Details

Autor(en) / Beteiligte

• Colliander, A.
• Jackson, T.J.
• Chan, S.K.
• O'Neill, P.
• Bindlish, R.
• Cosh, M.H.
• Caldwell, T.
• Walker, J.P.
• Berg, A.
• McNairn, H.
• Thibeault, M.
• Martínez-Fernández, J.
• Jensen, K.H.
• Asanuma, J.
• Seyfried, M.S.
• Bosch, D.D.
• Starks, P.J.
• Holifield Collins, C.
• Prueger, J.H.
• Su, Z.
• Lopez-Baeza, E.
• Yueh, S.H.

Titel

An assessment of the differences between spatial resolution and grid size for the SMAP enhanced soil moisture product over homogeneous sites

Ist Teil von

• Remote sensing of environment, 2018-03, Vol.207, p.65-70

Ort / Verlag

Goddard Space Flight Center: Elsevier Inc

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Satellite-based passive microwave remote sensing typically involves a scanning antenna that makes measurements at irregularly spaced locations. These locations can change on a day to day basis. Soil moisture products derived from satellite-based passive microwave remote sensing are usually resampled to a fixed Earth grid that facilitates their use in applications. In many cases the grid size is finer than the actual spatial resolution of the observation, and often this difference is not well understood by the user. Here, this issue was examined for the Soil Moisture Active Passive (SMAP) enhanced version of the passive-based soil moisture product, which has a grid size of 9-km and a nominal spatial resolution of 33-km. In situ observations from core validation sites were used to compute comparison metrics. For sites that satisfied the established reliability and scaling criteria, the impact of validating the 9-km grid product with in situ data collected over a 9-km versus a 33-km domain was very small for the sites studied (0.039 m3/m3 unbiased root mean square difference for the 9-km case versus 0.037 m3/m3 for the 33-km case). This result does not mean that the resolution of the product is 9-km but that for the conditions studied here the soil moisture estimated from in situ observations over 9-km is a close approximation of the soil moisture estimated from in situ observations over the 33-km resolution. The implication is that using the enhanced SMAP product at its grid resolution of 9-km should not introduce large errors in most applications. •Comparison of SMAP soil moisture validation at 9-km and 33-km spatial scales.•In situ soil moisture at 9-km scale correlates well with soil moisture at 33-km.•Validation metrics similar at 9-km and 33-km scales for the SMAP product.•The SMAP product can be used at 9-km scale with most applications.