Why L2 GPS Frequency is Key to Accurate Drone Surveying

This article explains what the L2 GPS frequency is and why how it is related to accuracy. Even though L2 frequency is very important, many drone manufacturers do only use cheaper L1 receivers at the cost of inferior data quality.

GPS satellites transmit signals according to two carrier frequencies: L1 and L2. L1 frequency transmits information in the form of Course Acquisition (C/A) code, which is relatively straightforward and easy for receivers to collect and is thus meant for civilian use, i.e., general tracking and location services. L2 frequency transmits more complicated information in the form of Precise (P) code, which is to date used mostly by the military as it is precise and can be encrypted (then termed Y code). Receivers that can collect both L1 and L2 frequencies offer a great advantage to the user wishing for precise information, because the L2 frequency provides corrective data to the more course signal. Specifically, the L2 frequency combined with the L1 signal results in data that can remove ionospheric delay, making data much more precise. While this can be corrected for in the case of L1 frequency alone, it would require additional systems. Collecting both L1 and L2 presents a time and resource-saving advantage.