Accuracy Analysis of "Image-based Remote Target Micro Displacement Monitoring System Design and Implementation"

2.5 The main factors affecting system accuracy and reliability and their analysis

 

1. Atmospheric attenuation
   1. Impact: The signal intensity received by the CCD is lower than the minimum illumination limit, and the target and background cannot be distinguished
   2. solve:
      1. Use a laser at the wavelength of the atmospheric transmission window as the light source
      2. Select the appropriate light source power through the power budget, so that the laser energy emitted from the target can still be used after a large attenuation
2. Atmospheric turbulence
   1. Impact: There is a random drift in the center position of the target every time in the image
   2. solve:
      1. Collect multiple images to average
3. Shooting environment
   1. Impact: day/night; sunny/rainy
   2. solve:
      1. Establish high-precision reference targets in non-measurement areas
4. System component accuracy
   1. influences:
      1. The resolving power of the imaging system, the distance between the two object points at the imaging system L must be greater than ΔS to be resolved, and if it is less than ΔS, it will be regarded as the same object point
      2. CCD resolution accuracy: this article believes that it cannot be less than one pixel
      3. Theodolite angle measurement accuracy
      4. Stepper motor rotation accuracy: The multi-point measurement in this article uses stepper motor rotation
   2. solve:
      1. Target positioning error correction algorithm: using theodolite and stepper motor
      2. Spot subdivision algorithm: Find the center of gravity of the spot according to the gray distribution of the bright spot