The Earth-observing Photonic Integrated Circuit (EPIC) instrument concept suite has been developed to enable extremely low cost and compact instrumentation for Earth science applications. The platform includes both a multispectral aerosol polarimeter (EPIC MAP) as well as a greenhouse gas spectrometer (EPIC GHG). The photonic sensors are novel interferometric imagers. Light is collected by millimeter-sized apertures (e.g., lenslets or micro-mirrors) on the device, which couple to waveguides in the photonic circuit, where signal phases and amplitudes are measured. When coupling into the device with waveguide-grating couplers the apertures are polarization selective. Pairs of apertures form interferometer baselines that sample spatial frequencies in two dimensions. Multiple baselines on the device are used for reconstructing images of the intensity distribution in the field of regard. Silicon nitride and lithium niobate structures are hybridized for a photonic device that is compact, low-noise, and stable. Here we describe two instrument concepts, detail models and methods for interferometric imaging, and provide status of the interferometric imager device development.