New Research Discovers Uneven Delays in Satellite Navigation Signals
Researchers at Shandong University of Science and Technology have made a significant breakthrough in understanding how tropospheric delays impact global navigation satellite systems (GNSS). Unlike previous studies that assumed isotropic or anisotropic characteristics, this research introduces the concept of non-isotropic Slant Path Delays (SPDs) based on azimuth angles.
by TAUHID SHAH: January 23: Tuesday: 21:36 PM| 2024 Updated.
GPS, GLONASS, and Galileo are important for many things, thanks to their accuracy. But sometimes, the Earth’s air called the troposphere, can make the signals from these satellites a bit late. People usually fix this by using something called Zenith Tropospheric Delay and some mapping tricks.
The research looked at three different ways of figuring out locations using satellites at International GNSS Service (IGS) stations. They compared how good these methods were by checking the numbers they gave with a really good method called ray tracing. What they found was that one of the methods, VMF3, was almost the same as ray-tracing. This suggests that VMF3 could make finding locations with satellites even better.
Surprisingly, the study also shows that fixing the way things slope sideways when looking at certain directions doesn’t make the accuracy much better. This goes against what we thought we knew about how delays work in the Earth’s atmosphere.
Dr. Ying Xu, the main researcher, says these discoveries are super important for making accurate GPS systems. If we know how delays change in different directions, we can make better models. This means GPS will be even more reliable when showing us where we are.
These discoveries matter a lot in areas like geodesy, where getting accurate measurements of Earth is super important. It also affects atmospheric sciences, like predicting the weather and understanding climate. The study suggests we need new ways of figuring out delays in the air so that things like GPS work better for navigation, travel, science, and defense.
