Integrated Sensor Analysis Tool (I-SAT )

Transcription

1 FRONTIER TECHNOLOGY, INC. Advanced Technology for Superior Solutions. Integrated Sensor Analysis Tool (I-SAT ) Core Visualization Software Package Abstract As the technology behind the production of large array focal planes becomes more advanced and production costs decrease, the need for fast and accurate visualization and analysis software becomes more essential to demonstrate performance. Generic science data analysis programs are limited in their use of parallel processing and their ability to rapidly display high resolution imagery. Instead, intelligently designed, dynamic yet rapidly deployable software is the most capable and cost-effective solution. Frontier Technology, Inc. (FTI) has drawn on 30+ years of experience in the field of space-based sensor calibration to develop specialized software dedicated to efficiently viewing and reducing focal plane science data. FTI has designed a comprehensive visualization software package that is mission-tested in the arenas of requirements sell-off, customer presentation, and active test support. Introduction The Integrated Sensor Analysis Tool (I-SAT ) software is an optimized, sensor calibration and performance evaluation package that incorporates a proprietary data visualization component capable of storing and displaying multiple frames of NxM data where the actual dimensions of the data array are dictated solely by hardware constraints. The visualization component s load functions are parallelized for maximum speed with multicore processors and the display functions incorporate an intelligent decimation routine that

2 [Type text] Integrated Sensor Analysis Tool (I-SAT ) Software Package allows the analyst to view pixel arrays that may exceed the maximum screen resolution. The I-SAT software package was used in a recent mission to display frames larger than 16 million pixels, but can handle larger formats. Full, interactive control over display color scales, pan/zoom options, spatial/temporal/spectral line plots and histograms make the I- SAT package a dynamic and essential analysis tool. In addition to the visualization component itself, the I-SAT package is a fully-integrated, mission-tested calibration package that can be enhanced to utilize a MySQL database structured back-end. A tabbed interface allows the analyst to easily toggle between multiple pages, each dedicated to a specific capability. Available capabilities include: determination of focus; calculation of non-uniformity correction (linear/non-linear); pixel masking; peak detection; noise quantification; and data-frame comparison. Furthermore, the tabbed interface easily allows FTI to add custom mission-critical analysis capability. The I-SAT product is a fourth generation software package that is actively being used in the remote sensing calibration community. FPA Viewer The FPA Viewer tab is the primary interface of the I-SAT package and is shown in Figure 1. It consists of a large display component accompanied by an array of controls for manipulating and processing data. Raster formatted data can be loaded from files with the click of a button. Frames are stored internally and can be flipped through (slideshow style) or animated (movie style). This tab features many color scaling options including automatic and manual (fixed) scaling. Additionally, capabilities such as mouse-driven zooming, panning and intelligent decimation permit the user to view literally each pixel in a very large array. Array and window statistics are generated automatically to provide a quantitative understanding of the data. The data itself can be manipulated and corrected by applying offsets, non-uniformity corrections, non-linearity corrections, and/or bad pixel masks. Optional customization can be included to enable database-powered configuration management of a large set of data files. Collection parameters and other various meta-data can be associated with each file and used to generate specific constrained queries. These queries which can be constructed directly using the I-SAT package by the user return subsets of data that match the constraint. In this manner, the tool is an essential piece of

3 [Type text] Integrated Sensor Analysis Tool (I-SAT ) Software Package the overall data management solution and significantly reduces the amount of time wasted searching for files collected under any user-specified conditions. Figure 1: FPA Viewer Tab Interface

4 Line Plots The Line Plots tab shown in Figure 2 is a data-linked tab. Data loaded into the FPA Viewer tab is automatically loaded into the Line Plots tab interface. Data-linking tabs increases the utility of the tool because it enables the user to switch back and forth between tabs (and analysis options) without needing to reload data. The two line plot controls on the right side of the graphical user interface (GUI) display spatial swatches along the respective row and column of the pixel location selected. The third line plot control situated directly below the visualization component displays the pixel history through the frames. It plots the value of the pixel as a function of frame number and can provide insight into transient responses, noise processes and moving sources. Each line plot control features a 1-dimensional Gaussian fit routine to characterize point sources. Additionally, each plot possesses export options for both data (CSV, TXT) and image (BMP, PNG). Figure 2: Line Plots Tab Interface

5 Histograms The Histograms tab shown in Figure 3 is also data-linked to the FPA Viewer tab. Dedicated to the statistical properties of the data, this tab allows the user to select from either the full array or a sub-window of the array to generate a histogram. Display options such as the number of bins and logarithmic axes can be defined by the user to configure the histogram. This tab also features the ability to save histograms for on-screen comparison with manipulated or separately collected data. As with the other tabs, export options for both data and imagery are available to the user. Figure 3: Histogram Tab Interface

6 Frame Comparisons One of the most used tabs in the I-SAT package is the Frame Comparisons tab shown in Figure 4. This tab can load multiple data frames or files into side-by-side viewers for visual comparison. Additionally, it possesses the capability to perform pixel-by-pixel arithmetic and logical operations. For example, one frame can be subtracted from another and the pixel-by-pixel result is displayed in the visualization component at the lower right of the interface. In addition to this difference operation, other supported operations include: sum, product, difference, and bitwise logical comparison with a second frame. The user has the option of either loading that second frame from a file or using a tool-generated scalar frame (i.e. to subtract a constant offset or perform a 1/x inverse). Iterative analysis is also possible whereby the results from a pixel-by-pixel operation can be saved into memory and subjected to additional operations. This tab includes zoom capability, color scale options, and auto-generation of statistics. Lastly the resulting frame can be passed to the other tabs, at any point in the analysis. Thus, for instance, if the user needs to view the histogram or line plots from a ratio result one click passes the data to those tabs with no need for a file intermediary. Similar to the FPA Viewer tab, optional customization can be included to enable database-powered configuration management of data files. Figure 4: Frame Comparisons Tab Interface

7 Focus Measurements Focus is quite obviously a crucial element to any imaging program. Drawing from FTI s history in the space-based sensor community, the Focus Measurements tab calculates the energy-on-detector (EOD) from a point source of illumination. Data is passed through a proprietary iterative algorithm to calculate this measure of focus. The design of the EOD algorithm is such that it finds the sub-pixel center of intensity for every frame, and then uses the phasing information together with the measured counts to estimate the point response function (PRF) of the system. The additional elements of the solution (like semimajor, semi-minor widths, etc.) are used to generate contour plots of the solution an example of which is shown in the right-side visualization component in Figure 5. Additional through-focus analysis can be performed by collecting the EOD results of multiple collects at different stage positions, as shown in the secondary window of the figure. Figure 5: Focus Measurements Tab Interface

8 Non-Uniformity Correction A non-uniformity correction (NUC) is used to account for pixel-to-pixel variations in gain. These corrections can either be linear or non-linear. The NUC Generation tab as pictured in Figure 6 provides the user with the capability to generate and save correction frames to be used in other analyses to minimize or eliminate fixed pattern noise and correct pixel-to-pixel response characteristics. The NUC is one of the most important steps in a calibration. This tab provides the capability to generate Two-Point gain corrections, Linear Least Squares Fit gain/offset corrections, and Quadratic Least Squares Fit gain/offset correction. Files can be selected based on array statistics, telemetry value, or test ID. The corrections frame(s) themselves can be saved to file and configuration-controlled (if a customized database is being used). Figure 6: NUC Correction Tab Interface

9 Pixel Masking Large arrays commonly have a percentage of bad pixels. Characteristically, these pixels behavior is out of family in the sense that they are inoperative (dead), unresponsive or excessively noisy. To maintain the integrity of measurements made with the full array, these pixels need to be masked out. The Pixel Masking tab show in Figure 7 is used to generate a mask frame that can be applied during other analyses. Masks can be created by establishing thresholds on a number of statistical criteria including offset, gain, gainsquared, and/or noise. Additionally, pixels can be added to the mask according to a preestablished field-of-view (FOV) or manually by the user. As is true for the NUC Generation tab, the mask frame(s) themselves can be saved to file and configuration-controlled (if a customized database is being used). Figure 7: Pixel Masking Tab Interface

10 Future Capabilities New tabs are frequently being added to enhance the utility of the tool. Currently, a tab dedicated to quantifying focal plane noise is under development. Understanding the effects of fixed pattern noise and popcorn noise (among others) is crucial for verifying performance and effectively calibrating a focal plane. This new tab is being designed to perform this function and, when finished, will be an invaluable addition to the I-SAT package. Customization The I-SAT software package has been developed using a module-based approach to coding. As such, it is highly customizable. FTI has a long history of working with its customers to tailor software analysis packages to specific requirements. Examples of prior customizations include real-time calculation of focal plane statistics, support for extended source analysis, and full integration with a database-centric offline processing architecture. Conclusions FTI is committed to formulating efficient and cost-effective solutions to customer data visualization and analysis issues. The I-SAT software package is a product that has previously been implemented, validated, and appreciated by our customers. The I-SAT package has been instrumental in saving our customers time and money during testing and analysis on many of their data-intensive programs. We look forward to working with you to make your program a success!

11 About FTI Frontier Technology, Inc. is a small business that was founded in There are three groups within FTI: Decision Support Products and Services, Sensor Data Products and Services, and FTI Services. FTI s Phenomenology Operation within the Sensor Data Products and Services Group has unique expertise in sensor system analysis and performance evaluation, experiment development, and program planning, especially in the areas of sensor data certification, sensor systems calibration, sensor data management, optical remote sensing, and natural background phenomenology. For more information about FTI, please visit our website at or us at [email protected]. MySQL is a registered trademark of MySQL AB.