Earth Resources Satellite Research Articles

An approach to monitoring mangrove extents through time-series comparison of JERS-1 SAR and ALOS PALSAR data

Between 2007 and 2010, Japan’s Advanced Land Observing Satellite (ALOS) Phased Arrayed L-band Synthetic Aperture Radar (PALSAR) captured dual polarization HH and HV data across the tropics and sub-tropics. A pan tropical dataset of Japanese Earth Resources Satellite (JERS-1) SAR (HH) data was also acquired between 1995 and 1998. The provision of these comparable cloud-free datasets provided an opportunity for observing changes in the extent of coastal mangroves over more than a decade. Focusing on nine sites distributed through the tropics, this paper demonstrates how these data can be used to backdate and update existing baseline maps of mangrove extent. The benefits of integrating dense time-series of Landsat sensor data for both validating assessments of change and determining the causes of change are outlined. The approach is evaluated for wider application across the geographical range of mangroves in order to advance the development of JAXA’s Global Mangrove Watch (GMW) program.

Dynamic remote sensing interpretation of geological disasters in Nanping City of Fujian Province using CBERS serial data

It is important to expand the application of domestic satellite data such as China- Brazil Earth Resource Satellite( CBERS) images for backtracking interpretation research in such areas year- by- year. In this paper,with the Nanping City in northwestern Fujian Province as the study area,the authors collected the related eleven CBERS images acquired during 1999- 2008,and established the image interpretation keys to the disasters. The visual interpretation method based on GIS platform was used in combination with the field studies,and a total of 2 059 interpreted disaster points were obtained during the past 8 years,with no data obtained in 2001 and 2002. The results of dynamic analysis show that the geological disasters in he study area were mainly the shallow landslides that concentratedly happened in 2000 and 2005. They reached 582 and 766 sites respectively,possessed 65% of the total landslides,and were distributed near residential and traffic districts,showing heterogeneous temporal and spatial characteristics. It is held that CBERS images can be employed for dynamic survey of geological disasters.

On the effects of each term of the geopotential perturbation along the time I: Quasi-circular orbits

This paper provides a useful new method to determine minimum and maximum range of values for the degree and order of the geopotential coefficients required for simulations of orbits of satellites around the Earth. The method consists in a time integration of the perturbing acceleration coming from each harmonic of the geopotential during a time interval T. More precisely, this integral represents the total velocity contribution of a specific harmonic during the period T. Therefore, for a pre-fixed minimum contribution, for instance 1×10-8m/s during the period of time T, any harmonic whose contribution is below this value can, safely, be neglected. This fact includes some constraints in the degree and order of the terms which are present in the geopotential formula, saving computational efforts compared to the integration of the full model. The advantage of this method is the consideration of other perturbations in the dynamics (we consider the perturbations of the Sun, the Moon, and the direct solar radiation pressure with eclipses), since these forces affect the value of the perturbation of the geopotential, because these perturbations depend on the trajectory of the spacecraft, that is dependent on the dynamical model used. In this paper, we work with quasi-circular orbits and we present several simulations showing the bounds for the maximum degree and order (M) that should be used in the geopotential for different situations, e. g., for a satellite near 500km of altitude (like the GRACE satellites at the beginning of their mission) we found 35⩽M⩽198 for T=1day. We analyzed the individual contribution of the second order harmonic (J2) and we use its behavior as a parameter to determine the lower limit of the number of terms of the geopotential model. In order to test the accuracy of our truncated model, we calculate the mean squared error between this truncated model and the “full” model, using the CBERS (China-Brazil Earth Resources Satellite) satellite in this test.

Earth Observation Applications in Brazil with Focus on the CBERS Program

Abstract-Brazil is a large and diverse country and almost all remote sensing application fields can be developed there: oceanographic, agricultural, environmental, urban, etc. Some applications are instrumental for environmental governance, some are very useful for business and others are devoted to research. As part of its remote sensing development, Brazil counts on the CBERS (China-Brazil Earth Resources Satellite) Program. Applications and accomplishments of the CBERS Program are presented in this article.

New global forest/non-forest maps from ALOS PALSAR data (2007–2010)

Four global mosaics of Advanced Land Observing Satellite (ALOS) Phased Arrayed L-band Synthetic Aperture Radar (SAR) HH and HV polarization data were generated at 25m spatial resolution using data acquired annually from 2007 to 2010. Variability in L-band HH and HV gamma-naught (γ0) for forests was observed between regions, with this attributed to differences in forest structure and vegetation/surface moisture conditions. Region-specific backscatter thresholds were therefore applied to produce from each annual mosaic, a global map of forest and non-forest cover from which maps of forest losses and gain were generated. The overall agreement with forest/non-forest assessments using the Degree Confluence Project, the Forest Resource Assessment and Google Earth images was 85%, 91% and 95% respectively. Using 2007 as a baseline, decreases of 0.040 and 0.028dB (with a 0.006dB 99% confidence level) were observed in the HH and HV γ0 respectively over the same areas suggesting a decrease in forest area and/or increased smoothing of the global surface at the L-band radar observation over the four-year period. The maps provide a new global resource for documenting the changing extent of forests and offer opportunities for quantifying historical and future dynamics through comparison with historical (1992–1998) Japanese Earth Resources Satellite (JERS-1) SAR and the forthcoming (from 2014) ALOS-2 PALSAR-2 data. Four year PALSAR mosaics and the forest/non-forest data, which were generated and analyzed in this paper, are opened to the public for free downloading albeit with coarser resolutions (WWW1). Future distribution of the higher (original) resolution datasets from PALSAR as well as the ALOS-2/PALSAR-2 is planned.

Linear Spectral Mixing Model for Identifying Potential Missing Endmembers in Spectral Mixture Analysis

A problem that is frequently arising in the spectral mixture analysis is how to correctly identify the endmembers present in the scene. In the analysis of image data covering natural scenes, vegetation, bare soil, and shade/water are commonly assumed as endmembers, but other endmembers may also be present. This paper investigates an approach based on the analysis of residuals produced by the linear spectral mixing model for identifying potential missing endmembers. The basic proposition consists in assuming that larger residuals are caused by missing endmembers. The image is segmented in terms of the residuals, and the Kolmogorov-Smirnov test is applied to group segments that show similar residuals and are thus likely to include the same missing endmember. An approach to estimate the spectral response of the missing endmembers is also investigated. The proposed methodology is tested by using Thematic Mapper Landsat and Coupled Charge Device China-Brazil Earth Resources Satellite image data. In addition to vegetation, bare soil, and shade/water, two additional endmembers were included as missing endmembers (clouds and water bodies with a large load of suspended sediments). The tests have shown that the proposed methodology is capable of detecting image regions that include missing endmembers and of correctly estimating the corresponding spectral responses.

Development, application, and prospects for Chinese land observation satellites

The launching of CBERS-01 (China Brazil Earth Resource Satellite) in 1999, China’s first land observation satellite, signifies an unprecedented milestone in Chinese satellite remote sensing history. Since then, a large number of applications have been developed that drew upon solely CBERS-01 and other Chinese land observation satellites. The application development evolves from one satellite to multiple satellites, from one series of satellites to multiple series, from scientific research to industrial applications. Six aspects of the Chinese land observation satellite program are discussed in this paper: development status, data sharing and distribution, satellite calibration, industrial data applications, future prospects, and conclusion.

Systems architecture, procedural knowledge and learning by using: implications on systems integration capabilities

The objective of this article is to assess the implications of systems architecture on the establishment of organizational learning cycles, and its influence on possible forms of process integration. Dynamics of innovation of complex systems do not follow the pattern of mass-production industries. In complex systems industries there is no dominant design and each new product generation remains in a fluid phase. This article focuses on analysis of the dynamic phenomena that occur when a system performs its functions within the operational environment. By considering successive generations of the China-Brazil Earth Resources Satellite (CBERS) platform as a case study a stylized cognitive model is presented. It is argued that learning by using is practice-oriented epistemology to the extent that it requires the reflective confrontation of a previous stock of knowledge with that derived from praxis, which is concrete, dynamic and relational. Knowledge generation derived from learning by using - tacit and explicit - crystallizes a common knowledge base, allowing the refinement of subsystems designs and interfaces through successive generation of products. Systems integration capability building requires a project-based organization in order to merge operating and learning processes in a multifunctional framework.

Automated geometric correction of multispectral images from High Resolution CCD Camera (HRCC) on-board CBERS-2 and CBERS-2B

China–Brazil Earth Resource Satellite (CBERS) imagery is identified as one of the potential data sources for monitoring Earth surface dynamics in the event of a Landsat data gap. Currently available multispectral images from the High Resolution CCD (Charge Coupled Device) Camera (HRCC) on-board CBERS satellites (CBERS-2 and CBERS-2B) are not precisely geo-referenced and orthorectified. The geometric accuracy of the HRCC multispectral image product is found to be within 2–11km. The use of CBERS-HRCC multispectral images to monitor Earth surface dynamics therefore necessitates accurate geometric correction of these images. This paper presents an automated method for geo-referencing and orthorectifying the multispectral images from the HRCC imager on-board CBERS satellites. Landsat Thematic Mapper (TM) Level 1T (L1T) imagery provided by the U.S. Geological Survey (USGS) is employed as reference for geometric correction. The proposed method introduces geometric distortions in the reference image prior to registering it with the CBERS-HRCC image. The performance of the geometric correction method was quantitatively evaluated using a total of 100images acquired over the Andes Mountains and the Amazon rainforest, two areas in South America representing vastly different landscapes. The geometrically corrected HRCC images have an average geometric accuracy of 17.04m (CBERS-2) and 16.34m (CBERS-2B). While the applicability of the method for attaining sub-pixel geometric accuracy is demonstrated here using selected images, it has potential for accurate geometric correction of the entire archive of CBERS-HRCC multispectral images.

Tentative construction of satellite data management and service system for ZY-1 02C

In order to meet the management and service needs of China's first self- developed high- resolution satellite for earth resources investigation proposed by related land and resources department,the authors designed and developed the C / S- based data management subsystem and the B / S- based data services subsystem of ZY- 1 02C,with the propose of spreading the application of ZY- 1 02C data relying on the existing hardware and software environment of land and resources field. Functions such as timely storage of mass data,efficient distribution and real- time online inquiries were completed in this system. The study and development of this system can provide basic data protection for spreading utilization of ZY- 1 02C data in land and resources field and also lay a theoretical and practical foundation for the subsequent earth resource satellite application system in China which integrates many functions( such as data reception,processing,interpretation,and information sharing service) into one function.

Sub-pixel change detection for urban land-cover analysis via multi-temporal remote sensing images

Conventional change detection approaches are mainly based on per-pixel processing, which ignore the sub-pixel spectral variation resulted from spectral mixture. Especially for medium-resolution remote sensing images used in urban land-cover change monitoring, land use/cover components within a single pixel are usually complicated and heterogeneous due to the limitation of the spatial resolution. Thus, traditional hard detection methods based on pure pixel assumption may lead to a high level of omission and commission errors inevitably, degrading the overall accuracy of change detection. In order to address this issue and find a possible way to exploit the spectral variation in a sub-pixel level, a novel change detection scheme is designed based on the spectral mixture analysis and decision-level fusion. Nonlinear spectral mixture model is selected for spectral unmixing, and change detection is implemented in a sub-pixel level by investigating the inner-pixel subtle changes and combining multiple composition evidences. The proposed method is tested on multi-temporal Landsat Thematic Mapper and China–Brazil Earth Resources Satellite remote sensing images for the land-cover change detection over urban areas. The effectiveness of the proposed approach is confirmed in terms of several accuracy indices in contrast with two pixel-based change detection methods (i.e. change vector analysis and principal component analysis-based method). In particular, the proposed sub-pixel change detection approach not only provides the binary change information, but also obtains the characterization about change direction and intensity, which greatly extends the semantic meaning of the detected change targets.

Automatic GCP Extraction of Fully Polarimetric SAR Images

This paper presents a method for automatic extraction of ground control points (GCPs) of fully polarimetric synthetic aperture radar (SAR) (PolSAR) images obtained from various satellites with different viewing angles. The scale-invariant feature transform (SIFT) algorithm is applied to extract candidate GCPs, where two-way keypoint matching eliminates improbable correspondence keypoints. Minimizing the root-mean-square error (rmse) also removes matching points with large rmse through a pseudoaffine transformation. In addition, information entropy and spatial dispersion quality constraints enable quantification of the spatial distribution of the GCPs. In accordance with full polarization, applying the SIFT-OCT algorithm (SIFT algorithm with the first scale-space octave skipped) to PolSAR data is examined. The total power (TP) image represents a combination of the characteristics of all four polarization images [horizontal transmitting and horizontal receiving (HH), horizontal transmitting and vertical receiving (HV), vertical transmitting and horizontal receiving (VH), and vertical transmitting and vertical receiving (VV)]. Therefore, GCP extraction using a TP image rather than each polarization image is proposed in order to maximize the accuracy of GCP extraction for all of the polarization data, as the TP image generates the highest signal-to-noise ratio (SNR) value. The SNR in conjunction with the matching correlation surface is used as an indicator of the reliability and accuracy of GCP extraction. After successfully applying the method to Advanced Land Observing Satellite/Phased Array type L-band Synthetic Aperture Radar and Japanese Earth Resources Satellite-1 SAR images, the GCP matching accuracy is further improved by using geometric calibration.

Baekdusan Volcano Time-Series Analysis from 1992 to 1998 Using Multi-Interferogram InSAR Processing

A multi-temporal SAR interferometry (InSAR) method was applied to a time-series analysis of the period from 1992-1998 to detect precursor volcanic activity at Baekdusan volcano, located on the border between China and North Korea. Permanent scatterers were selected for stable signal processing to monitor ground motion using the permanent scatterer InSAR (PSIn-SAR) technique, which generated a time-series surface deformation map using the refined small baseline subset (SBAS) InSAR method. The time-series analysis results were verified using a multi-track comparison technique for two different tracks (88/230 and 89/230). The time-series analysis of the two tracks represents an unaltered phase signal (mm scale) with time, except for periods with insufficient interferograms to make a precise time-series surface deformation map due to factors including atmospheric phase delay and other error effects (i.e., those that display a maximum value of the phase difference from -2.14 to +2.64 cm). These phase signals also have the Root Mean Square Error (RMSE) range from 0.32-2.56 cm. No surface deformation was detected from the Japanese Earth Resources Satellites (JERS-1) synthetic aperture radar (SAR) data collected between 1992-1998 at the Baekdusan volcano, as monitored using volcanic surface movements with dynamic magma activity. No volcanic eruption precursor signals were demonstrated during the inactive period (1992-1998) prior to the active period (2002-2006) of this volcano.

Effects of Geopotential and Atmospheric Drag Effects on Frozen Orbits Using Nonsingular Variables

The concept of frozen orbit has been applied in space missions mainly for orbital tracking and control purposes. This type of orbit is important for orbit design because it is characterized by keeping the argument of perigee and eccentricity constant on average, so that, for a given latitude, the satellite always passes at the same altitude, benefiting the users through this regularity. Here, the system of nonlinear differential equations describing the motion is studied, and the effects of geopotential and atmospheric drag perturbations on frozen orbits are taken into account. Explicit analytical expressions for secular and long period perturbations terms are obtained for the eccentricity and the argument of perigee. The classical equations of Brouwer and Brouwer and Hori theories are used. Nonsingular variables approach is used, which allows obtaining more precise previsions for CBERS (China Brazil Earth Resources Satellite) satellites family and similar satellites (SPOT, Landsat, ERS, and IRS) orbital evolution.

SRTM vegetation removal and hydrodynamic modeling accuracy

[1] Hydrodynamic modeling of large remote forested floodplains, such as the Amazon, is hindered by the vegetation signal contained within Digital Elevation Models (DEMs) such as the Shuttle Radar Topography Mission (SRTM). Not removing the vegetation signal causes DEMs to be overelevated preventing the correct simulation of overbank inundation. Previous efforts to remove this vegetation signal have either not accounted for its spatial variability or relied upon single assumed error values. As a possible solution, a systematic approach to removing the vegetation signal which accounts for spatial variability using recently published estimates of global vegetation heights is proposed. The proposed approach is applied to a well-studied reach of the Amazon floodplain where previous hydrodynamic model applications were affected by the SRTM vegetation signal. Greatest improvements to hydrodynamic model accuracy were obtained by subtracting 50–60% of the vegetation height from the SRTM. The vegetation signal removal procedure improved the RMSE (Root-Mean-Square Error) accuracy of the hydrodynamic model than when using the original SRTM in three ways: (1) seasonal floodplain water elevation predictions against TOPEX/Poseidon observations improved from 6.61 to 1.84 m; (2) high water inundation extent prediction accuracy improved from 0.52 to 0.07 against a JERS (Japanese Earth Resources Satellite) observation; (3) low water inundation extent accuracy against a JERS observation improved from 0.22 to 0.12. The simple data requirements of this vegetation removal method enable it to be applied to any remote floodplain for which hydrodynamic model accuracy is hindered by vegetation present in the DEM.

Identification of Parasite-Host Habitats in Anxiang County, Hunan Province, China Based on Multi-Temporal China-Brazil Earth Resources Satellite (CBERS) Images

Remote sensing is a promising technique for monitoring the distribution and dynamics of various vector-borne diseases. In this study, we used the multi-temporal CBERS images, obtained free of charge, to predict the habitats of the snail Oncomelania hupensis, the sole intermediate host of schistosomiasis japonica, a snail-borne parasitic disease of considerable public health in China. Areas of suitable snail habitats were identified based on the normalized difference vegetation index (NDVI) and the normalized difference water index (NDWI), and the predictive model was tested against sites (snails present or absent) that were surveyed directly for O. hupensis. The model performed well (sensitivity and specificity were 63.64% and 78.09%, respectively), and with further development, we may provide an accurate, inexpensive tool for the broad-scale monitoring and control of schistosomiasis, and other similar vector-borne diseases.

Exterior orientation of CBERS-2B imagery using multi-feature control and orbital data

The major contribution of this paper relates to the practical advantages of combining Ground Control Points (GCPs), Ground Control Lines (GCLs) and orbital data to estimate the exterior orientation parameters of images collected by CBERS-2B (China–Brazil Earth Resources Satellite) HRC (High-resolution Camera) and CCD (High-resolution CCD Camera) sensors. Although the CBERS-2B is no longer operational, its images are still being used in Brazil, and the next generations of the CBERS satellite will have sensors with similar technical features, which motivates the study presented in this paper. The mathematical models that relate the object and image spaces are based on collinearity (for points) and coplanarity (for lines) conditions. These models were created in an in-house developed software package called TMS (Triangulation with Multiple Sensors) with multi-feature control (GCPs and GCLs). Experiments on a block of four CBERS-2B HRC images and on one CBERS-2B CCD image were performed using both models. It was observed that the combination of GCPs and GCLs provided better bundle block adjustment results than conventional bundle adjustment using only GCPs. The results also demonstrate the advantages of using primarily orbital data when the number of control entities is reduced.

DEVELOPING TROPICAL LANDSLIDE SUSCEPTIBILITY MAP USING DINSAR TECHNIQUE OF JERS-1 SAR DATA

Comprehensive information in natural disaster area is essential to prevent and mitigate people from further damage that might occur before and after such event. Mapping this area is one way to comprehend the situation when disaster strikes. Remote sensing data have been widely used along with GIS to create a susceptibility map. The objective of this study was to develop existing landslides susceptibility map by integrating optical satellite images of Landsat ETM and ASTER with Japanese Earth Resource Satellites (JERS-1) Synthetic Aperture Radar (SAR) data complemented by ground GPS and feature measurement into a Geographical Information Systems (GIS) platform. The study area was focused on a landslide event occurred on 26 March 2004 in Jeneberang Watershed of South Sulawesi, Indonesia. Change detection analysis was used to extract thematic information and the technique of Differential SAR Interferometry (DInSAR) was employed to detect slight surface displacement before the landslide event. The DInSAR processed images would be used to add as one weighted analysis factor in creating landslide susceptibility map. The result indicated that there was a slight movement of the slope prior to the event of landslide during the JERS-1 SAR data acquisition period of 1993-1998.
 Keywords: Optical Images, JERS-1 SAR, DInSAR, Tropical Landslide, GIS, Susceptibility Map
 1. Introduction
 Recently, natural disasters increased in terms of frequency, complexity, scope, and destructive capacity. They have been particularly severe during the last few years when the world has experienced several large-scale natural disasters such as the Indian Ocean earthquake and tsunami; floods and forest fires in Europe, India and China, and drought in Africa (Sassa, 2005). Mapping such natural disaster areas is essential to prevent and mitigate people from further damage that might occur before and after such event.
 In Indonesia in particular, in these recent years natural disasters occurred more frequently compared to the last decade (BNPB, 2008). Once within a month in 2011, in three different islands, Indonesia was stricken by earthquake, tsunami, flash floods, and volcanic eruptions with severe fatalities to the people and environment. It was obvious that Indonesia was prone to natural disaster due to its position of being squeezed geologically by three major world plates and this fact makes Indonesia one of the most dangerous

O futuro nebuloso da cooperação sino-brasileira na área de satélites

Successive delays in launching satellites CBERS-3 and CBERS-4, together with the lack of an agreement for the continuation of China-Brazil cooperation, generate uncertainty about the future of the China Brazil Earth Resources Satellites Program (CBERS).

CCD CBERS and ASTER data in dasometric characterization of Pinus radiata D. Don (North-western Spain)

A Chinese-Brazilian Earth Resources Satellite (CBERS) and an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) scenes coupled with ancillary georeferenced data and field survey were employed to examine the potential of the remote sensing data in stand basal area, volume and aboveground biomass assessment over large areas of Pinus radiata D. Don plantations in Northwestern Spain. Statistical analysis proved that the near infrared band and the shade fraction image showed significant correlation coefficients with all stand variables considered. Predictive models were accordingly selected and utilized to undertake the spatial distribution of stand variables in radiata stands delimited by the National Forestry Map. The study reinforces the potentiality of remote sensing techniques in a cost-effective assessment of forest systems.