The invention discloses a load
reference measurement system and method based on two-dimensional
grating diffraction. The method comprises the following steps: designing a
layout geometric scheme of a collimation light path and key parameters of an imaging camera according to the measuring range and precision requirements of a load
reference measurement system; structural parameters of a two-dimensional circular hole
grating arranged at the front end of the imaging camera are designed according to the LED
light source parameters and the key parameters of the imaging camera; at the front end of the imaging camera, enabling the collimation light path to form multi-stage
diffraction light spots through a two-dimensional circular hole
grating, obtaining the equivalent center-of-
mass coordinates of the double light paths by adopting a multi-light-spot center-of-
mass averaging method, and calculating the propagation direction of each
light beam in an imaging coordinate
system based on the equivalent center-of-
mass coordinates; and in combination with a collimation light path
layout geometric scheme, a load reference under an imaging camera coordinate system is calculated through inversion. According to the invention, the influence of LED light direction fluctuation, imaging
noise and single
light spot positioning error on the measurement result can be effectively inhibited, and the on-
orbit high-precision measurement of the load reference is realized.