Keeping connected on the road
In the rapidly evolving field of geospatial data collection, the accuracy and reliability of mobile mapping systems are paramount. This is particularly true in building-dense cities (called “urban canyons”) and on roads with a lot of tree canopy, where the challenges of maintaining an unobstructed and constant connection between the moving vehicle and satellites are amplified.
Just as in land surveying, a clear line of sight to the sky is crucial for precise mapping. However, mobile mapping systems equipped with a globally available positioning engine are designed to overcome these hurdles, ensuring that professionals in any geospatial field can achieve high-quality results both in the field and back at the office.
The evolution of GNSS and its role in mobile mapping
The origin of all satellite navigation systems is the Global Positioning System (GPS), which was introduced by the US Department of Defense in 1978 for both military and civilian use. Initially based on a constellation of 24 satellites, today GPS is part of a broader system known as GNSS (Global Navigation Satellite Systems), which includes other satellite constellations like GLONASS, Galileo and BeiDou. These additional constellations enhance the global coverage and accuracy of satellite navigation, a boon for mobile mapping technologies in use in remote locations.
Mobile mapping systems utilize these GNSS signals to pinpoint their exact location while in motion. By calculating the time it takes for signals from multiple satellites to reach the system's receiver, these systems can triangulate their position on Earth's surface. This capability is critical for collecting accurate geospatial data across vast areas in a short period.
Challenges faced by mobile mapping systems
Despite the advancements in GNSS technology, mobile mapping systems face similar challenges to those encountered in GNSS surveying. Obstructions such as buildings, bridges and trees can block or interfere with the direct line of sight to satellites, leading to potential errors in data collection. These errors can manifest as multipath errors, where signals bounce off surfaces before reaching the receiver, or atmospheric delays that distort signal timing.
Moreover, the dynamic nature of mobile mapping, often moving in and around obstructions at low and high speeds, introduces additional complexities in maintaining consistent and accurate GNSS connections.
For instance, when conducting a mobile mapping operation on a bustling urban freeway, the frequent changes in elevation from overpasses, bridges and tunnels, along with the proximity to large vehicles and skyscrapers, can significantly disrupt GNSS signals, challenging the system's ability to maintain a stable and precise location fix.
Overcoming obstacles with ProPoint technology
To address these challenges, Trimble® ProPoint® technology offers a robust solution for mobile mapping systems. ProPoint's advanced GNSS processing engine is designed to filter and utilize available signals effectively, even in the most demanding environments. Unlike traditional GNSS engines that require clean, unobstructed signals from multiple satellites, ProPoint can leverage individual signals from any constellation, significantly improving the reliability and accuracy of mobile mapping data collection.
In direct comparisons with previous-generation RTK engines, ProPoint has demonstrated superior performance in challenging conditions, including urban areas with high-rise buildings and under dense foliage. The technology has shown at least a 30% improvement in key metrics such as time to achieve centimeter-level precision, position accuracy, and measurement reliability.
For geospatial professionals, this means the ability to conduct mobile mapping operations in locations that were previously considered too challenging or too obstructed, without sacrificing accuracy or detail. Whether navigating through urban canyons or cruising along forested highways, Trimble MX90 mobile mapping systems, powered by ProPoint technology, ensure that data collection is not only possible, but also precise and dependable.
Embracing the future of mobile mapping
The integration of ProPoint technology into the Trimble MX90 mobile mapping system represents a significant leap forward in the field of geospatial data collection. By enhancing the ability to collect accurate data with better integrity at all speeds and in challenging environments, Trimble is empowering professionals to achieve more, faster and with greater confidence.
To learn more about the testing scenarios and the outcomes provided by advanced GNSS processing engines, download the white paper.