Tech Chat | How to test the accuracy of IMU?

In past blogs, we've introduced what IMU is and how it works on our Y1 GNSS receiver. Nowadays, more and more GNSS receivers integrate IMU module for greater convenience and higher efficiency. So to judge the performance of the IMU function become a focus. Today, we will introduce a conventional method of testing the accuracy of IMU, so that you can test your own equipment.

Preparation:

• GNSS receiver, here we will take Y1 as an example.
• Field surveying software, in this blog we will use SingularPad.
• PDA device.

Test Scene:

Here we will introduce several typical scenes, you can select one fixed point in each scene. If you have enough time or want to test in more detail, you can also set more points in one environment.

• Scene 1: Open sky
• Scene 2: Under the tree
• Scene 3: Near the building

IMU Test:

Before the test, you should make sure your GNSS receiver gets a fixed RTK solution and initialize the IMU function.

Related tutorials: 
SingularSurv Software Tutorial Video
Y1 Tutorial | Y1 GNSS Receiver IMU Calibration

Step 1: Turn off the IMU function and measure each test point while centering the pole. The point coordinates will be used as a reference.

Step 2: Turn on the IMU function, measure each point at different tilt angles and tilt directions.

• Tilt direction: East, west, north and south.
• Tilt direction: Y1 GNSS receiver support up to 60° tilt surveying, so we can choose several angles between 0 - 60° at an interval of 10°, which should be 0°, 10°, 20°, 30°, 40°, 50° and 60°.

Then we will get 16 sets of point coordinates for each test point.

Step 3: Compare the point coordinates of each test point with its reference, the error should be the accuracy of the IMU function. You can now see how the IMU accuracy varies with the tilt angle increasing and how horizontal accuracy and vertical accuracy clearly.

As shown in the picture above, the IMU error of our Y1 GNSS receiver is less than 3cm with up to 60° tilt surveying. Learn more about Y1:
https://www.singularxyz.com/Y1.html