Hyperspectral target detection has irreplaceable advantages which can identify meticulous spectral characteristic difference between the target and background. At present, the rapid development of high spaial and hyperspectral remote sensing provides more data for target detection. Target detection accuracy is closely related to target size、spatial resolution、spectral resolution、band settings、spectral characteristics of the target and background, detection algorithms. Generally, with regard to specifically target and background, the finer the resolution is, the higher the accuracy will be. Yet the spatial and spectral resolution can barely meet the need simultaneously, for technical obstacles. A tradeoff between the two factors is needed for effective target detection and the choice of appropriate remotely sensed data for target detection has always been concentrated nowadays.
To address this concern, this paper researched on target detection mechanism, evaluated the suitability of different detection algorithms. On this basis, this paper using ground hyperspectral sensor FISS (Field Imaging Spectrometer System) data and aerial hyperspectral AVIRIS data，studied on the situations where the target was small and had a similar spectrum to the homogenously distributed or complex backgrounds. Through the down sampling processing of the high spatial hyperspectral images, the paper analyzed the relationship between the spatial and spectral resolution and the detection accuracy. And then it proposed the optimal spatial and spectral scale for target detection. This study focused on the quantification of the scale impact of spectral and spatial resolution on target detection precision. Results revealed that：
(i) RXD algorithm is applicable to small and outstanding targets, anomaly detection algorithm has a higher false alarm rate comparing to other algorithms which have prior knowledges; CEM can achieve high detection accuracy in the case of small targets; ACE algorithm can be used to homogenously distributed background which can be represented by multivariate normal distribution；OSP algorithm is sensitive to the input spectrals of the background, the results may be affected in the complex background.
(ii) With the decline of spatial resolution, the pure target to be detected turned into sub-pixel, the detection accuracy experienced three stages of descending rates: gently-dramatically-gently. The radio of the target size and the spatial resolution has positive correlation to detection accuracy. The corresponding spatial resolution before the second stage is the effective scale for detection. In the ground experiment, the required spatial resolution for camouflaged detection was about within twice the size of the target. Using AVIRIS data, the required spatial resolution for aircraft detection was also about twice the size of the target.
(iii) Suitable spectral scale is related to the spectral difference between the target and the background (significant reflection peaks distance). In the ground experiment, the reflection peaks differences, associated with the target and the background, were 20nm apart. When the spectral resolution was coarser than 40 nm, the differences of reflection peaks disappeared and the detection accuracy decreased. Using AVIRIS data, since the reflection peaks differences were 200 nm apart, the detection accuracy was essentially the same when the spectral resolution ranging from 10-60 nm.
(iv) In the appropriate range of spectral scales, the spatial resolution plays an more important role in detection accuracy. In the ground experiment, the detection accuracy changed little when the spatial resolution remained the same and the spectral resolution varied from 10 to 40 nm. However, when the the spatial resolution decreased, the accuracy had a clearly decline. The aircraft detection had the same result.
(v) To select the quite different characteristic bands or abandon the similar bands from the target and background spectral can improve the detection accuracy. Refer to the multispectral sensors, the accuracy increased when we got rid of similar bands(430 nm) in the ground experiment, and the optimal combination bands were 450-510 nm, 510-580 nm, 585-625 nm, 630-690 nm, 705-745 nm. In the aircraft detection experiment, the optimal combination bands were 450-510 nm, 510-580 nm, 630-690 nm, 770-895 nm, 2235-2285 nm, 2305-2365 nm, according to the OIF(Optimum Index Factor). In addition, removing 1200-1700 nm bands can improve the detection accuracy due to the variability of the target.
It was concluded that the quantitative analysis method and results of spatial and spectral scales for target detection would be of great significance for both data source selection and studing on other target-background combinations under similar conditions.
With the continuous development of mineral exploration technology, the surface mineral exploration work became more and more difficult. The main direction of the mineral investigation is toward the underground. Core as the final link in mineral exploration keep the records of vertical change geological information. Without undermining core surface and destroying the core integrity, remote sensing as a new technology have macroscopical, fast and informative advantages. It is an indispensable means of geological prospecting. Hyperspectral remote sensing technology has the ability to identify the different minerals and composition according to the different minerals have different spectrum feature. Geological experts can use remote sensing geological information to analysis the geological metallogenic conditions, find prospecting areas and delineate target goals which providing good information to carry out detailed geological work.
The goal of this paper is design the core imaging spectrometer data catalog system including the interface and system function design. Firstly, in the condition of full consideration of the needs of users, the core catalog need stable, efficient, accurate, etc. This paper make a detail design on the core imaging spectrometer catalog system. Also this paper explore the spectral characteristics of rocks and minerals and study the key technologies of mineral identification. Then this paper work on the detailed design of the core imaging spectrometer system catalog fully considering three aspects: user habits, convenient and elegant interface master the software. The main results and conclusions are as follows:
1. Analyzed and summarized the common spectral characteristics of altered minerals. On the knowledge of various mineral spectral information, this paper studied the hyperspectral data extraction methods, such as the minimum distance matching, spectral angle matching, spectral absorption index etc.; Evaluated the spectral quality of core imaging spectral data using these methods, and investigated the accuracy of spectral matching technique. Quantified the spectral characteristics of minerals and used the mathematical methods in calculations to achieve unknown targets. Solved the core mineral identification problem, rapidly realized the translation and analysis of core information.
2. Based on the analysis and summarize the spectral characteristics of common alteration minerals, this paper explore the spectral information enhancement and various mineral extraction methods, such as spectral derivative, envelope removal, the minimum distance matching, spectral angle matching and spectral absorption index. Using those methods to make comprehensive statistical analysis of imaging spectrometer data core, the spectral characteristics can be quantified with the method of mathematical calculations to achieve the goal of determining the unknown targets. It solve the identified problems of the mineral core and achieve quick deciphering and analysis.
3. This paper amply design the interface and function modules of the core imaging spectrometer catalog system. The interface is divided into six part menu bar, toolbar, drilling display window, core catalog window, mathematical analysis window and parameter setting window. And design detailed function of each part to meet the basic need of each catalog functions. Also the interface strive to reasonably arrange space and make beautiful interface. From the user point of view the function module was design to automatically catalog to achieve the function of import of data, automatic cutting, automatic interpretation and editing and other geological data.