Describes a system under development for the 3D fusion of multi-sensor surface surveillance imagery, including electro-optical (EO), IR, SAR, multispectral and hyperspectral sources. Our approach is founded on biologi...
详细信息
Describes a system under development for the 3D fusion of multi-sensor surface surveillance imagery, including electro-optical (EO), IR, SAR, multispectral and hyperspectral sources. Our approach is founded on biologically-inspired image processing algorithms. We have developed an image processing architecture enabling the unified interactive visualization of fused multi-sensor site data which utilizes a color image fusion algorithm based on retinal and cortical processing of color. We have also developed interactive Web-based tools for training neural network search agents that are capable of automatically scanning site data for the fused multi-sensor signatures of targets and/or surface features of interest. Each search agent is an interactively trained instance of a neural network model of cortical pattern recognition called a fuzzy ARTMAP. The utilization of 3D site models is central to our approach because it enables the accurate multi-platform image registration that is necessary for color image fusion and the designation, learning and searching for multi-sensor fused pixel signatures. Interactive stereo 3D viewing and fly-through tools enable efficient and intuitive site exploration and analysis. Web-based remote visualization and search agent training and utilization tools facilitate rapid, distributed and collaborative site exploitation and dissemination of results.
Some radar image processing algorithms such as shape-from-shading are particularly compute-intensive and time consuming. If, in addition, a data set to be processed is large, then it may make sense to perform the proc...
详细信息
Some radar image processing algorithms such as shape-from-shading are particularly compute-intensive and time consuming. If, in addition, a data set to be processed is large, then it may make sense to perform the processing of images on multiple workstations or parallel processing systems. We have implemented shape-from-shading, stereo matching, resampling, gridding and visualization of terrain models in such a manner that they execute either on parallel machines or on clusters of workstations. We were motivated by the large image data set from NASA's Magellan mission to planet Venus, but received additional inspiration from the European Union's Center for Earth Observation program (CEO) and Austria's MISSION initiative for distributed processing of remote sensing images on remote workstations, using publicly accessible algorithms. We have developed a multi-processor approach that we denote as CDIP for Concurrent and Distributed Image Processing. The speedup for image processing tasks increases nearly linearly with the number of processors, be they on a parallel machine or arranged in a cluster of distributed workstations. Our approach adds benefits for users of complex image processing algorithms: the efforts for code porting and code maintenance are reduced and the necessity for specialized parallel processing hardware is eliminated.
Signal based motion compensation (SBMC) is an enabling technology for low cost SAR applications as well as an enhancement for more robust SAR applications. SBMC involves down range and cross range compensation for pla...
详细信息
Signal based motion compensation (SBMC) is an enabling technology for low cost SAR applications as well as an enhancement for more robust SAR applications. SBMC involves down range and cross range compensation for platform motion with motion compensation signals derived entirely from radar signal based measurements. It is an alternative to motion measurement sensor (MMS)-based motion compensation and a next step growth from autofocus. A very robust SBMC algorithm has been developed and demonstrated on simulated data and real radardata provided by actual radars. The algorithm is tuned to a particular radar and adapted to any level of aircraft navigation system. This SBMC approach will enable a low cost SAR capability to be provided for budget minded applications. Alternately, it can also be applied to high performance SAR systems for improved capability. It will extend current MMS motion compensation and autofocus performance and provide a backup capability to compensate for navigation system performance degradation, such as from component failure or GPS jamming.
Space-time adaptive processing (STAP) techniques promise to offer the best means to detect weak targets in severe dynamic interference scenarios. Traditionally, STAP techniques were developed for the detection of low ...
详细信息
Space-time adaptive processing (STAP) techniques promise to offer the best means to detect weak targets in severe dynamic interference scenarios. Traditionally, STAP techniques were developed for the detection of low RCS, high velocity airborne targets, well removed from main-beam clutter in Doppler. STAP algorithms are only now being used for ground moving target indication (GMTI) from an airborne reconnaissance platform. We present a practical approach to STAP incorporating three components: nonhomogeneity detection, statistical processing of measured data, and hybrid processing. This combined approach ties together previous research in different aspects of STAP into one algorithm. The algorithm is tested using measured data from the Multi-Channel Airborne radar Measurements program with particular interest in ground moving target detection.
In the recent years synthetic aperture radar (SAR) technique and its application is much emphasized in the field of remote sensing. SAR sensor is being developed as a key geometric data source. This paper presents the...
详细信息
ISBN:
(纸本)078036435X
In the recent years synthetic aperture radar (SAR) technique and its application is much emphasized in the field of remote sensing. SAR sensor is being developed as a key geometric data source. This paper presents the main R and D activities of synthetic aperture radar systems in Institute of Electronics, Chinese Academy of Sciences (TECAS). It includes 5 parts of work on airborne SAR, spaceborne SAR, ground SAR processer, basic scientific and technical research and new generation's SAR technologies. These activities are explained and representative examples are described.
Summary form only given. Laser radars have the unique capacity to give intensity and full 3-D images of an object. Doppler lidar can give velocity and vibration characteristics of an object. These systems have many ci...
详细信息
ISBN:
(纸本)0780363191
Summary form only given. Laser radars have the unique capacity to give intensity and full 3-D images of an object. Doppler lidar can give velocity and vibration characteristics of an object. These systems have many civilian and military applications such as terrain modelling, depth sounding, object detection and classification as well as object positioning. There are several laser radar techniques under study using gated viewing, scanning lidars and 3-D sensing focal plane arrays and other scannerless lidar. During the study and experimental evaluation of these systems at FOA we have found it necessary to incorporate a good sensor model to be able to explain and foresee the performance of the system during different operating conditions. Examples of performance parameters are maximum range, range accuracy and range and transverse resolution. We give examples of signal waveforms generated from model different targets calculated by integrating the laser beam profile in space and time over the target including reflection characteristics during different speckle and turbulence conditions. Examples of experimental laser radardata are also given from different type of systems and applications and compared with the results obtained by using the modelled waveforms and receiver characteristic. The result is of help when designing and using new laser radar systems. The importance of different types of signal processing of the waveform in order to fulfil the performance goals is shown.
The control of the level of sugar cane in the chute feeding the shredder at the input of a sugar mill is an important parameter in determining the efficiency of the overall milling process. This paper describes the de...
详细信息
ISBN:
(纸本)078036435X
The control of the level of sugar cane in the chute feeding the shredder at the input of a sugar mill is an important parameter in determining the efficiency of the overall milling process. This paper describes the design and testing of an X-band frequency radar system built to measure the cane level in a shredder chute. This system uses a high gain horn antenna mounted inside the chute to illuminate the target area. The radar system measures distance using a modified, Frequency Stepped Continuous Wave (FSCW) technique. The measured data is processed to remove interference resulting from the finite isolation of the radar electronics and reflections from the aperture of the antenna. Testing of a prototype system shows that distance can be measured to an accuracy of about /spl plusmn/1 cm at a rate of 1 measurement per second.
Veridian ERIM International, with support from the US Air Force and the Defense Advanced Research Projects Agency Tactical technology Office (DARPA/TTO), has developed an airborne X-band SAR system capable of collecti...
详细信息
Veridian ERIM International, with support from the US Air Force and the Defense Advanced Research Projects Agency Tactical technology Office (DARPA/TTO), has developed an airborne X-band SAR system capable of collecting single-pass interferometric SAR data with cross-track baselines of 7.5 m, 15 m, and 30 m. SAR data have been collected over several sites with varying terrain and groundcover type. These data have been formed into 1-foot resolution imagery and interferometric processing has produced digital elevation data with post spacings of 1 m. The resulting elevation data have been compared with LIDAR elevation data in order to estimate the accuracy of the SAR elevation measurements. SAR elevation data with accuracy approaching the draft Level 5 specification for precision elevation data have been produced.
This paper presents the design of a high accuracy outdoor navigation system based on standard dead reckoning sensors and laser range and bearing information. The data validation problem is addressed using laser intens...
详细信息
This paper presents the design of a high accuracy outdoor navigation system based on standard dead reckoning sensors and laser range and bearing information. The data validation problem is addressed using laser intensity information. Beacon design aspect and location of landmarks are also discussed in relation to desired accuracy and required area of operation. The results are important for simultaneous localization and map building applications since the feature extraction and validation are resolved at the sensor level using laser intensity. This facilitates the use of additional natural landmarks to improve the accuracy of the localization algorithm. Experimental results in outdoor environments are also presented.
We propose a fuzzy inference based method to visualize the 3D structure of a tube buried in a concrete. The nondestructive testing (NDT) with pulse-radar, which makes it possible to non-destructively unmask the tubes ...
详细信息
ISBN:
(纸本)0769507506
We propose a fuzzy inference based method to visualize the 3D structure of a tube buried in a concrete. The nondestructive testing (NDT) with pulse-radar, which makes it possible to non-destructively unmask the tubes in a concrete, is one of the most remarkable techniques of NDT. However, only expert can interpret the scanned data. In our work, we represent such expert's knowledge with fuzzy if-then rules. First, the method estimates the candidate points of a tube on the scanned data. Next, 3D links of the candidate points are constructed by inferring the continuousness of the tube. Thus, this method can extract the internal structure of the concrete. Our experimental result expressed the 3D structure of tubes with high accuracy compared with the radiograph result.
暂无评论