Passive imaging through optical obscurants is a promising application for mm-wave sensing. We have thus developed the Superconducting Kinetic Inductance Passive Radiometer (SKIPR), a 150 GHz polarization-sensitive photometric camera optimized for terrestrial imaging using a focal plane array with 3,840 kinetic inductance detectors (KIDs). We present a full description of the instrument design, with a particular emphasis on the cryogenic system based on a Gifford-McMahon cryocooler with a two-stage Adiabatic Demagnetization Refrigerator and a dedicated 1.59 m crossed Dragone telescope with an altitude/azimuth mount. We include a detailed lab-based characterization of the KIDs, which results in a determination of their superconducting resonator parameters and optical properties. We also present in situ measurements from the telescope, including point-spread functions and noise characterization. In sum, we find that SKIPR performs as expected, providing diffraction-limited imaging with detector noise performance set by the random arrivals of photons from the ambient background. There is minimal variation in detector characteristics over the full SKIPR focal plane array, and the overall detector yield is 92 per cent.
@article{arxiv.2502.14607,
title = {A Millimeter-Wave Photometric Camera for Long-Range Imaging Through Optical Obscurants Using Kinetic Inductance Detectors},
author = {Jack Sayers and Daniel Cunnane and Sage Crystian and Peter K. Day and Fabien Defrance and Byeong Ho Eom and Jonathan Greenfield and Matthew Hollister and Bradley R. Johnson and Henry G. LeDuc and Philip Mauskopf and Nia McNichols and Cody Roberson and Marcus C. Runyan and Adhitya B. Sriram and Sage Stanton and Ryan C. Stephenson and Liam C. Walters and Eric Weeks},
journal= {arXiv preprint arXiv:2502.14607},
year = {2025}
}