Optical focal plane based on MEMS light lead-in for geometric camera calibration

Jin Li,Zilong Liu

doi:10.1038/micronano.2017.58

Abstract

The focal plane of a collimator used for the geometric calibration of an optical camera is a key element in the calibration process. The traditional focal plane of the collimator has only a single aperture light lead-in, resulting in a relatively unreliable calibration accuracy. Here we demonstrate a multi-aperture micro-electro-mechanical system (MEMS) light lead-in device that is located at the optical focal plane of the collimator used to calibrate the geometric distortion in cameras. Without additional volume or power consumption, the random errors of this calibration system are decreased by the multi-image matrix. With this new construction and a method for implementing the system, the reliability of high-accuracy calibration of optical cameras is guaranteed.

Highlights

High-accuracy determination of the position of features in the field of view is one of the most significant functions of a camera used on a satellite
An uncalibrated optical camera is placed on a precision turntable to capture the parallel rays of light of star points emitted by a collimator
We propose and evaluate a micro-electro-mechanical system light lead-in array device (MEMS-LLAD) composed of a porous silicon array; this system is located at the optical focal plane of the collimator used to calibrate an optical remote sensing camera

Summary

Introduction

High-accuracy determination of the position of features in the field of view (positioning) is one of the most significant functions of a camera used on a satellite. For a remote sensing camera, the main calibration method is based on measuring angles to known points to determine the principal distance and the principal point of the optics[15,16]. In this method, an uncalibrated optical camera is placed on a precision turntable to capture the parallel rays of light of star points emitted by a collimator. A least squares method is used to solve the imaging equations to calculate the principal distance and the location of the principal point In this method, a single-hole light lead-in (SHLL) is positioned at the focal plane of the collimator.

Methods

Results

Conclusion