SparkFun RTK mosaic-X5

Jargon buster

Plain-language definitions for the technical terms used above.

B1I

A BeiDou satellite signal used for standard positioning. It matters because the receiver must support the signal bands used by a constellation to take advantage of those satellites.

B2a

A BeiDou satellite signal used by newer dual-band GNSS receivers. Support for B2a can improve accuracy and reliability when combined with other GNSS bands.

CTS

CTS stands for Clear To Send, a serial flow-control signal that tells the other device it may transmit. It matters for reliable high-speed serial communication where buffers could otherwise overflow.

DC

DC means direct current, where electricity flows in one constant direction, as supplied by batteries, USB ports and many plug-pack power supplies. When a product specifies DC, it runs from a DC supply rather than mains AC, so you need to provide the correct voltage and polarity.

E1

A Galileo satellite signal band used for standard positioning. Knowing which signal bands are supported helps you judge compatibility and expected performance of a GNSS receiver.

E5a

A Galileo satellite signal band used for higher-performance positioning services. Support for E5a can help dual-band GNSS receivers improve accuracy and reduce errors from atmospheric delay.

EGNOS

Europe’s SBAS service for improving GNSS positioning accuracy and reliability. It is relevant if the receiver will be used in Europe or nearby supported areas without an RTK correction link.

ESP32

ESP32 is a family of low-cost microcontroller chips and modules from Espressif with built-in WiFi and Bluetooth. They support programmable firmware and over-the-air updates, and are commonly programmed with toolchains such as the Arduino core and ESP-IDF.

GAGAN

India’s SBAS service for improving GNSS positioning. It matters for projects in its coverage region because it can improve standard GNSS accuracy when RTK is not being used.

Galileo

Europe’s satellite navigation system. Galileo support can improve satellite availability and accuracy, especially when combined with GPS and other constellations.

GLONASS

Russia’s satellite navigation system. A receiver that can also use GLONASS has more satellites to choose from, which can improve positioning reliability when the sky view is partly blocked.

GNSS

GNSS stands for Global Navigation Satellite System, an umbrella term for satellite positioning networks such as GPS, GLONASS, Galileo and BeiDou. Receivers use these satellites to determine position, and high-precision units can output a steady stream of serial position data.

GPS

The US satellite navigation system used by GNSS receivers to calculate position and time. Support for GPS is important because it is widely available and often used together with other constellations for more reliable positioning.

L1C/A

A GPS signal band used by many GNSS receivers for standard positioning. Support for this band helps determine which satellite signals the receiver can use and how well it can maintain a location fix.

L2C

A second GPS signal band used by dual-band GNSS receivers to improve precision and reduce errors caused by the atmosphere. It matters for RTK and high-accuracy applications because using two bands can produce faster and more reliable centimetre-level fixes.

L5

A modern GNSS signal band used by several satellite systems for more accurate and robust positioning. Dual-band receivers that include L5 can often perform better than single-band receivers, especially for RTK and areas with reflected signals.

microSD card

A microSD card is a small removable flash memory card used to store data such as audio, images, logs or program files. Its capacity and formatting (often FAT32 or exFAT) affect how much can be stored and whether the card needs preparing before use.

MSAS

Japan’s SBAS service for improving GNSS positioning. It is useful to know because SBAS benefits depend on whether your project is located in the service’s coverage area.

OLED

OLED stands for organic light-emitting diode, a display type where each pixel produces its own light. It matters because OLED screens are thin, high-contrast and easy to read for small status displays, but they can be more sensitive to image burn-in than some other display types.

PoE

Power over Ethernet lets one Ethernet cable carry both network data and electrical power. This is useful when installing a device where running a separate power adaptor would be difficult.

ppm

ppm means parts per million, a common way to express very small gas concentrations in air. For CO₂ sensors, the ppm range tells you what levels the sensor can measure, such as normal indoor air through to poorly ventilated spaces.

QZSS

Japan’s regional satellite navigation system designed to improve coverage around Japan and the Asia-Pacific region. QZSS support can improve satellite availability in supported regions when used alongside GPS.

RTK

Real-Time Kinematic positioning is a GNSS technique that uses correction data from a base station to greatly improve location accuracy. It matters if you need centimetre-level positioning for robotics, mapping, surveying, or tracking rather than ordinary metre-level GPS accuracy.

RTS

RTS stands for Request To Send, a serial flow-control signal used to manage when a device is ready to receive data. It matters when moving fast serial streams because flow control can help prevent lost data.

RX

RX means receive, usually showing data being received by the board. An RX indicator LED can help with troubleshooting USB or serial communication.

SBAS

Satellite-Based Augmentation System, a set of regional services that broadcast correction information for GNSS receivers. SBAS can improve ordinary GPS-style positioning, although it is not the same as centimetre-level RTK correction.

SMA

SMA is a small threaded coaxial (RF) connector widely used to attach antennas and other radio-frequency cables. A device with SMA antenna ports needs antennas or pigtails with matching SMA connectors, or a suitable adapter, to connect to them.

TX

TX means transmit, usually showing data being sent from the board. A TX indicator LED can help you see when the board is communicating or uploading code.

UART

UART is a simple asynchronous serial interface that sends data over separate transmit and receive wires, usually labelled TX and RX, with both ends set to the same baud rate. It is a common way for microcontrollers and other serial devices to exchange data.

USB-C

USB-C is a small, reversible USB connector that can carry power, data and, on some devices, video over a single cable. The same connector can range from charging only to high-speed data, so the functions a given port actually supports vary.

WAAS

A North American SBAS service that provides correction data for GNSS receivers. It matters if you are using the product in a supported region and want better non-RTK positioning accuracy.