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The Soil Moisture Active Passive (SMAP) observatory was launched January 31, 2015, and its L-band radiometer and radar instruments became operational during April 2015. The SMAP radiometer has been operating flawlessly, however the radar transmitter ceased operation on July 7. This paper provides a summary of the calibration and validation of the SMAP instruments and the current quality assessment...
In this paper we discuss the steps taken for the calibration and validation of the Soil Moisture Active Passive (SMAP) L-band radiometer. We discuss the use of multiple vicarious sources such as the global ocean mean and celestial cold-sky emissions along with various spacecraft maneuvers to calibrate out gain, offset, antenna pattern of the radiometer. We present initial validation comparison of...
The Soil Moisture Active Passive (SMAP) mission, launched January 31, 2015, provides global observations of 1.4 GHz Earth thermal emissions from space [1] through its L-band radiometer. Although SMAP's radiometer passband lies within the protected 1.4–1.427 GHz band, both unauthorized in-band transmitters as well as out-of-band emissions from transmitters operating at frequencies adjacent to this...
NASA's Soil Moisture Active Passive (SMAP) mission launched on January 31, 2015 into a sun-synchronous 6 am/6 pm orbit with an objective to produce global mapping of high-resolution soil moisture and freeze-thaw state every 2–3 days using an L-band (active) radar and an L-band (passive) radiometer. The SMAP radiometer began acquiring routine science data on March 31, 2015 and continues to operate...
This presentation illustrates and discusses the possibility of SMAP-Sentinel combined product for the recovery phase of the SMAP mission post radar failure. Initial assessment and results are preliminary and show great promise.
The NASA Soil Moisture Active Passive (SMAP) mission produced a daily landscape freeze/thaw product (L3_FT_A) at 3-km spatial resolution derived from ascending and descending orbits of SMAP high-resolution L-band (1.4 GHz) radar measurements. Following the loss of the SMAP radar in July 2015, coarser (36-km) footprint passive microwave retrievals from the SMAP radiometer were used to derive an alternative...
The SMAP Level 4 soil moisture (L4_SM) product provides global estimates of surface and root zone soil moisture, along with other land surface variables and their error estimates. These estimates are obtained through assimilation of SMAP brightness temperature observations into the Goddard Earth Observing System (GEOS-5) land surface model. The L4_SM product is provided at 9 km spatial and 3-hourly...
The NASA Soil Moisture Active Passive (SMAP) mission Level 4 Carbon (L4_C) product provides model estimates of Net Ecosystem CO2 exchange (NEE) incorporating SMAP soil moisture information as a primary driver. The L4_C product provides NEE, computed as total respiration less gross photosynthesis, at a daily time step and approximate 14-day latency posted to a 9-km global grid summarized by plant functional...
Surface soil moisture was retrieved globally by systematically correcting for the effects of vegetation and soil surface roughness. The retrieval is enabled by employing physical-models of radar forward scattering for individual vegetation types to account for vegetation scattering and absorption, and by constraining the surface roughness effect using time-series observations. The L-band SMAP multi-polarized...
In this paper we describe remote sensing methods with optical and radar sources to monitor aboveground carbon in forests. We move from forest/non-forest mapping, through forest type mapping (conifer, deciduous and mixed) to major species mapping. Biomass combined with species is required to compute the aboveground carbon. Biomass for forests needs accurate height measurements and allometric equations...
This paper presented experimental results discussing the potential of millimeterwave SAR for forest remote sensing on the individual tree level. As can be seen from the experimental results, although there is a certain amount of canopy penetration, a significant part of the signal response is received from the tree crowns. This provides both interesting perspectives for an analysis of forest volumes...
Two extraction models applied in estimating forest height and above-ground biomass (AGB) were developed using the X-band Interferometric Synthetic Aperture Radar (InSAR) data, which was acquired from the China airborne SAR system in 2013 covering part of forested area in northeast China. The models using multi-passes InSAR data for the estimations of forest height and AGB were introduced respectively...
Almost concurrent imagery from Landsat-5 and Radarsat-2 are examined separately and in combination to maximize the accuracy of a simple classification of a typical multi-use grassland region in western Canada. Almost all classifications were of sufficient accuracy to be used in an operational sense. Landsat seven band classification was the most accurate, but was deemed less likely to be useful as...
Wetlands, very sensitive and valuable ecosystem can be monitored in terms of water surfaces dynamics as well as vegetation characterisation and monitoring exploiting satellite data. The synergy between the recently launched Sentinel1 and Sentinel2 satellites have been investigated over the Poyang and Anhui lakes in PR China. Results highlight the gain in terms of operationality with a very high revisit...
PolSAR features have great significance in application of vegetation classification, which can explain the scattering mechanism of the vegetation; the decision tree classifier not only can obtain good classification accuracy, but also can adjust the classification results, as well as make full use of PolSAR features to explain the scattering mechanism of the targets because of its simple and hierarchical...
Rangelands in Australia cover approximately 80 percent of the continent and include a diverse group of relatively undisturbed ecosystems such as tropical savannas, woodlands, shrublands and grasslands. It is important to monitor and understand change in the rangelands so that effective actions can be taken to maintain ecological, economic and social values in Australia. Efficient use of feed resources...
In this paper, we extend the product model from common texture to the case of multitexture. With the generalized Gamma distribution (GΓD) being the texture distribution, a multitexture model for multilook polarimetric SAR data is proposed and the estimation of parameters is performed based on the method of matrix log-cumulant. As far as the diagonal random texture matrix is concerned, the textures...
Desertification of semi-arid grasslands is a serious problem for economic development and ecological preservation. Using the Hunshandake Sandy Lands as an example, we present an overview of monitoring of land desertification using two different data sources including TM and MODIS data. The driving mechanisms of Hunshandake Sandy Land desertification are also discussed.
This paper presents two research applications exploiting unused metadata resources in novel ways to aid data discovery and exploration capabilities. The results based on the experiments are encouraging and each application has the potential to serve as a useful standalone component or service in a data system.
The data deluge we face does not only overwhelm us with sheer data volume, but also with an increasing variety of multi-dimensional datasets. As is more and more accepted, spatio-temporal data sets often can be represented through a common unifying paradigm, namely datacubes. In this contribution, we present datacubes as a common modeling paradigm upon which flexible, scalable services can be offered...
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