U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            PARINUSSA, R - Vrije Universityitem
                                            Holmes, Thomasitem
                                            Crow, Wadeitem
                                            DE JEU, R.A.M. - Vrije University
  Submitted to: Meeting Abstract
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 2/1/2012
                                    Publication  Date: 2/5/2012
                                    Citation: Parinussa, R.M., Holmes, T.R., Crow, W.T., De Jeu, R. 2012. Large scale evaluation of soil moisture retrievals from passive microwave observations [abstract]. Meeting Abstract. 2012 CDROM.Interpretive Summary:
                                Technical Abstract: For several years passive microwave observations have been used to retrieve surface soil moisture from the Earth’s surface. Several satellite sensors such as the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) and WindSat have been used for this purpose using multi-channel observations. Large scale validation of these retrievals is generally hampered by a lack of ground-based observation networks with sufficient spatial density to be accurately up-scaled to the resolution of satellite-based soil moisture retrievals. In response to this challenge, two new global evaluation techniques have been proposed which circumvent the need for extensive ground-based soil moisture observations. The first technique (Rvalue) is based on calculating the correlation coefficient between known rainfall errors and Kalman filter analysis increments realized during the assimilation of remotely sensed soil moisture into an antecedent precipitation index. The second technique is based on a so-called Triple Collocation (TC) analysis, which is a statistical tool for estimating the root mean square error (RMSE) of a set of three linearly related data sources with independent error structures.

These two newly-developed, large-scale soil moisture evaluation techniques are applied for cross-verification on a global scale. Both techniques are also used to determine the sensitivity of soil moisture retrievals to land surface temperature estimates by artificially degrading the satellite signal used for the retrieval of this important parameter. Instead of coincident land surface temperature observations from the same satellite, external sources for land surface temperature are also evaluated using the same evaluation techniques. Finally, both day- and night-time observations are evaluated separately to determine the impact of the different physical conditions during day- and night-time.

The evaluation results produced by the Rvalue and TC soil moisture verification approaches show a high mutual consistency (R2 = 0.95), which lends confidence to their interpretation as robust evaluation techniques. They show that the quality of soil moisture retrievals has a strong link with density of the vegetation cover of the observed area. This link was also found when evaluating the different scenarios for the land surface temperature input and when comparing soil moisture retrievals from day- and night-time observations. This study could be used as a framework to evaluate retrievals from the recent Soil Moisture and Ocean Salinity (SMOS) and future Soil Moisture Active and Passive (SMAP) missions.

USDA is an equal opportunity provider and employer.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov