microwave remote sensing depends on extensive ground sampling for calibration and validation of the data. Soil surface sealing is a frequent phenomenon in dry environments. It modulates soil moisture close to the soil surface and, thus, has the potential to affect the retrieval of soil moisture from microwave remote sensing and the validation of these da...

Journal: :Remote Sensing 2015
Fabio Castaldi Angelo Palombo Simone Pascucci Stefano Pignatti Federico Santini Raffaele Casa

Soil moisture hampers the estimation of soil variables such as clay content from remote and proximal sensing data, reducing the strength of the relevant spectral absorption features. In the present study, two different strategies have been evaluated for their ability to minimize the influence of soil moisture on clay estimation by using soil spectra acquired in a laboratory and by simulating sa...

2007
Elfatih A. B. Eltahir Ralph M. Parsons

This paper presents a hypothesis regarding the fundamental role of soil moisture conditions in land-atmosphere interactions. We propose that wet soil moisture conditions over any large region should be associated with relatively large boundary layer moist static energy, which favors the occurrence of more rainfall. Since soil moisture conditions themselves reflect past occurrence of rainfall, t...

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