Does it affect my survey? What is SBAS? What areas are covered with SBAS?
The orange (yellow) status LED indicates a steady but uncorrected GNSS signals, especially SBAS corrections, the most common and free source of GNSS corrections, received directly through the GNSS antenna.
What is SBAS?
The position of a GNSS receiver requires knowing, at each instant, the position and clock error for each GNSS satellite. This is performed through predicted values which are broadcasted by the GNSS signals through encoded messages. Such prediction parameters are in essence subject to inaccuracies that increase over time.
Satellite-Based Augmentation Systems (SBAS) help reduce these GNSS positioning errors by broadcasting, from a geostationnary satellite, more accurate sallite positions and clock drifts.
How will this affect my survey?
A static orange GNSS LED means that the system is waiting for GNSS corrections. However, it is ready to start acquisition without these corrections, which are not mandatory.
The only consequence of a orange status LED is that the real-time trajectory will be less accurate. This will be corrected during post-processing of the trajectory, so there's no loss in the final accuracy of the point cloud, usingthe sbet.
However, it must be taken into account, particularly when the triggering the camera module is determined by a height relative to the take-off point. If starting with orange status LED, then a margin must be added to reach this height (if you intend to fly at 80m , then set the initialization height at 75m, for example).
What areas are covered with SBAS?
Many countries and regions have implemented a Satellite-Based Augmentation System. EGNOS in the Europe, WAAS in the USA, GAGAN in India, MSAS in Japan, and KASS in South Korea, SPAN in Australia.
Outside of those areas, the Yellowscan systems start acquisition with the GNSS LED status in static yellow.
Some others are under development, like A-SBAS in Africa, SDCM in Russia and BDSBAS in Asia.
Follow the link below to check SBAS real-time availability:
EGNOS
WASS