GB/T 39612-2020 in English

Aerial Equipment Configuration Specifications

The standard requires that the aerial camera must meet the following requirements: shutter speed ≥ 1/800s, field of view ≥ 27°, lens distortion ≤ 0.3 pixels. For the UAV platform, it is clearly required to have equidistant exposure control function and POS data recording capability.

Precision control system

Establish a three-level precision control network:
1) The measurement accuracy of image control points is required to be ≤1/5 of the ground point error in the plane (≤4cm for 1:500 map)
2) The error in the aerial triangulation encrypted plane is controlled in different levels according to the terrain type
3) The accuracy of the final result meets the requirements of GB 35650

Aerial photography plan formulation

It is recommended to give priority to IMU/GNSS assisted aerial photography, which can reduce the density of image control points by 50%. Aerial photography should avoid the following seasons:
• Snow accumulation period (November to March in the north)
• Cloud cover during the rainy season (June to August in the south)
• Strong reflective period (noon in desert areas)

Key points for quality control

1. Camera geometry calibration must be performed before aerial photography
2. Image control points should give priority to permanent land features
3. Use self-calibration regional block adjustment to eliminate systematic errors