AI 中文总结
本文提出基于杨氏条纹的校准方法，结合迭代逆问题与双曲线条纹模型，可实现高精度像素校准，为NASA HWO天体测量仪器在轨校准提供支撑，助力类地系外行星探测。
AI 中文摘要
通过天体测量类探测类地系外行星需要达到0.3 μas级别的质心定位精度，这对空间望远镜的焦平面几何结构提出了严格要求。NASA宜居世界天文台（HWO）拟议的组件AGATE焦平面仪器，旨在通过将CMOS探测器的像素内响应函数校准至50 μpix（220 nm）的精度来实现这一目标。本文提出一种基于杨氏条纹的校准方法，该方法源自JPL和IPAG所采用的技术，用于绘制探测器上的像素响应重心偏移图。使用Pyxalis GIGAPYX-4600 CMOS传感器，我们通过模拟和实验室测量证明：（1）在当前设置下，使用10000帧图像可达到5×10⁻⁶ pix的精度；（2）像素间电容串扰和条纹双曲线性分别是小尺度和大尺度下的主要误差来源；（3）提出一种结合双曲线条纹模型的迭代逆问题方法，以克服1 Gpix焦平面的近轴近似限制。这些结果为HWO天体测量仪器的在轨校准铺平了道路，确保了探测类地系外行星所需的亚μas精度。
英文摘要
The detection of Earth-like exoplanets via astrometry necessitates centroiding precision at the 0.3 microarcsec level, thereby imposing stringent constraints on the focal plane geometry of space telescopes. The AGATE focal plane instrument, a proposed component of the NASA Habitable Worlds Observatory (HWO), aims to achieve this objective through the calibration of the intra-pixel response function of CMOS detectors to an accuracy of 50 micropixel (220 nm The present paper proposes a Young's fringes-based calibration method, derived from those employed by JPL and IPAG, for the purpose of mapping the pixel response barycenter offsets across the detector. Using a Pyxalis GIGAPYX-4600 CMOS sensor, we demonstrate via simulations and laboratory measurements that (1) a precision of 500 micropixel is achievable with 10,000 frames (current setup); (2) inter-pixel capacitance crosstalk and fringe hyperbolicity are dominating the errors at small and large scales, respectively; and, (3) an iterative inverse problem approach with a hyperbolic fringe model is proposed to overcome paraxial approximation limits for 1 Gpix focal planes. These results pave the way for on-board calibration of HWO's astrometric instrument, ensuring the sub-microarcsec precision required for exo-Earth detection.
Journal refSPIE Astronomical Telescopes Instrumentation, Jul 2026, Copenhagen, Denmark
