Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [gnss]

51 questions
15
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How do receivers decode multiple GPS signals on the same carrier frequency?

I'm currently researching GPS signals and am trying to fully understand the path of a signal from satellite to receiver. I understand that mixed into the GPS signal is a C/A code as well as a PRN which aids in the process of CDMA that the receiver…
Justanothermatt
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14
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2 answers

What is the highest achievable update rate for a civilian GPS receiver?

I'm interested in knowing the maximum achievable update rate for a civilian GPS receiver. Specifically Receivers that depend exclusively on GPS satellites (e.g. not including IMU-based movement estimation to interpolate) The hypothetical limit (i.e…
user139772
12
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2 answers

GPS taking long time to fix out in the open

I am trying to use a ORG-1411 GPS (https://origingps.com/products/hornet-org1411/) to get location and UTC fix, using the breakout from Mikroe (https://www.mikroe.com/nano-gps-click). To parse the readings I am using ublox ucenter…
Swapnil Saha
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6
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1 answer

GPS L5C Differential? Max Update Rate(bits/s|Hz)?

The differential GPS chips use L1 and L2C to calculate the ionospheric interference. With the new GPS satellites, the new band L5C is being deployed, and I am wondering about the following things: Will L1 and L5C be used as new type of…
Jack Shephard
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1 answer

Why is it that the bandwidth of a patch antenna decreases with it's size?

I typically use a larger (25 mm) patch antenna in GPS/GLONASS receiver circuits. As you probably know, L1 bands for GPS and GLONASS are separated by roughly 25 MHz. For applications where I want to be able to view both satellite systems, I'll…
Samee87
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3
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Running Application on SIM808 GNSS module beside it's internal firmware

I'm trying to load my written program to SIM808 and the module will be responsible for running my program and also its internal firmware. SIMCOM has a document about doing this in SIM800 module but there are not any equivalent for SIM808. Does…
Mahmoud Hosseinipour
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2
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Why are there LC filters on the UART line to the M20050-1 GPS module?

I am designing an IoT device. In first version, I forgot to put the LC filters as in the datasheet. I found it after I get the prototyping board on my hands, but I thought it would be fine without these filters as I'd never seen such filters in the…
PCBCrew Engineer
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Proper PCB layout for GNSS ceramic patch antenna

I am designing a PCB that will require a GNSS antenna. The antenna will feed directly into a GNSS module located on the same board. It seems a popular antenna choice for this is a ceramic patch antenna. For example, this Abracon antenna seems like…
Nick
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Microcontroller GNSS time synchronization

I'm interested in having a Microcontroller trigger a device within a 1ms time of GNSS time every 100ms GNNS time. What is the best approach to this problem? Edit: I understand that GNSS may update at a one second rate or every 100 mS depending on…
FourierFlux
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High precision distance between two GPS devices (may be GNSS-SDR)

I wish to get to high precision distance between 2 not moving points. e.g. 1 cm accuracy for distance 1 km I think if I will catch same GPS signal in two points then distance between resulting coordinates would be highly precise even if…
Artem
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How does RF Coax cable impedance + Microstrip impedance mismatch affect power transfer

I have a passive GNSS antenna with a 6" 1.13mm shielded coaxial cable that connects to a u.FL connector. From the u.FL connector I have a 2" microstrip transmission line to the RF input of my GPS receiver. Altium's built in impedance calculator…
Samee87
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Does A-GPS require a GPS antenna?

I have a good understanding A-GPS functionality. I understand that assisted GPS is used to improve TTFF, works better indoors but costs more as you are using the mobile networks to determine the position. Let's say you have a simple PCB with a GSM…
jskidd3
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Why isn't my Teseo-LIV3FL's CEP value within the datasheet specifications?

Context: CEP is defined as the radius of a circle, centered on the mean, whose perimeter is expected to include the landing points of 50% of the rounds (Wikipedia.) According to the Teseo's datasheet, this module could reach 1.5m CEP with a roof…
Why Would You
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GNSS module Allystar TAU1302 has fix but does not output PPS

I have a microcontroller board Datagnss Tiny EVK with an integrated chip TAU1302 (Allystar). I can get a fix with expensive Tallysman antennas in a rural area, with over 30 satellites and SNRs exceeding 40. I can see L1 , L2C, and L5 bands , at…
Ksenia Semenova
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Noise factor in homemade software-defined GPS receiver

I'm building a homemade software-defined GPS receiver. I'm currently at a point where I can acquire and track strong signals but struggle to even detect weak signals. I've ruled out problems with my software -- I can easily detect all satellites…
Manuel Menzella
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