How does GPS + GLONASS perform in areas with high building density

Improved Satellite Visibility

- GLONASS satellites are located in different orbital planes than GPS, providing additional coverage.
- Having more satellites available from both systems increases the chances of maintaining a connection to at least 4 satellites, which is required for a position fix.
- This is especially beneficial in urban canyons and other areas with obstructed views of the sky.

Higher Elevation Angles

- GLONASS satellites tend to have higher elevation angles compared to GPS in high latitude regions.
- Higher elevation angles mean the satellites are less likely to be blocked by buildings and other obstacles.
- This improves signal reception and reduces multipath errors caused by reflections off nearby surfaces.

Faster Time to First Fix

- Using both GPS and GLONASS provides over 50 satellites, greatly improving the time to get an initial position fix.
- This is important when entering a challenging environment like a city center, as the receiver can quickly reacquire satellites.

Improved Accuracy

- Studies have shown that in high latitude regions, GLONASS can provide comparable or even better accuracy than GPS alone.
- Combining the two systems further enhances positioning accuracy, especially in urban areas with high building density.
- Typical accuracy improvements range from 2-5 meters compared to GPS-only.

In summary, the combination of GPS + GLONASS provides significant benefits in urban environments with challenging satellite visibility. More satellites, higher elevation angles, faster fixes, and improved accuracy make it the preferred choice for applications requiring reliable positioning in dense cities.