Questions tagged [gnss]

The tag has no usage guidance.

0
votes
0answers
23 views

GPS Fix but Pulse-per-Second Inop? [closed]

I'm using a UBlox MAX-M8Q interfacing with an XSens MTi-7 Inertial Measurement Unit. Antenna is a Tallysman 33-2920, which I believe has a slightly higher noise figure than is spec for the MAX-M8Q. ...
0
votes
2answers
46 views

coplanar waveguide vs microstrip for gnss and cellular?

coplanar waveguide vs microstrip for gnss and cellular? I read on internet microstrip is better for signals <30Ghz but some gps manufacturer (Delorme) said that coplanar is most efficient so it's ...
1
vote
0answers
50 views

Elevation accuracy of dual band RTK GNSS module? (ZED-F9P)

Does anyone know the accuracy of height given from the ublox F9P dual band GNSS module in RTK mode? Or any dual band RTK GNSS module in general? The website says up to 1 cm accuracy but I don't know ...
0
votes
0answers
43 views

GPS and Galileo signal reception with a broadband antenna

I have a passive antenna that covers a wide bandwidth (1.25 - 2.45GHz, RHCP, omnidirectional) which I'd like to re-purpose for Galileo signal detection. I don't have an option to get an application ...
1
vote
2answers
40 views

assited gps vs differential gnss [closed]

i am writing as essay evaulating accuracy of smart phone gnsss for GIS data collection for part of the essay i thougt it appropriate to mention DGNSS and Assisted GNSS. So far i understand Assited ...
0
votes
0answers
11 views

What is a difference between peak gain & avarage gain of an Antenna? How avarage gain is measured?

What is a difference between peak gain & avarage gain of an Antenna? How avarage gain is measured? For an antenna (e.g. GPS chip antenna) if avarage gain & peak gain given, which value should ...
0
votes
1answer
160 views

Through Hole (Vertically Mounted) SMA Connector on PCB - Feasible for GNSS Application?

Due to space constraints on a board I am designing, it is ideal to have the GNSS cable connecting vertically onto the top of the board. I haven't been able to find any edge-mounted connectors that go ...
6
votes
1answer
98 views

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: ...
0
votes
1answer
61 views

Board requirements for a chip PCB antenna?

TL;DR: What are the requirements of chip antennas like this one (without LNA) or this one (with LNA)? I see PCB size specs in the PDF, but I am not sure I understand how the rest has to look.Does this ...
1
vote
0answers
356 views

What kind of GNSS antenna is this?

I would like to know what types of GNSS antennas are on the images below (patch etc.) and also which one is better from the two (if any). They are being sold as "high precision" survey grade antennas. ...
0
votes
1answer
199 views

Can every L1 GPS/GLONASS/BeiDou GNSS antenna receive E1 Galileo too?

I want to buy a survey grade single frequency L1 GPS/GLONASS/BeiDou/Galileo GNSS antenna (survey antennas have a ground plane built in). I found a product that specifies it is a GPS/GLONASS/BeiDou ...
1
vote
1answer
62 views

FPGA Frequency Domain Based Beidou-3 B2a Coarse Acquisition Processor Using FFT

I'm using an ARM+FPGA platform to capture B2a (BeiDou or COMPASS) signals and determine the user position, velocity and precise time (PVT). The C/A frequency of B2a is 10.23MHz. If my sample rate is ...
3
votes
0answers
96 views

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 ...
2
votes
1answer
345 views

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 ...
1
vote
1answer
60 views

I'm comparing a couple of GNSS front-end modules. Is a lower In-band IIP3 point better or worse than a higher one?

I would typically compare the small signal gain and noise figure first. One of the FEMs requires an external matching component but other that they are very similar in terms of cost and foot-print ...
0
votes
1answer
270 views

sim808 GNSS location update

I'm working on a project in which I have to get current location at every 10 sec interval. I've used sim808 (GSM/GPRS & GNSS) using which I execute AT+CGNSINF command to get the location. I get ...
10
votes
2answers
6k views

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 ...
0
votes
1answer
102 views

Do I need a dummy load for a GPS satellite signal generator?

I'm in the process of applying for an FCC experimental certificate so I can be legal when I purchase a satellite generator. I found a used (calibrated) generator on eBay and want to know if I need a ...
1
vote
0answers
180 views

Obtaining GPS Pseudoranges from Code Phase

After the tracking process in a Software GPS receiver, I need to compute the pseudoranges between the receiver and the satellite (without having in mind the clock corrections). In the tracking process ...
2
votes
2answers
215 views

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 ...
2
votes
2answers
642 views

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 ...
5
votes
1answer
407 views

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 ...
1
vote
1answer
161 views

What's the purpose of this capacitor?

What's the purpose of this capacitor here? I certainly don't think it's for decoupling but maybe bypassing? I presume we don't want any of the amplified RF which might have sneaked by the inductor ...