Comprehensive data-reduction and analysis package for cloud and precipitation particle imager data.

An efficient, user-friendly, well documented data processing and analysis software package is needed to process the complex data produced by new airborne particle imaging probes, such as the SPEC 2D-S, cloud particle imager (CPI) and 3V-CPI probes. For example, the 3V-CPI, which combines features of the 2D-S and CPI, integrates data from the 2D-S probe plus images from a 1 Megapixel digital camera at 500 frames per second, amounting to a data rate exceeding 6 billion pixels per second. The very large data throughput and signal processing from these instruments require sophisticated and efficient software to process and interpret the collected data. Furthermore, software developed to process and analyze data from these probes must be standardized, user-friendly with clearly defined algorithms that are understood and available to the entire research community. SPEC Inc., the developer of the 2D-S and 3V-CPI probes, has already made significant inroads in the development of low-level code that analyzes the copious parameters associated with each particle imaged by the 2D-S and CPI probes. These low-level codes perform several functions, including decompressing images that have been compressed in hardware, analyzing several housekeeping and individual particle image signals, such as the particle arrival time, transit time, focus value, particle location on the array(s), deadtime in overload conditions, particle maximum length, width, area and perimeter, reject particles that are too closely spaced due to shattering on probe inlets, to name only a few examples. However, these codes have been written largely for the purpose of the company’s internal engineering evaluation of the performance of the probes. SPEC has also developed particle habit classification schemes for the standalone CPI. In Phase I, we will standardize and enhance the 2D-S codes to have straightforward point-and-click user interfaces and a first-cut technical manual. The final Phase I product will enable users of the 2D-S to select various community standard artifact rejection algorithms, display particle size distributions using selectable imaging processing techniques, compute derived parameters such as extinction, liquid and ice water content and effective particle radius. The CPI particle classification schemes and other candidate schemes will be evaluated for implementation in Phase II. The code developed in Phase I will output the particle size distributions and derived parameters in ascii format for input into archive files. The feasibility of commercializing the final software product will be evaluated. In Phase II, we will extend the software package to include data from the 3V-CPI, finalize the various software components and combine them into a user friendly, menu driven package with graphical displays. The package will be tested with real data and its functionality will be demonstrated. A plan for transitioning the package to commercial use will be developed.