Beijing Landview Mapping Information Technology Co.

Beijing, China

Beijing Landview Mapping Information Technology Co.

Beijing, China
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Liu S.,Beijing Normal University | Bai J.,Beijing Normal University | Jia Z.,Beijing Normal University | Jia L.,Wageningen University | Zhou H.,Beijing Landview Mapping Information Technology Co.
Hydrology and Earth System Sciences | Year: 2010

Evapotranspiration (ET) was estimated from 1981-2005 over Wushen County located in the Mu Us Sandland, China, by applying the Advection-Aridity model, which is based on the complementary relationship hypothesis. We used National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR), Moderate Resolution Imaging Spectroradiometer (MODIS), and meteorological data. Our results show that the estimated daily ET was about 4.5% higher than measurements using an Eddy Covariance (EC) system after forcing energy balance closure over an alfalfa field from 22 July 2004 to 23 August 2004. At a regional scale, the estimated monthly ET was about 8.7% lower than measurements using the EC system after forcing energy balance closure over an alfalfa field in August 2004. These results were about 3.0% higher than ET measurements by microlysimeter over sand dunes during June 1988. From 1981 to 2005, the average annual ET and precipitation levels were 287 mm and 336 mm, respectively, in Wushen County. The average annual ET varied from 230 mm in western parts of Wushen County to 350 mm in eastern parts of the county. Both inter-annual and seasonal variations in ET were substantial in Wushen County. The annual ET was 200-400 mm from 1981-2005, and the seasonal pattern of ET showed a single peak distribution. The cumulative ET during the June-September 2004 period was 250 mm, which was 87% of the total annual ET. The annual ET, precipitation, and the maximum Normalized Difference Vegetation Index (NDVImax) showed positive correlations temporally and spatially.


Wang L.,Beijing Normal University | Gong P.,Beijing Normal University | Gong P.,University of California at Berkeley | Ying Q.,Beijing Normal University | And 3 more authors.
International Journal of Remote Sensing | Year: 2010

In this paper we present an improved watershed segmentation algorithm for settlement mapping from medium resolution satellite data over plain areas in China. The algorithm can increase the computational efficiency of the fastest reported watershed segmentation algorithm by 30-40%. We apply this method to a selected study area in southern Hebei Province, China. We acquired a Landsat Enhanced Thematic Mapper Plus (ETM+) image over this area in May 2000, two Landsat Thematic Mapper (TM) images in August 2004 and April 2005, and two Beijing-1 satellite images in May 2006 and May 2007. The three types of images have three similar spectral bands (green, red and near-infrared) with similar spatial resolution (30-32 m). Only the red and near-infrared bands were used in image segmentation for settlement area extraction. The extracted settlement results are compared with manual interpretation results by two people. We assumed the human interpretation results are of higher accuracy than the segmentation results. Our results indicated that our settlement area extraction method is effective. With high quality images, the overall accuracies are nearly 94%, the kappa coefficient can be greater than 0.85. © 2010 Taylor & Francis.


Ran Q.,Beijing Landview Mapping Information Technology Co. | Chi Y.,CAS Institute of Remote Sensing | Wu S.,Twenty First Century Aerospace Technology Co. | Wen Q.,Twenty First Century Aerospace Technology Co.
Journal of Remote Sensing | Year: 2013

A parameter optimization method with adjustment of integration time is proposed with analysis of the imaging process and the affecting factors. An imaging parameter setting model is brought up. The model parameter calculation and selection are discussed. Specific post-processing of the images acquired with the proposed method is analyzed. Experiment is carried out with Beijing-1 small satellite data for optimized imaging and comparison. Results show that images acquired with the optimized method have wider dynamic range and higher radiometric resolution, and with advanced information entropy and signal noise ratio.


Wang Z.,Twenty First Century Aerospace Technology Co. | Wu S.,Twenty First Century Aerospace Technology Co. | Liu C.,Beijing Landview Mapping Information Technology Co. | Sun X.,Beijing Landview Mapping Information Technology Co. | James N.,Surrey Satellite Technology
32nd Asian Conference on Remote Sensing 2011, ACRS 2011 | Year: 2011

High-performance Earth Observation small satellite "Beijing-1" (DMC+4) was launched by 3M rocket at Plesetsk Cosmodrome of Russia on 27th October, 2005. The small satellite had successfully operated for 5 years of its design lifetime and it is safely entering the extended operating period by now. This paper introduces the In-orbit operating management strategies which include telemetry analysis, battery maintenance, data selected download based on satellite cloud atlas, and balance of task and lifetime for Beijing-1 small satellite associated with its performances and characteristics. The application of those management strategies has promoted the output and achieved long term operation of the satellite.


Yan M.,Beijing Landview Mapping Information Technology Co. | Wang Z.,Beijing Landview Mapping Information Technology Co. | Wang Z.,Twenty First Century Aerospace Technology Co. | He S.,Beijing Landview Mapping Information Technology Co. | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

The obvious vertical strip and chromatic aberration exist in the raw images obtained from the linear push-broom CCD, due to the different response among CCD detectors, the odd/even effect raised in signal transfer and the inconsistency of electronic link outside CCD array. In this paper, one relative radiometric correction method based on dark target image to calculate the bias coefficient and stable light target image to calculate the gain coefficient is discussed, taking the Beijing-1 small satellite panchromatic image as an example. This method is independent of the statistic characteristics of the corrected image, not only can remove the strip noise and the eliminate chromatic aberration, but also can make the color balance of the image, and is suitable for the relative radiometric calibration of linear push-broom CCD remote sensing image without calibration device onboard. © 2011 SPIE.


Ji W.,Twenty First Century Aerospace Technology Co. | Wang Z.,Beijing Landview Mapping Information Technology Co. | Wen Q.,Twenty First Century Aerospace Technology Co.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

Urban grass is the interference object of vegetable species recognition. Therefore choose an instance of urban grass to retrieve the spectrum curve of interference vegetation. The spectrum retrieval of vegetation species includes three steps, 1) the Hyperspectral image preprocessing, 2) the high fidelity image fusion, and 3) the purity endmember extraction. Firstly, the Hyperspectral image is preprocessed including the removal of bad bands, the radiance calibration, and the FLAASH atmospheric correction. Secondly, the Gram-Schmidt fusion method which has an advantage of spectral high fidelity was employed to fuse the Hyperspectral image and the high spatial panchromatic image. Thirdly, the grass reference vectors was applied in masking the fusion image and then the minimum noise fraction was used to forward and inverse transform the masking image. The pixel purity index of image was calculated after de-noising and then the threshold range was determined to obtain the region of interest that has high purity. The principal component analysis was adopted to forward transform the visible, near infrared, shortwave infrared channels respectively and then the first and second bands of each channel were selected. The optimum index factor was used to acquire the eigenvalues of optimum bands combination and then the N-dimensional visualization was applied in extracting study area endmember of grass species. Finally the spectrum curve of urban grass was retrieved from the average endmember spectral of original fusion image. © 2014 SPIE.


Wu Q.,CAS Institute of Remote Sensing Applications | Chi Y.-B.,CAS Institute of Remote Sensing Applications | Wang Z.-Y.,Beijing Landview Mapping Information Technology Corporation Ltd
Beijing Youdian Daxue Xuebao/Journal of Beijing University of Posts and Telecommunications | Year: 2010

A smoothing-based additive-noise estimation method of static image based on local homogeneity measurement is proposed. In order to enhance the difference of homogeneity measurement values between pixels, Cauchy distribution function is selected as the kernel function for proposed measurement method of the image homogeneity. The anisotropic diffusion based smoothing method is also used for extracting the real image boundaries. After excluding sub-images including real boundaries of the whole image, the most homogeneous sub-images are determined according to the defined threshold value. Then, standard deviation values of these sub-images are calculated. Finally, the median value of these values is extracted as the estimated value of the image noise. Furthermore, there is no need to involve with any human interaction in implementation of the proposed noise estimation method. Experiments show that the proposed method possesses higher estimation accuracy and better robustness for additive-noise estimation after comparing with other filter-based noise estimation methods.


Zhou H.,Beijing Landview Mapping Information Technology Co. | Chi Y.,Beijing Landview Mapping Information Technology Co. | Wang Z.,Twenty First Century Aerospace Technology Co. | Wen Q.,Twenty First Century Aerospace Technology Co. | Wang A.,Beijing Landview Mapping Information Technology Co.
32nd Asian Conference on Remote Sensing 2011, ACRS 2011 | Year: 2011

Duerbote Mogolian Autonomous County (Duerbote County for short), an important part of Zhalong Wetland, located in the farming-pastoral zone of North China, whose ecological environment is fragile, therefore, studying the wetlands landscape pattern change of this district has great significance. In this paper, the Landsat-ETM+ image acquired on August 11 2001 and Beijing-1 small satellite multi-spectral image acquired on August 30 2007 were selected to take a research on wetlands landscape pattern change in Duerbote County. Firstly, in order to improve change detection precision, relative radiometric calibration for the two temporal images was done based on "PIFs" method. Secondly, the object-oriented method with visual interpretation method was used for wetlands classification, meanwhile the high resolution panchromatic image of Beijing-1 small satellite was chosen for precision evaluation. Finally, the landscape pattern characteristic and its dynamic change were analyzed through several appropriate landscape pattern indices such as Fractal Dimension (FD), Landscape Diversity Index (H), Dominance Index (D) and the Internal Habitat Fragmentation Index (FI). The results show that in Duerbote County from 2001 to 2007, the values of H and FI ascend while the values of FD and D descend, which demonstrates the wetlands landscape pattern in Duerbote County turns more complex, and climate warming and strengthening of human activities are the important factors to lead to the dynamic change of the wetlands landscape pattern.


Wu Q.,CAS Institute of Remote Sensing Applications | Wu Q.,Beijing Landview Mapping Information Technology Co. | Chi Y.-B.,CAS Institute of Remote Sensing Applications | Wang Z.-Y.,Beijing Landview Mapping Information Technology Co.
Guangdian Gongcheng/Opto-Electronic Engineering | Year: 2010

To undertake analysis of CCD noise effect on lossless compression of remote sensing images, ISO/IEC standard images and UK-DMC multispectral images were selected. The ISO/IEC standard test images were encoded with JPEG2000-lossless compression method after being contaminated with different levels of simulated CCD noise based on CCD noise model. Using the encoded noise image, the change of compression ratios of the images with different noise levels was investigated. Furthermore, the analysis of noise effect on data transmission efficiency was undertaken by using noise-contaminated multispectral images. Based on experimental results, it is indicated that the compression ratio and data transmission efficiency will decrease once the image is contaminated by CCD noise. With regard to CCD noise, the shot and readout noise modeled as Poisson noise and thermal and dark current noise modeled as Gaussian noise are principal factors for the decrease of lossless compression efficiency. The impulse noise induced by detector malfunction has the least effect on the decrease of lossless compression efficiency.


Sun P.,Beijing Landview Mapping Information Technology Co. | Li D.,Beijing Landview Mapping Information Technology Co. | Liu C.,Beijing Landview Mapping Information Technology Co. | James N.,Surrey Satellite Technology
32nd Asian Conference on Remote Sensing 2011, ACRS 2011 | Year: 2011

Due to the affections of the factors such as satellite orbit injection error, earth gravity, atmosphere drag, solar perturbation, the LTAN of solar synchronize orbit satellite will drift. This paper takes the high-performance EO satellite "Beijing-1" as an example to analysis its LTAN variation trend for more than 5 years combined with the characteristics of its body-mounted solar array. Yaw strategy has been applied to improve the power generating performance and effectively reduce the passive affection of LTAN Drift on Body-Mounted Solar Array that is useful for long term operation of satellite.

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