Corrections are given for cell imbalance in the design and analysis of twelve (12)-target identification (ID) perception tests. Such tests are an important tool in the development of the Night Vision and Electronic Sensors Directorate (NVESD) observer performance model used in NVThermIP to compare electro-optical systems. It is shown that the partitions of the 12-target set previously used in perception experiments exhibit statistically significant cell imbalance. Results from perception testing are used to determine the relative difficulty of identifying different images in the set. A program is presented to partition the set into lists that are balanced according to the collected observer data. The relative difficulty of image subsets is shown to be related to the best-fit V₅₀ values for the subsets. The results of past perception experiments are adjusted to account for cell imbalance using the subset V₅₀ terms. Under the proper conditions, the adjusted results are shown to better follow the TTP model for observer performance.

Date Published: 30 April 2007
PDF: 12 pages
Proc. SPIE 6543, Infrared Imaging Systems: Design, Analysis, Modeling, and Testing XVIII, 65430D (30 April 2007);

Published in SPIE Proceedings Vol. 6543:
Infrared Imaging Systems: Design, Analysis, Modeling, and Testing XVIII
Gerald C. Holst, Editor(s)