Day 1 - Pointing Error Metrics Workshop: Image Motion Optical Transfer Functions and Pointing Error Analysis
The NASA Engineering & Safety Center (NESC) GN&C Technical Discipline Team (TDT) is sponsoring a two-day Workshop on the important topic of pointing error metrics for spacecraft 2-D imaging instruments. The Workshop will consist of a total of 8 hours over a two-day period.
The purpose of this Workshop is to inform practicing GN&C engineers, system engineers, and payload instrument engineers of advanced methodologies for analyzing the pointing performance of spacecraft and writing unambiguous pointing requirements that are relevant to performance of optical payloads, especially payloads with stringent pointing stability and jitter requirements. Another purpose of this Workshop is to provide techniques that can help attitude control and spacecraft system engineers understand the relationship between the Optical Transfer Function (OTF) and pointing errors. In this Workshop, rigorous mathematical definitions of displacement, smear, and jitter will be presented, and smear and jitter metrics incorporating key elements of optical engineering will be derived.
As will be discussed in the Workshop, the imaging performance of an optical system is affected by smear and jitter, which streaks and blurs an image. An Image Motion Optical Transfer Function (IM-OTF) can be used to characterize the degradation of the image, which is a function of the smear and jitter. The OTF can be used to define pointing error metrics in time-domain representations and equivalent frequency-domain formulas in ways that are useful for design, analysis, verification, and performance specification of optical systems and pointing control systems.
It is anticipated that this Workshop will contribute to a widely-accepted and uniform means of requirements definition, validation, and verification. The advanced pointing error metrics and analysis methodology will be presented for interactive discussion in this Workshop for eventual consideration as a new set of GN&C best practices for jitter analysis.
