DarrenWong
commented
4 days ago Thank you for your interest in our dataset. We collect GNSS and IMU raw measurements from the SPAN-CPT and postprocess the data using state-of-the-art Inertial Explorer software from NovAtel, which maximizes the accuracy of the trajectory by processing forward and backward in time, performing a backward smoothing step, and combining the results.
Regarding your question "Can high-precision inertial navigation (another set of sensors besides IMU sensors) be used alone to obtain high-precision, long-term, and error free positioning results?"
Ans: We observed that our existing SPAN-CPT might not be good enough to provide long-term drift-free performance in super-dense urban or tunnel environments. However, it should be good enough to provide the GT in existing datasets. We also working on combining the measurements of SPAN-CPT and LiDAR/camera to achieve long-term and drift-free positioning results in urban areas. Please stay tuned!
For more details related to GT, you can refer to Section 3.1 of the Ubrannav paper
nothing371442
Hello, thank you very much for your work! May I ask why Novatel SPAN-CPT can still output centimeter level accuracy in high difficulty scenarios such as urban canyons? Have you done any post-processing work on Novatel SPAN-CPT output to optimize the ground truth? In my understanding, Novatel SPAN-CPT has high-precision inertial navigation and high-precision RTK, but high-precision RTK is not suitable for challenging scenarios. Can high-precision inertial navigation (another set of sensors besides IMU sensors) be used alone to obtain high-precision, long-term, and error free positioning results? thank you!