Filters








273 Hits in 3.6 sec

SMOS prototype algorithm for detecting autumn soil freezing

Kimmo Rautiainen, Tiina Parkkinen, Juha Lemmetyinen, Mike Schwank, Andreas Wiesmann, Jaakko Ikonen, Chris Derksen, Sergei Davydov, Anna Davydova, Julia Boike, Moritz Langer, Matthias Drusch (+1 others)
2016 Remote Sensing of Environment  
Acknowledgments This research was supported by European Space Agency projects "SMOS + Innovation: Application of SMOS data for the characterization of the freeze/thaw cycle and the retrieval of permafrost  ...  information" (ESA contract 4000105184/12/I-BG), "SMOS + Frost2 Study" (ESA contract 4000110973/14/NL/FF/lf), and the Finnish Academy Centre of Excellence in Atmospheric Science (272041).  ...  Method Background Our soil F/T-state retrieval algorithm is based on detecting the annual changes in soil permittivity along with soil freezing and thawing.  ... 
doi:10.1016/j.rse.2016.01.012 fatcat:g2reh3pubnd4vav7rmhsjch3e4

Utilization of ancillary data sets for SMAP algorithm development and product generation

Peggy E. O'Neill, Erika Podest, Eni G. Njoku
2011 2011 IEEE International Geoscience and Remote Sensing Symposium  
Once launched in late 2014/early 2015, the Soil Moisture Active Passive (SMAP) mission will provide high resolution global mapping of soil moisture and its freeze/thaw state every 2-3 days.  ...  In order for soil moisture and freeze/thaw to be retrieved accurately from SMAP microwave data, a variety of global static and dynamic ancillary data are required.  ...  overall soil moisture or freeze/thaw retrieval accuracy, and its compatibility with similar choices made by the SMOS mission.  ... 
doi:10.1109/igarss.2011.6049703 dblp:conf/igarss/ONeillPN11 fatcat:3kizzfh25fgnrbbychbbuersx4

The scale-dependence of SMOS soil moisture accuracy and its improvement through land data assimilation in the central Tibetan Plateau

Long Zhao, Kun Yang, Jun Qin, Yingying Chen, Wenjun Tang, Hui Lu, Zong-Liang Yang
2014 Remote Sensing of Environment  
Meanwhile, very few retrievals are available in winter due to the presence of frozen soil and snow cover, and the accuracy of ascending retrievals degrades during transition when diurnal freezing-thawing  ...  This finding indicates the applicability of SMOS retrievals is scaledependent.  ...  Acknowledgment This research was financially supported by National Natural Science Foundation of China (grant nos. 41325019 and 41190083), and the National Natural Science Foundation of China (grant no  ... 
doi:10.1016/j.rse.2014.07.005 fatcat:reeduhjqdnhxdfaicrohbruly4

USING SMOS PASSIVE MICROWAVE DATA TO DEVELOP SMAP FREEZE/THAW ALGORITHMS ADAPTED FOR THE CANADIAN SUBARCTIC

P. Kalantari, M. Bernier, K. C. McDonal, J. Poulin
2015 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences  
SMOS time series data were analyzed to examine seasonal variations of soil freezing, and to assess the impact of land cover on the Freeze/Thaw cycle.  ...  The average accuracies are 80% and 84% for the soil freeze period, and soil thaw period respectively. The comparison is limited because of the small number of validation pixels.  ...  The delay between the soil freezing and the water freezing, and also this delay in the thawing period cause errors.  ... 
doi:10.5194/isprsarchives-xl-1-w5-365-2015 fatcat:pojxws7txzglbav7povu5djioq

Soil dielectric characterization during freeze–thaw transitions using L-band coaxial and soil moisture probes

Alex Mavrovic, Renato Pardo Lara, Aaron Berg, François Demontoux, Alain Royer, Alexandre Roy
2021 Hydrology and Earth System Sciences  
Both instruments were used to characterize the permittivity of soil samples undergoing several freezethaw cycles in a laboratory environment.  ...  To validate and improve satellite microwave data products, precise and reliable estimations of the relative permittivity (εr=ε/ε0=ε′-jε′′; unitless) of soils are required, particularly for frozen soils  ...  We would like to thank Bilal Filali for his contribution to the design and manufacture of the probe, along with Simone Bircher, Arnaud Mialon, Yann Kerr and the entire CES-BIO team in Toulouse for their  ... 
doi:10.5194/hess-25-1117-2021 fatcat:geatovzsejb73h3v7a52kpezfm

Utilizing Earth Observations of Soil Freeze/Thaw Data and Atmospheric Concentrations to Estimate Cold Season Methane Emissions in the Northern High Latitudes

Maria Tenkanen, Aki Tsuruta, Kimmo Rautiainen, Vilma Kangasaho, Raymond Ellul, Tuula Aalto
2021 Remote Sensing  
Here, we use a novel way to integrate remote sensing soil freeze/thaw (F/T) status from SMOS satellite to better capture the seasonality of methane emissions in the northern high latitude.  ...  The SMOS F/T data provide daily information of soil freezing state in the northern latitudes, and in this study, the data is used to define the cold season in the high latitudes and, thus, improve our  ...  Bristol (UNIVBRIS), University of Exeter, University of Urbino (UNIURB), and University of Wisconsin-Madison (UofWI) for performing high-quality CH 4 measurements at global sites and making them available  ... 
doi:10.3390/rs13245059 fatcat:322kg24w6fgxhgbtsvlampjwpy

Assimilating SMOS Brightness Temperature for Hydrologic Model Parameters and Soil Moisture Estimation with an Immune Evolutionary Strategy

Feng Ju, Ru An, Zhen Yang, Lijun Huang, Yaxing Sun
2020 Remote Sensing  
In this study, a special assimilation scheme was proposed to jointly estimate parameters and soil moisture (SM) by assimilating brightness temperature (TB) from the Soil Moisture and Ocean Salinity (SMOS  ...  To evaluate the effectiveness of the scheme, the estimated SM sets are compared with in-situ observations and SMOS products in Maqu on the Tibetan Plateau.  ...  and SMOS SM retrievals.  ... 
doi:10.3390/rs12101556 fatcat:sj6ier2ipbh7rectez3j7i4ohm

Development and assessment of the SMAP enhanced passive soil moisture product

S.K. Chan, R. Bindlish, P. O'Neill, T. Jackson, E. Njoku, S. Dunbar, J. Chaubell, J. Piepmeier, S. Yueh, D. Entekhabi, A. Colliander, F. Chen (+21 others)
2018 Remote Sensing of Environment  
moisture and freeze-thaw state every two to three days using a radar and a radiometer operating at L-band frequencies.  ...  existing hydrological applications and foster new ones.  ...  While the loss necessarily ended the operational 134 production of several key soil moisture and freeze/thaw data products that rely on the 135 high-resolution radar data, it also spurred the development  ... 
doi:10.1016/j.rse.2017.08.025 pmid:32943797 pmcid:PMC7493025 fatcat:oteov5sqjrfydmxifee2flu6by

The NASA Soil Moisture Active Passive (SMAP) mission: Overview

Peggy O'Neill, Dara Entekhabi, Eni Njoku, Kent Kellogg
2010 2010 IEEE International Geoscience and Remote Sensing Symposium  
Its mission design consists of L-band radiometer and radar instruments sharing a rotating 6-m mesh reflector antenna to provide high-resolution and highaccuracy global maps of soil moisture and freeze/  ...  The combined active/passive microwave soil moisture product will have a spatial resolution of 10 km and a mean latency of 24 hours.  ...  and applications needs that could be wholly or partially met by a mission devoted to measuring surface soil moisture and its freeze/thaw state.  ... 
doi:10.1109/igarss.2010.5652291 dblp:conf/igarss/ONeillENK10 fatcat:azquozvhubezba5vboglmekuci

Retrieving landscape freeze/thaw state from Soil Moisture Active Passive (SMAP) radar and radiometer measurements

Chris Derksen, Xiaolan Xu, R. Scott Dunbar, Andreas Colliander, Youngwook Kim, John S. Kimball, T. Andrew Black, Eugenie Euskirchen, Alexandre Langlois, Michael M. Loranty, Philip Marsh, Kimmo Rautiainen (+3 others)
2017 Remote Sensing of Environment  
Acknowledgments The research described in this publication was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and  ...  Work at the Imnavait sites was funded by the National Science Foundation Division of Polar Programs Arctic Observatory Network grant numbers 0632264 and 1107892 Canadian contributions to the SMAP mission  ...  In addition to overall flag agreement, counts of freeze and thaw omission and commission errors ('false freeze' retrievals vs. 'false thaw' retrievals) are also tabulated.  ... 
doi:10.1016/j.rse.2017.03.007 fatcat:gmj3oabjbbcntomguudtta5s4y

NASA Soil Moisture Active Passive mission status and science performance

Simon Yueh, Dara Entekhabi, Peggy O'Neill, Eni Njoku, Jared Entin
2016 2016 IEEE International Geoscience and Remote Sensing Symposium (IGARSS)  
This paper provides a status summary of the calibration and validation of the SMAP instruments and the quality assessment of its soil moisture and freeze/thaw products.  ...  The Soil Moisture Active Passive (SMAP) observatory was launched January 31, 2015, and its L-band radiometer and radar instruments became operational since mid-April 2015.  ...  The preliminary Cal/Val assessment has indicated excellent quality of the soil moisture and freeze/thaw products.  ... 
doi:10.1109/igarss.2016.7729020 dblp:conf/igarss/YuehEONE16 fatcat:ffe5hirjv5h6hgqyiolyqtyly4

Proxy Indicators for Mapping the End of the Vegetation Active Period in Boreal Forests Inferred from Satellite-Observed Soil Freeze and ERA-Interim Reanalysis Air Temperature

Kristin Böttcher, Kimmo Rautiainen, Mika Aurela, Pasi Kolari, Annikki Mäkelä, Ali N. Arslan, T. Andrew Black, Sampsa Koponen
2018 PFG – Journal of Photogrammetry Remote Sensing and Geoinformation Science  
We tested for the first time the usability of satellite-observed soil freeze from the Soil Moisture and Ocean Salinity (SMOS) instrument as a proxy indicator for the end of vegetation active period (VAPend  ...  The time when soil freeze commenced over the large SMOS pixel can be employed to estimate VAPend (R 2 0.84, RMSE 7.5 days), defined as the time when the photosynthetic capacity of the forest drops below  ...  and freeze references to determine the soil freeze and thaw state.  ... 
doi:10.1007/s41064-018-0059-y fatcat:qft7tub3r5dytnpkdsh3d7z65q

Evaluation of the validated Soil Moisture product from the SMAP radiometer

P. O'Neill, S. Chan, A. Colliander, S. Dunbar, E. Njoku, R. Bindlish, F. Chen, T. Jackson, M. Burgin, J. Piepmeier, S. Yueh, D. Entekhabi (+22 others)
2016 2016 IEEE International Geoscience and Remote Sensing Symposium (IGARSS)  
NASA's Soil Moisture Active Passive (SMAP) mission launched on January 31, 2015 into a sunsynchronous 6 am/6 pm orbit with an objective to produce global mapping of high-resolution soil moisture and freeze-thaw  ...  Additional improvements (including optimization of retrieval algorithm parameters and upscaling approaches) and methodology expansions (including increasing the number of core sites, model-based intercomparisons  ...  NASA's SMAP (Soil Moisture Active Passive) mission launched on January 31, 2015 with a goal of providing global mapping of soil moisture and freeze/thaw state every 2-3 days using data from an L-band radiometer  ... 
doi:10.1109/igarss.2016.7729023 dblp:conf/igarss/ONeillCCDNBCJBP16 fatcat:sweledpu25cpldkayyo6df5jhm

Temperature effects on L-band vegetation optical depth of a boreal forest

Mike Schwank, Anna Kontu, Arnaud Mialon, Reza Naderpour, Derek Houtz, Juha Lemmetyinen, Kimmo Rautiainen, Qinghuan Li, Philippe Richaume, Yann Kerr, Christian Mätzler
2021 Remote Sensing of Environment  
Furthermore, the model's ability to explain L-VOD retrieved from brightness temperatures of the "Soil Moisture and Ocean Salinity" (SMOS) satellite over the "Sodankylä grid cell" is investigated.  ...  This temperature response, observed at different temporal-and spatial scales, is captured by the proposed L-VOD model and explained by freezing tree sap-water and the dependence of water permittivity on  ...  Level 2 Soil Moisture" (Contract no. 4000125649).  ... 
doi:10.1016/j.rse.2021.112542 fatcat:tccgv4uwxbfxratbwwfur7a5nm

Spatial Variability of L-Band Brightness Temperature during Freeze/Thaw Events over a Prairie Environment

Alexandre Roy, Peter Toose, Chris Derksen, Tracy Rowlandson, Aaron Berg, Juha Lemmetyinen, Alain Royer, Erica Tetlock, Warren Helgason, Oliver Sonnentag
2017 Remote Sensing  
representation of the strong F/T signal (i.e., T B increases and decreases when soil freezing and thawing, respectively).  ...  Passive microwave measurements from space are known to be sensitive to the freeze/thaw (F/T) state of the land surface.  ...  Conflicts of Interest: The authors declare no conflict of interest. Remote Sens. 2017, 9, 894  ... 
doi:10.3390/rs9090894 fatcat:tkc2oscsejbp3itnj27jyemkde
« Previous Showing results 1 — 15 out of 273 results