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In healthcare, the Nine Hole Peg Test (NHPT) is considered a standard for assessing hand dexterity. A digital version of the classic Nine-Hole Peg Test – the dNHPT - has been developed that allows digital measurement of hand function. The prototype of this dNHPT was investigated in this study with test-retest and crossover design with 32 healthy adults. Pearson Correlation Coefficient and Bland-Altman diagram were used to analyze concurrent validity. Intraclass Correlation Coefficients (ICC), standard error or measurement (SEM) and smallest detectable change (SDC) were used to determine test-retest and interrater reliability. Our results showed a moderate concurrent validity (r = 0.592). The Bland Altman analysis showed an estimated a mean difference of −2.47 between the dNHPT in comparison with the conventional NHPT. The dNHPT demonstrated good test-retest reliability (ICC: 0.75, SEM: 0.89, SDC: 2.47) and high interrater reliability (ICC: 0.76). To conclude, the dNHPT can contribute to objectify the measurement of hand dexterity without losing its most compactness and simplicity as the most important properties of NHPT.

Fractional vegetation cover (FVC) is one of the most important criteria for surface vegetation status. This criterion corresponds to the complement of gap fraction unity at the nadir direction and accounts for the amount of horizontal vegetation distribution. This study aims to directly validate the accuracy of FVC products over crops at coarse resolutions (1 km) by employing field measurements and high-resolution data. The study area was within an oasis in the Heihe Basin, Northwest China, where the Heihe Watershed Allied Telemetry Experimental Research was conducted. Reference FVC was generated through upscaling, which fitted field-measured data with spaceborne and airborne data to retrieve high-resolution FVC, and then high-resolution FVC was aggregated with a coarse scale. The fraction of green vegetation cover product (i.e., GEOV1 FVC) of SPOT/VEGETATION data taken during the GEOLAND2 project was compared with reference data. GEOV1 FVC was generally overestimated for crops in the study area compared with our estimates. Reference FVC exhibits a systematic uncertainty, and GEOV1 can overestimate FVC by up to 0.20. This finding indicates the necessity of reanalyzing and improving GEOV1 FVC over croplands. [ABSTRACT FROM PUBLISHER]

The development of efficient and systematic ground-based spatial sampling strategies is critical for the validation of medium-resolution satellite-derived leaf area index (LAI) products, particularly over heterogeneous land surfaces. In this paper, a new sampling strategy based on high-resolution vegetation index prior knowledge (SSVIP) is proposed to generate accurate LAI reference maps over heterogeneous areas. To capture the variability across a site, the SSVIP is designed to 1) stratify the nonhomogeneous area into zones with minimum within-class variance; 2) assign the number of samples to each zone using Neyman optimal allocation; and 3) determine the spatial distribution of samples with a nearest neighbor index. The efficiency of the proposed method was examined using different vegetation types and pixel heterogeneities. The results indicate that the SSVIP approach can properly divide a heterogeneous area into different vegetation cover zones. Whereas the LAI reference maps generated by SSVIP attain the target accuracy of 0.1 LAI units in cropland and broadleaf forest sites, the current sampling strategy based on vegetation type has a root mean square error (RMSE) of 0.14 for the same number of samples. SSVIP was compared with the current sampling strategy at 24 VALERI sites, and the results suggested that samples selected by SSVIP were more representative in the feature space and geographical space, which further indicated the reasonable validation over heterogeneous land surfaces. [ABSTRACT FROM PUBLISHER]

The Solar Backscatter Ultraviolet Sounder (SBUS) is one of the 11 main payload instruments onboard Feng Yun-3 (FY-3), the second generation of Chinese polar orbit meteorological satellites. This paper presents the results of SBUS instrument calibration, and data and product validation during the prelaunch and postlaunch periods. Topics include the instrument prelaunch calibration and characterization, in-orbit monitoring, validation of the ozone profiles retrieved from the FY-3 SBUS measurements, and an application of the retrievals to monitoring the 2011 Arctic ozone depletion. For the prelaunch calibration of SBUS, the estimated uncertainty of laboratory calibration is approximately 4.7%. The in-orbit solar irradiance measurements indicate that the diffuser reflectivity degraded approximately 15% for the 252-nm channel, and 3% to 5% for the other 11 channels during a 12-mo period. Using ozone vertical profiles retrieved from National Oceanic and Atmospheric Administration Solar Backscatter Ultraviolet (SBUV)/2s as a “truth,” the initial comparison of ozone profiles between FY-3 SBUS and SBUV/2s finds that the relative percent bias of the FY-3 SBUS with the SBUV/2 results is good. The averaged differences range over to ±7% for FY-3A SBUS and ±6% for FY-3B SBUS. The SBUS ozone profile retrievals reveal that the spring 2011 Arctic ozone depletion mainly resulted from a sharp ozone decrease in the upper troposphere to lower stratosphere, which accounts for 70% to 80% of the total ozone loss. [ABSTRACT FROM AUTHOR]