Pandeia 3D exposure time calculator compute engine
Pandeia is a general framework, data-driven ETC capable of supporting multiple missions. The Pandeia ETC engine uses a pixel-based three-dimensional approach to perform calculations on small (typically a few arcseconds) two dimensional user-created astronomical scenes. It models both the spatial and the wavelength dimensions, using realistic point spread functions (produced using WebbPSF) for each instrument mode. It natively handles correlated read noise, inter-pixel capacitance, and soft and hard saturation. Since the signal and noise are modeled for individual detector pixels, Pandeia is able to replicate many of the steps that observers will perform when calibrating and reducing their data. This simplifies interpretation of the extracted signal to noise ratio (SNR) calculated by Pandeia. While Pandeia includes many effects not typically included in other ETCs, it is not an observation simulator. It does not simulate the full detector, nor does it include two-dimensional effects such as distortion. Details on the algorithms used to compute signal and noise on the detector and the strategies used to compute the extracted products can be found in “Pontoppidan et al. 2016”.