First Use of the Binary Pseudo-Random Array (BPRA) in alignment and calibration of of  X-ray Photoemission Electron Microscopy

In this project, we explore the use of the binary pseudo-random array (BPRA) pattern to aid the microscope alignment and to improve the signal-to-noise ratio. BPRA is a useful calibration tool as displacement offsets between the physical array and the theoretical ground truth location can always be tracked. By calculating the displacement vector at each point, we can correct the distortion at each coordinate by adjusting the lenses. We compare the power spectral density (PSD) of the captured image of the physical BPRA and the PSD of the theoretical target. From there, we calculate the instrument transfer function (ITF), which quantifies frequency shift the instrument adds to the measurement. Then, we can use deconvolution and filtering to “deblur” the image and recover spatial resolution. See details from the poster below:

The following poster is presented at the 2026 Bay Area Light Sources Joint Users’ Meeting.