GNSS OEM Board: An Overview
An Original Equipment Manufacturer (OEM) GNSS board can be categorized in several different ways, according to different criteria, and choosing the right OEM board for your application will depend heavily on a number of factors. These factors include the intended use of the board, ease of integration, environment, performance, accuracy requirements, cost, expandability, and power consumption.
The following are some of the most common differentiating factors and implementations of an OEM board:
With the growing availability of satellite navigation systems, from GPS and GLONASS to Galileo and BeiDou, the OEM board has increasingly being equipped with multi-constellation receivers. The benefit of this, of course, lies in the more accurate measurements that result from these systems operating simultaneously and in conjunction with one another. A multi-constellation OEM board is able to access a larger number of available constellations. In urban environments especially, the number of satellites visible to the user will surely increase, allowing for a more accurate final position.
GNSS signals are allocated to different frequencies (e.g. L1 and L2 bands). An OEM receiver board with multi-frequency signal processing can benefit from the removal of frequency-dependent errors on the signals, thus improving the board accuracy. However, since boards are typically centered on one specific frequency, multi-frequency boards do often require additional hardware. Hardware must be replicated for the processing of each of the frequencies, and factors including cost, size, power consumption, performance, and signal/band filtering must be carefully considered.
Differential techniques are often employed in order to correct errors and inaccuracies in GNSS measurements. When an OEM board has access to correction information, it has the potential to improve solution accuracy, making it much more accurate than other boards. The most widely used differential techniques include Differential GNSS, Precise Point Positioning (PPP), and Real Time Kinematic (RTK).
Many GNSS manufacturers have development kits available to assist users in the integration of a GNSS OEM board into their design. These kits include several components, and often include pieces such as enclosures and power cables, to make the integration as seamless as possible.