Inaccurate Newton's solution-based block adjustment method employing preconditioned conjugate gradient method

Abstract

The invention discloses an inaccurate Newton's solution-based block adjustment method employing a preconditioned conjugate gradient method. The preconditioned conjugate gradient method is introduced into a traditional block adjustment flow to solve a large-scale normal equation; and storage and direct inverse operation for the normal equation are avoided. According to the method, a normal equation coefficient matrix B is not directly stored while a matrix-vector product normal equation coefficient matrix Bd is calculated in a point-by-point manner; the block adjustment flow is suitable for a parallel design scheme; meanwhile, an accurate solution of the normal equation is replaced with an inaccurate Newton's solution, so that the number of iterations of the preconditioned conjugate gradient method is reduced; the memory capacity of data is reduced; and the determining speed of the overall block adjustment is improved.

Description

technical field [0001] The invention relates to the field of surveying and mapping science and technology, in particular to a preconditional conjugate gradient block network adjustment method based on an inaccurate Newton solution, which is mainly used in the fields of ultra-large-scale survey area photogrammetry and the like. Background technique [0002] After decades of development, block network adjustment technology has become relatively mature in its methods and processes, and has been widely used in the field of surveying and mapping. However, with the accelerated progress of science and technology, new sensors continue to emerge, such as high-resolution satellites in the aerospace field, three-dimensional mapping satellites, regular aerial photography systems in the aviation field, oblique aerial photography systems, drones, and airship photography systems. At the same time, the demand for 3D modeling applications around the world continues to increase, and a large n...

AI Technical Summary

Problems solved by technology

The increase in resolution will inevitably lead to an increase in the amount of data, and the route design during photography no longer satisfies the traditional strip-like regular distribution, which brings certain challenges to the corresponding data processing method. Limited by the size of the normal equation, The traditional block adjustment technical process can no longer meet the needs of large-scale data processing

Especially when the data size of the survey area exceeds 10,000 images, the traditional block adjustment method requires a sharp increase in memory. Even if there are a small number of graphics workstations with sufficient memory capacity, the large memory usage will greatly reduce the computational efficiency. , at the same time, the hardware cost of data processing also increases, the above problems all hinder the wide application of various new sensor data

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