Forest tree species identification and its response to spatial scale based on multispectral and multi-resolution remotely sensed data.

The effect of spatial scale could not be ignored in identification results of forest types generated by multi-resolution images, and the influence of adding texture information from remote sensing data on the accuracy of forest trees species identification at different spatial resolutions has not been clearly addressed. To clarify this situation, we studied the Wangyedian forest farm in Northeast China, by using quasi-synchronous and geographical coordinate matched multi-resolution satellite observations (six spatial resolution levels: 1, 2, 4, 8, 16 and 30 m) which were supported with GF-1 PMS (pan and multi-spectra sensor), GF-2 PMS, GF-1 WFV (wide field view) and Landsat-8 OLI (operational land imager) and could investigate any possible correlations between spatial resolution and the recognition result, besides the influence of adding texture information. Five dominant tree species were classified and identified using Support Vector Machine (SVM) classifier.

[Analysis on Diurnal Variation of Chlorophyll-a Concentration of Taihu Lake Based on Optical Classification with GOCI Data].

Chlorophyll-a (Chl-a) concentration is one of the most important parameters for the analysis of inland water quality. Remote sensing data with the advantages of wide spatial area and multi-temporal monitoring has been applied as a reliable source of Chl-a concentration. However, as optical characteristics of inland water bodies are complex with high spatial and temporal (diurnal) variations, there are still limitations to estimate Chl-a concentration with traditional remote sensing data and single model.

The Extraction Model of Paddy Rice Information Based on GF-1 Satellite WFV Images.

In the present, using the characteristics of paddy rice at different phenophase to identify it by remote sensing images is an efficient way in the information extraction. According to the remarkably properties of paddy rice different from other vegetation, which the surface of paddy fields is with a large number of water in the early stage, NDWI (normalized difference water index) which is used to extract water information can reasonably be applied in the extraction of paddy rice at the early stage of the growth. And using NDWI ratio of two phenophase can expand the difference between paddy rice and other surface features, which is an important part for the extraction of paddy rice with high accuracy.

[Impact of Vegetation Structure on Drought Indices Based on MODIS Spectrum].

The drought indices based on MODIS spectral reflectance data are widely used for drought characterization and monitoring in agricultural context. Based on the PROSAIL model and MODIS observational data in Shandong in 2010, the present paper studied the impact of vegetation structure of leaf area index and physiological growth cycle on MODIS spectral drought index. The results showed that the reflectance of three MODIS bands in spectrum of near-infrared and shortwave infrared changes significantly with leaf water content of vegetation.

[Modeling continuous scaling of NDVI based on fractal theory].

Scale effect was one of the very important scientific problems of remote sensing. The scale effect of quantitative remote sensing can be used to study retrievals' relationship between different-resolution images, and its research became an effective way to confront the challenges, such as validation of quantitative remote sensing products et al. Traditional up-scaling methods cannot describe scale changing features of retrievals on entire series of scales; meanwhile, they are faced with serious parameters correction issues because of imaging parameters' variation of different sensors, such as geometrical correction, spectral correction, etc.

[NDVI difference rate recognition model of deciduous broad-leaved forest based on HJ-CCD remote sensing data].

The present paper takes Chuzhou in Anhui Province as the research area, and deciduous broad-leaved forest as the research object. Then it constructs the recognition model about deciduous broad-leaved forest was constructed using NDVI difference rate between leaf expansion and flowering and fruit-bearing, and the model was applied to HJ-CCD remote sensing image on April 1, 2012 and May 4, 2012. At last, the spatial distribution map of deciduous broad-leaved forest was extracted effectively, and the results of extraction were verified and evaluated.

[Mangrove canopy species discrimination based on spectral features of Geoeye-1 imagery].

Based on Geoeye-1 high spatial resolution images and field canopy hyperspectral reflectance of five mangrove communities located at Beibu Gulf, this paper verified the capability of Geoeye-1 imagery for mangrove canopy species identification by utilizing spectral information. The research investigated that: (1) in the spectrum range between 350 and 1 100 nm, the mangrove canopy reflectance exhibited optimum separability in six wavebands (435, 469, 523, 677, 751 and 761 nm); (2) three mangrove species could be effectively identified through the pixel-based spectrum operation, while the Bruguiera acquired the highest producer accuracy up to 93.03%; (3) species end member of Bruguiera extracted directly from the combined imagery conducted on hyperspectral hypothesis performed higher precision than the field training samples behaved.

[Dynamic monitoring of summer maize planting information for spatial and temporal variations in Huanghuaihai plain during 2000-2010].

In order to give consideration to the change information of summer maize planting area and spatial distribution in Huanghuaihai plain, the present paper combined statistical analysis and remotely sensed classification technology to extract summer maize based on MODIS EVI images. The results showed high accuracy (> 67.35%) with the TM-derived in spatial distribution and high correlation coefficient with the agriculture statistics in planting areas at city level (R2 > 0.

[Retrieval of dust fraction of atmospheric aerosols based on spectra characteristics of refractive indices obtained from remote sensing measurements].

Mineral dust is an important chemical component of aerosol, which has a significant impact on the climate and environmental changes. The spectral behavior of aerosol refractive indices at four wavelengths from 440 to 1 020 nm was analyzed based on one year observation obtained from Beijing AERONET site. The real parts of refractive index (n) in each band did not differ greatly, however the imaginary parts (k) showed a significant difference due to the absorption of mineral dust in aerosol.

[Experimental study of offshore oil thickness hyperspectral inversion based on bio-optical model].

Study on the regularity of thin oil film thickness and its reflectance plays an important role in understanding the mechanism of offshore oil slick and ocean hydrocarbon resources exploration. In this work, the thin oil film thickness of biological optical model is established, and introduced the simplified model of inversion thin oil film thickness information by using one single-band or by using two-band ratio image data. With the quantitative inversion test of thin oil film thickness through the natural shallow water and the crude oil sample, the variation rules of between oil spectral parameters and the thin oil film thickness are obtained.

[Error analysis of the land surface temperature retrieval using HJ-1B thermal infrared remote sensing data].

Error analysis is playing an important role in the application of the remote sensing data and model. A theoretical analysis of error sensitivities in land surface temperature (LST) retrieval using radiance transfer model (RT) is introduced, which was applied to a new thermal infrared remote sensing data of HJ-1B satellite(IRS4). The modification of the RT model with MODTRAN 4 for IRS4 data is mentioned.

[Analysis of directional characteristics of winter wheat canopy spectra].

The bidirectional reflectance factors vary as the incidence directions and the view angles change. At present the remote sensing is almost at nadir, therefore it is possible to improve the accuracy of remote sensing application by reasonably selecting the looking angle, solar zenith angle, and so on. Based on the multidirectional spectra of winter wheat canopy at several critical growth stages, the paper quantitatively analyzed the sensitivity of narrowband bidirectional reflectance to view planes, view zenith angle, solar zenith angle, growth stage, and band by using anisotropy factor (ANIF) and anisotropy index (ANIX).

[Wavelet analysis and its application in denoising the spectrum of hyperspectral image].

In order to remove the sawtoothed noise in the spectrum of hyperspectral remote sensing and improve the accuracy of information extraction using spectrum in the present research, the spectrum of vegetation in the USGS (United States Geological Survey) spectrum library was used to simulate the performance of wavelet denoising. These spectra were measured by a custom-modified and computer-controlled Beckman spectrometer at the USGS Denver Spectroscopy Lab. The wavelength accuracy is about 5 nm in the NIR and 2 nm in the visible.

[A target-highlighting method in multispectral remote sensing].

In order to highlight target in multispectral remote sensing and overcome the human error caused by threshold, a new method is proposed here. Image of target similarity is firstly calculated by spectral energy level matching (SEM) algorithm and as a band added to original image; Then, band normalization is performed on the new image to reduce the effects caused by the order of magnitude in different bands; Finally, a false color image that highlights the target is made by RGB composed of the first three bands (3, 2, 1) in MNF transformation. Results from the experiment of highlighting the main rock-type tuffaceous siltstone in Hatu area, Xinjiang province, China show that (1) the new method can highlight target for the increment of target's information and weights during the process of transformation by adding a band representing target's similarity to the original image.

[Spectral response analysis of offshore thin oil slicks].

Hyperspectral data of thin oil slicks have some spectral response characteristics, and an experiment of offshore thin oil slicks was designed to measure and analyze their reflectance by using ASD hyperspectral instrument. With the oil slick thickness changing, its color varied from rainbow sheen slick to fuchsine sheen slick, kelly sheen slick, aqua sheen slick, silver sheen slick and light sheen slick. The result suggested that different thin oil slicks have different characteristics, some thin oil slicks could change the reflectance at 440 nm which is the spectral absorption peak value of chlorophyll, and the best hyperspectral band to distinguish the different offshore thin oil slicks is located in the range between 350 and 440 nm.

Feasibility of reflectance spectroscopy for the assessment of soil mercury contamination.

Conventional methods for investigating soil Hg contamination based on raster sampling and chemical analysis are time-consuming and relatively expensive. The objective of this study was to develop a rapid method for investigating Hg concentration in suburban agricultural soils of the Nanjing region using reflectance spectra within the visible-near-infrared (VNIR) region. Several spectral pretreatments (absorbance, Kubelka-Munk transformations and their derivatives) were applied to the reflectance spectra to optimize the accuracy of prediction.