Glossary
Plain-language definitions for terms used throughout the LEO100 documentation. Use this page as a reference whenever a term in the Setup Journey or a tutorial is unfamiliar.
A
Almanac. A coarse, long-validity set of orbital parameters for all satellites in a GNSS constellation. Used alongside the Ephemeris for warm starts to reduce time-to-first-fix.
B
.bin file. The default file extension for raw RF (and optionally IMU) recordings produced by the RadioLion. Replayable through PpRx for post-processing. See the Record RF Data tutorial.
C
C/N0. Carrier-to-noise-density ratio, in dB-Hz. A standard measure of received GNSS signal quality. Visible in the GUI's C/N0 plot during a PpRx run.
CLI. Command-line interface. PpRx, the RadioLion device nodes, and supporting tooling can all be driven from a terminal. See the Advanced Tutorials for CLI-only workflows.
Cold start. A PpRx run started with no prior knowledge of satellite positions or time. Time-to-first-fix is typically around 30 seconds in good RF environments. Compare to warm start.
.config file. The PpRx configuration file. Controls receiver internals: acquisition, tracking-loop, and estimator tuning. Generated by the Configuration Generator during the Beginner Tutorials (Phase 3).
D
DSP. Digital signal processing. PpRx performs all of its GNSS receiver work, including acquisition and tracking, as software DSP on the host CPU.
E
Ephemeris. A precise, short-validity set of orbital parameters for a specific satellite. Required to compute that satellite's position when generating a PNT solution. Preloading ephemerides enables warm start.
G
GBX. Locus Lock's binary serialization format for PpRx and PpEngine outputs (reports, observables, ephemerides, etc.). The wire format you'll most often parse from middleware. See the GBX Protocol Description.
GenericType. A signal-identifier field used inside GBX, .log, and .mat files. Mapped to specific GNSS signals via the GenericType Mapping table.
GNSS. Global Navigation Satellite System. The umbrella term for all satellite positioning constellations (GPS, Galileo, GLONASS, BeiDou, etc.).
GUI. Graphical User Interface: the graphical application for configuring, running, and observing PpRx. Recommended starting point before moving to CLI-only workflows.
H
Host computer. The machine on which PpRx and the Locus Lock GUI run. LEO100 can be purchased with or without a Locus Lock-supplied host. Minimum specs are listed on the Software Installation page.
I
IMU. Inertial measurement unit. The RadioLion exposes an IMU data stream on a second /dev/radiolion* device node. Recording IMU data is optional and unnecessary for most users.
I/O Overlay. The Input/Output panel in the GUI where PpRx's data sources and outputs are configured. Introduced in the Configure PpRx in the GUI tutorial.
L
L1, L2, L5. GNSS frequency bands. The RadioLion is a triple-frequency front end and conditions all three.
LEO100. The full Locus Lock turnkey PNT solution. Includes PpRx, the RadioLion RF front end, and the Locus Lock GUI. See Introduction for variant details.
M
Middleware. Any code that sits between PpRx's outputs and your target application. Typically a parser or wrapper for GBX, NMEA, or other configured output streams.
N
NMEA. National Marine Electronics Association. A standard ASCII protocol for GNSS position and timing messages. One of several output formats PpRx can produce. The PpRx output follows NMEA 0183. See Configure PpRx Outputs in the GUI.
NTP. Network Time Protocol. PpRx allows your host system to act as a Stratum 1 GNSS-Disiplined NTP server to discipline the host clock.
O
.opt file. The PpRx options file. Controls I/O: which devices and files PpRx reads, which outputs it writes, and where. Generated by the Configuration Generator during the Beginner Tutorials (Phase 3).
P
PNT. Position, Navigation, and Timing. The class of solution LEO100 produces.
Post-processing. Running PpRx against a previously recorded .bin file rather than a live RadioLion stream. The default workflow for repeatable testing.
PpEngine. Locus Lock's precise positioning engine. Runs alongside PpRx and consumes its observables to produce RTK, integrate external sensors and provide precision heading solutions. Required for dual-antenna heading workflows..
PpRx. Locus Lock's software-defined GNSS receiver. Processes raw RF samples from the RadioLion and produces a PNT solution plus configurable outputs.
R
RadioLion. Locus Lock's RF front end. Triple-frequency (L1/L2/L5), available in single- or dual-antenna configurations. Exposes two Linux device nodes when connected: a lower-enumeration RF stream and a higher-enumeration IMU stream.
RF. Radio frequency. The raw signal class the RadioLion conditions and digitizes before handing samples to PpRx.
RINEX. Receiver Independent Exchange Format. A standard text format for GNSS observables and navigation data. One of PpRx's optional output formats.
RRT. Raw Receiver Time. The time since the start of a PpRx run, shown in the GUI's bottom information bar.
RTK. Real-Time Kinematic positioning. A technique that uses carrier-phase observables and a reference station to achieve centimeter-level accuracy. Provided by PpEngine on eligible variants.
S
Simulate Realtime. A PpRx post-processing option that throttles .bin playback to wall-clock speed, mimicking a live run.
T
TTFF. Time to first fix. The interval between PpRx starting and producing its first valid PNT solution. Reduced by warm start.
W
Warm start. A PpRx run that begins with preloaded ephemeris and almanac data, reducing TTFF compared to a cold start. See Warm Start PpRx.