（1) Finding the Earth's Plane:
After entering the system, the system is initialized first. After the initialization is completed, the real-time image of the camera will be planar fitted by the system. When the picture shows the current road plane, the operation of finding the ground plane is completed.
（2) Drawing datum line:
Click on the drawing datum tool to align the screen alignment with the actual datum line position at the accident scene, click on the screen to complete one point acquisition of the datum line, and then click on the second point to complete the drawing of the datum line.
（3) Drawing datum points:
Click the Drawing Datum Tool to align the screen alignment to the location of the datum point at the accident scene, and click the screen to complete the drawing of the datum point.
（4) Drawing location points:
Click on the drawing datum tool, align the screen alignment to the location of the accident scene (wheels, etc.), and click on the screen to complete the datum drawing.
（5) Delete:
Align the screen alignment to the already drawn positioning point, click the screen, the positioning point will jump, click the delete button to complete the deletion of the positioning point.
（6) Photography:
Aim the lens at the scene of the accident, ensure that all elements such as drawing are included, and click the Photo button to complete the measurement.
（7) Reset:
The system can't find the ground plane for a long time or to redraw it, you can click the reset button.
IPAD Tablet Laptop
Operating system:IOS 7.1; Processor: A9 chip has 64-bit architecture and M7 motion coprocessor, storage capacity: 32GB; display screen size: 9.7 inches; screen resolution: 2048 x 1536; screen description: capacitive touch screen, multi-touch screen; referring device: touch screen;
Laser range finder
Video Viewing, Wireless Bluetooth Function, Measurement Accuracy+/- 1.0mm +/-0.3° measurement range 0.05m-200m; maximum/minimum measurement function; add/subtract function; area/volume calculation function; indirect measurement (Pythagorean theorem); timer function/continuous measurement function; measurement range +/-50° in tilt sensor has trapezoidal measurement function; the last 20 are invoked. Measurement value; 4 times digital sighting function; tripod threads; backlight display/multi-function base; splash-proof/dust-proof IP54 function; each battery can measure at least 5,000 times;
Accident scenePhotogrammetry SystemSoftware module
The system conforms to the new national standardGA49-2014 requires that it has the function of real scene drawing and can be transformed from real scene to scale map. Data can be automatically generated by ranging scale. In large-scale accident scene, multiple photographs can be taken, and the position of datum point and datum line can be marked in the real scene photographs, and the related photographs can be transformed into the scene map at the same time.