Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [gnss]

Satellite navigation systems, including GPS. Questions should be related either to amateur radio operations (e.g. APRS tracking) or the theory of positioning using radio signals; questions merely about using GPS receivers are not on-topic.

GNSS or "global navigation satellite system" is the generic term for a collection of satellites that may be used for determining position. The most well known system, whose name is often used interchangeably for it and the technology in general, is the United States' Global Positioning System (GPS).

In amateur radio, the most common use of GNSS / GPS technology is to report the location of a station over . It may also be used to obtain accurate time information to coordinate operations between stations, such as agreed-upon transmission times or locating a transmitter by precisely measuring the time of reception at multiple receivers.

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How do GPS receivers communicate with satellites?

I have a Technical Amateur Radio license so I know the basics of wavelengths. What I'm researching is how GPS works. From what I've read, there are frequencies such as L1, L2, and L5 uses in GPS between the receiver and the satellite. These operate…
john_ham_radio
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Can every antenna be used both for transmit and receive?

Assuming I have an antenna for receiving GPS signals, can I use it also for transmit — to create a repeater in a tunnel (or some place with no reception)?
volatile
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Use ham to broadcast GPS RTK correction data

I am involved in a precise positioning project that uses Real Time Kinematic (RTK) for cm-accurate positioning. We use unattended base stations that provide real-time corrections for mobile rovers. The corrections can be used within a radius of…
Kozuch
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How do I connect a GPS receiver to a radio for APRS?

I volunteer with the local search and rescue group as a team medic and a radio operator. The team is new and recently decided to go with the Garmin 64st as our go-to GPS units. Those of us with licenses use the cheaper Baofeng UV-5R and BF-8HP…
john.weland
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Using a flip-phones GPS NMEA data for the GPS in an APRS station

I have heard that it is possible to connect certain flip-phones to external devices via their Micro USB port and, through the USB port, send the NMEA location Data from their internal GPS to an external device. I am wondering if it would be possible…
W8AWT
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Generally, what happens when you power a GPS antenna or other RF amplifier with a low voltage?

I have a 5V active GPS antenna, and want to try using it on a device with a 3.3V bias provided. Obviously, operating at an over-voltage can damage or destroy the LNA. But what happens when the voltage is too low? Will it work with reduced gain,…
Paul
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How to read ID-51A GPS logger data

I own the original Icom ID-51A. I have the GPS logger logging every 5 seconds to the microSD card. How do I view this saved track data on my computer? For reference, here's one of my logs (I know it looks like I'm going in circles, I was doing…
Daniel
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Why some QO-100 setups use GNSS

I'm looking into building a QO-100 setup, but am struggling to find good/easy to understand resources for beginners which would outline the most common approaches and their pros/cons. From what I could gather, there seem to be two main…
Tadej Gašparovič
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Will two GPSDO units be precisely in phase with each other?

I always thought of a GPSDO as only a precise frequency reference. But the GPS and other GNSS systems also deal with rather precise UTC/TAI-ish time! Are the outputs of any two GPSDO units generally designed/expected to provide the same phase…
natevw - AF7TB
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Why do watches with GPS receivers have an "airplane mode"?

I noticed that watches with GPS signal receivers made by Seiko and Citizen have an airplane mode. If it's a GPS receiver, it shouldn't cause interference, right?
neuhaus
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Is it possible to transmit telemetry data (GPS) via QRP?

I have a GPS tracking device which was designed for inventory management, currently I'm using a GSM module to transmit the telemetry data (latitude and longitude only) to the base station. The problem in using GSM is it is not suitable to work in…
Sumithran
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What equipment and software do I need to read raw civilian GPS signals on my Mac?

This is a hobby project to learn more about GPS technology.
Ali Gajani
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Total cancellation in corporate feed network for patch antenna

I'm trying to build an array of patch antennas in order to receive a GPS signal. The idea is to build 4 patches and connect them with a corporate feed network. An example of corporate feed is this one. In my design the 4 patches are oriented in 4…
marcomanzoni
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Does GPS port of USRP B210 only used for GPSDO?

I try to use gnss-sdr these days with USRP B210. When I connect GPS antenna with RX port,gnss-sdr output well.But GPS antenna doesn't work when connect with GPS port. Does GPS port of USRP B210 only used for GPSDO?
kittygirl
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Is there a way to make `gnss-sdr` work with USRP B210 showing the PVT solution?

gnss-sdr seems to be working, but never show coordinates or synchronization with any satellite. I know that GPSDO included with my USRP only works with GPS ANT connection so, how can i specify to gnss-sdr to use GPS ANT connection? I'm using the…
Juan osorio
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