STARE

STARE is a real-time software receiver for tracking and estimating positioning, navigation, and timing (PNT) measurements from live signals of fifth-generation (5G) New Radio (NR), long-term evolution (LTE), and narrowband internet of things (NB-IoT) terrestrial and non-terrestrial networks (NTNs), including those from low-Earth orbit (LEO) satellites. STARE can also track fully user-defined custom pilot patterns and orthogonal frequency division multiplexing (OFDM) grids, enabling the tracking of any arbitrary OFDM signal, such as Starlink, or even any non-OFDM signal, such as OneWeb. The estimated measurements include the code phase, carrier phase, Doppler frequency, signal-to-noise ratio (SNR), and carrier-to-noise density ratio (C/N0). Real-time operation is achieved by directly interfacing with an arbitrary software-defined radio (SDR), which allows for continuous signal processing without the need to record the signals. The receiver also features a post-processing mode for handling pre-recorded digital baseband signals without requiring an SDR. STARE can track 5G NR, LTE, NB-IoT, and custom OFDM waveforms through either tracking loops, employing closed-loop architecture to track code phase and carrier phase, or in snapshots, utilizing only algorithms of the acquisition stage. In addition, STARE supports direct recording of the digital baseband signal to a file, bypassing any signal processing. STARE is fully implemented in C++.