α7000（top-configuration）
<1>Using carbon fiber military materials：More stable, thermal shock resistance,low thermal deformation coefficient;
<2>Encoding calibration technology：this technology a total of 13 steps for reducing errors;
<3>Heterodyne multiple frequency：cast symmetrical stripes;
<4>It can be compatible with 3D photogrammetry system: This method will improve the measurement precision;
<5>Calibration source made.