Based on the measurement of chlorophyll content in the period of wheat growing and yielding and the relationship analysis between the content of chlorophyll and the amount of wheat aphid, this paper presented the basis of plant physiology for wheat aphid disaster monitoring using remote sensing technologies. The correlation curves addressing the relation between the amount of wheat aphid and the wheat spectra were figured out by ground spectral testing in 1995, 1996 and 1998, which verified the feasibility of wheat aphid disaster monitoring according to the ratio vegetation index of wheat spectral reflection, namely RVI. An approach of decision making for the time to wheat aphid preventing and curing was also offered, that is, what ' s the RVI when the aphid amount was about 500 in 100 trunks of wheat.It resulted in the key technology presentation for wheat aphid disaster monitoring, especially the technique for deciding the best time for wheat aphid preventing and curing.
Remote sensing data has been widely used to forecast rice production.The ratio models and regression models of rice production forecasting were established using NOAA/AVHRR data in this paper.To establish these models , the rice potential planting area was extracted using geographic information system technique from digital landuse map. Then the normalized vegetation index and ratio vegetation index was calculated for different regions and counties using NOAA/AVHRR data.The method are used to estimate the early and late rice production in Zhejiang province of China in 1998 and 1999.The results are acceptable.It warranted that the extracted information form the rice potential planting area is belonging to the rice and not to any other vegetation. Since the GIS database is available, the method is easily applicable to any new NOAA/AVHRR images and guarantees the avoidance of errors.
Research about potential loss assessment models for seismic hazard is the main part of the loss
assessment decision support system about seismic hazard, including two following parts, that is database
of the potential loss and loss assessment of the seismic. This database supports vector form special charts,
sensor data in grid form, module data about digital topography and the statistic data in table form and also
supports the switch between vector form and grid form. The property data of this database is stored in
independent relational database table and maps its corresponding space unit.
This research used the Tangshan city as application test area and synthesized many kinds of aviation
and satellite sensor data ( 1976 through 1996), topography data, basic ground factors and statistic data
about society economy, which are based on database to identify the factors of potential loss in the seismic
hazard and to make sure the maximum probability of each factor, then to estimate the maximum possible
loss.
Potential loss assessment models for seismic hazard are based on the probability theory to identity the
activity of seismic hazards and the possible relations between those seismic hazards. So the assay and
assessment is made up mainly by following parts:(1) Identifying the potential calamity events; (2)
identifying all kinds of potential factors of calamity events; (3) confirming the maximum probability of
each factor; (4) estimating the loss of hazard.
Making potential loss assessment models for seismic hazard, the procedure includes: (1) building the
current status of this potential hazard and the algorithm for potential trend of this potential loss for the
future; (2) ameliorating or adjusting the assessing algorithm of factors; (3) controlling the data quality in
the process of calculating for mathematics models; (4) assessing data precision of the calculating result for
data models.
It is a significant technique method attempt to research the potential loss assessment models for
seismic hazard by taking the seismic in Tangshan city as an example and synthesizing application sensor
and ground information system in order to assess the maximum potential loss in the seismic area. Further
research of model testing is ongoing.
Land-use and land-cover change is one of important parts of global changes. With the
development of 3S techniques, using the RS, GIS and GPS to study land-use and land-cover change has
become a mature method. Based on the spatial sampling theory, this paper has designed a integrated field
sampling frame using 3S technology. This frame takes full advantage of province map, land-use/land-
cover 1 km×1 km grid data,land-use/land cover classification map, road network map and land-use/land
cover divisional map. The 1 km×1 km grid data derives from land-use/land-cover classification data, each
grid value equals to the maximal area percent of land-use/land-cover classification in this grid. It really
describes the spatial pattern of land-use/land-cover. The field sampling region will be chosen according to
the 1 km×1 km grid data and land-use/land cover classification map. Based on the road network and all of
other spatial information, for example TM image, the field sampling line and sampling points will be
produced. In this article, we design the field sampling line and sampling points map for land-use/land-
cover in Heilongjiang. Testified by outside sampling, it is a kind of economic and applied field sampling
frame.
Development of remote sensing technique has strongly related with studies of spectral feature of materials. According to tendencies based on between developments of spectral remote sensing and its geological application, this paper described the development and tendency of both basis and technique of discrimination for minerals and rocks. First of all, techniques of both the relationships between materials and spectra and the spectral physical models have been summarized and analyzed. So do developments of them. Secondly, the technique, the potential and the available of application for geology, which used multispectal and hyperspectral remote sensing data, have summarized and discussed. Finally, It is the most important to use spectral feature to extract geological genesis and to quantify the information of mineralization in geological remote sensing.
Synthetic aperture radar is an active coherent high resolution imaging system. The classical
imaging algorithms process the SAR received data by matched filter in two - dimensional frequency
domain, and get reconstructed SAR images. In classical imaging algorithms, Fast Fourier Transform is
used broadly. Because of the limited frequency domain support of the SAR systems, the system impulse
responses in the range and azimuth directions are sinc functions. And the SAR images have great dynamic
domain. The ratio of the returned power between the bright and the weak targets reached 50 dB, even
higher. The sidelobe of a bright point target can easily obscure and violate the mainlobe of weaker points.
So SAR images often demands sidelobe reduction. The conventional sidelobe reduction applies the fixed
weighting functions on the whole aperture data, and the conventional weighting approach have to
compromise between the degree of sidelobe reduction and imaging resolution. In this paper discusses two
adaptively sidelobe reduction algorithms, and compared their processing results with conventional sidelobe
reduction methods by the simulated data and the IECAS L-SAR system raw data.
This paper mainly discusses about secondary geometric rectification for the high resolution aero images using ERDAS software, in order to find some feasible methods of the secondary geometric rectification for all kinds of aero images. It emphasizes on the rationality, accuracy and practicability of these methods to collect points from maps,and acquires a new kind of rectification model named synthetic model to collect points ,which can be used to correct unconventional images. Moreover, this technique also adapts to secondary geometric rectification of all kinds of TM and SPOT satellites images, and improves the precision and efficiency of geometric rectification. Comparatively it is a kind of practical secondary geometric rectification model.
Area count is often met in application of remote sensing. This paper presents two methods of automatic area computation of blocks in classified remote sensing images. These two algorithms, named line scanning and point growth, are developed from methods of graph filling in computer graphics, lines canning transformation and seed filling. In following paragraphs, these two methods are analyzed in detail and comparison is made between these two algorithms. After that, conclusion is drawn that point growth is easy to realize and line scanning is easy to access a fast processing speed. At last a computation result is given.
Urban change detection that can provide plenty of information about land use and urban development is one of the important applications of change detection techniques. Aiming at the special use on urban environment, a change detection method of image differencing based on textural features is presented according to the characteristics of Synthetic Aperture Radar(SAR) image in this paper. The texture differencing change detection method substitutes textural features for gray information to represent the characteristics of images and gets urban change status through differencing change detection.The experimental result shows that a higher change detect accuracy can be obtained through the texture differencing method than through the traditional image differencing method based on gray level for most features, and an obvious improvement on detect performance also can be obtained through this new method.
This paper has introduced a popular method of combining map component with OOP language to
develop Geographic Information System. This method has fully exerted the advantage of showing and
processing geographic information with map component and the flexibility of the OOP. On the basis of the
commerce and service census in Shanghai, we have developed Shanghai Commercial Geographical
Information System (PC Version) adopting the ComGIS technology. This system is developed in the
Visual Basic 6.0 environment embedded with the component MapObjects 2.1 of ESRI. Besides those basic
GIS query and analysis function, this system has also been developed with the functions of the commercial
circle mapping, the automatic positioning of commercial spot and the concentration analysis of commercial
spots distribution, according to the character of the commercial management and analysis. This paper has
elaborated on the function design, interface design and development technology of the system and
summarizes its character.
The system was constructed supported by ArcView3.1, software of GIS, using water resource
information in Liaoning Province obtained by TM of Landsat. It can provide showing, query builder of
spatial and properties data of ground water, hydraulic engineering, underground water. For economizing
memory space ,we build a basic river database which is a dynamic connecting system in using. Functions of
abstraction Chinese properties information, clue of document layer, partly and integration showing and so
on were exploited using Avenue, program language of ArcView3.1. The system realized the display and
transfer of apr files. The system is an easily operated visual GIS system with Chinese interface. And it
supplied the using help, if having problems on operation, users may use contents or index to receive help
information.
