Jinnian Wang

A Spectral Angle Distance-Weighting Reconstruction Method for Filled Pixels of the MODIS Land Surface Temperature Product

Land surface temperature (LST) is an important parameter in the physics of land surface processes, but a large number of pixels are often filled as zero due to cloud, heavy aerosols, and so on in the Moderate-resolution Imaging Spectroradiometer (MODIS) LST product. This letter presents the spectral angle distance (SAD)-weighting reconstruction (SADWER) method of reconstruction of zero-filled pixels of the MODIS LST product. It relies on the hypothesis that pixels with the same land-cover type have nearly the same LST in a localized area. SAD can measure the similarity of land-cover types of different pixels, and pixels with higher land-cover similarity can contribute more to the reconstruction using the weighting method. The result shows that the reconstruction ratio could be as high as 95% using only the SADWER method and nearly 100% after spatial filter postprocessing. The reconstruction accuracy is validated using artificially generated 20-, 50-, and 80-km-diameter concentrically filled areas in both forest and crop land-cover types. The statistical result shows that the standard deviations of the reconstruction errors are less than 2 Kelvin.

A Field Imaging Spectrometer System

A Field Imaging Spectrometer System (FISS) based on a cooling area CCD was developed. This paper describes the principle, structural design, main technology parameters and data processing flow, as well as some application experiments using the FISS instrument. The FISS instrument shows huge potential applications in geology, food, agriculture, forestry and other respective field.

A solution model of System's Interior Orientation Parameters (SIOP) of the multi-digital camera system based on the DLT algorithm

According to the characteristic of multi-digital cameras system, the paper presents the concept of Systems Interior Orientation Parameters (SIOP) and verifies that the SIOP acquired from calibration in the inside field can effectively improve the accuracy and efficiency of data processing of multi-digital cameras system. Importantly, the paper builds a solution model of SIOP and verifies the feasibility of this solution model by experiment. Above all, the major research in the paper gives an answer to the question that how to calibrate the multi-digital cameras system efficiently and accurately.

The Spectral Crust project—Research on new mineral exploration technology

Considering Chinas increasing demands for energy and mineral resources, this article describes challenges in current mineral exploration, summarizes new mineral exploration techniques, and introduces the basic concept, research aims, and implementation of the Spectral Crust project. This project will use hyperspectral technology and remote sensing to map the Earths land surface and mineral alterations and to establish a crustal hyperspectral database. The Spectral Crust project will align with national strategy, strengthen technological innovation, and improve mineral resource detection by spaceborne and airborne hyperspectral remote sensing, establish platforms for ground-spectra measurement and core scanning, compilation, and analysis, and promote data integration. This project has great strategic significance as it will help advance the development of remote sensing technology and Chinas mineral exploration technology and will solve key problems in direct and deep mineral prospecting.

Correlations between water reflectance spectra and chlorophyll concentration in Qinghai Lake

Qinghai Lake, which is the largest salt water lake in China and a major obstacle in the burgeoning Eastward desertification from West China, has a vital role in the ecological sustainability of Tibetan Plateau. From the ecological perspective, the environment of Qinghai Lake became worse since the end of last century, while due to its remoteness, the field surveys in this area are difficult to carry out. Chlorophyll-a concentration in water is one of the most basic indices for water quality. In this paper, the water reflectance of Qinghai Lake was measured using ASD Fieldspec spectrometer and the water samples were collected simultaneously. The Chlorophyll-a concentration was correlated to the features of the hyperspectral reflectance, and the results showed that the first-derivative reflectance is better correlated with the water chlorophyll-a concentration.