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Questions tagged [gps]

stands for Global Positioning System, a satellite based navigation system

-4
votes
1answer
71 views

Would it be energy efficient for phones to include actual GPS chip? [closed]

None of the smartphones today have dedicated GPS chips in them, they only have a GPS capability that stems from byproduct features of the modem chips. Because of that, the GPS capability is very ...
2
votes
2answers
234 views

Are Civilian GPS signals cryptographically signed?

As far as I understand, receiving enough GPS signals at the same time enables to deduce the position and the time. So I guess it is possible to use an offline receiver as a very precise clock? If so,...
14
votes
1answer
1k views

Official GPS protocol documentation?

Searching for "GPS protocol" reveals many sources for processed GPS data, e.g. NMEA or binary outputs of GPS units. Where is the official documentation for the GPS satellite - receiver protocol? Or ...
0
votes
0answers
31 views

Example GPS NAV Data

Where I can get example NAV data in bit stream sent by GPS satellites? I want develope embedded application using C program for PVT computation
1
vote
1answer
41 views

Electromagnetic wave equation for GPS waves

Recently, I came across a source which stated the model of a GPS L1 wave was: My question is, how was this equation derived?
0
votes
1answer
68 views

Which Board Should I Use For High Frequency GPS?

This is a very general question, hopefully with the amount of information I provide you will be able to steer me in the right direction. I am trying to build a very versatile GPS receiver, with ...
6
votes
1answer
58 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
47 views

Adafruit 3G Module sends data but don't accept it

I'm having trouble sending commands to the GSM/GPS/3G module from Adafruit. It gives me status data at bootup without any issues (takes a few seconds). The product in use is this: https://learn....
3
votes
2answers
63 views

Top Ground Copper pour in PCB having three RF Sections

I am designing my second RF board (First one had BLE). This board has LoRa Components (SX1257 and SX1301), GPS (MAX-6) and 4G LTE Module (SIM7600). All the components are on top layer (red layer). My ...
0
votes
0answers
36 views

Can a GPS Module and Bluetooth Module use the same RX/TX Ports Arduino

I'm wondering if I can use the same ports for the GPS module and Bluetooth module? I want to find my location and then Bluetooth it to my phone but both require RX/TX ports. Is this possible if I ...
2
votes
2answers
91 views

Why does Lidar have GPS, serial, and PPS input?

Many commercial Lidar systems have GPS, PPS, and serial interfaces. What's the application and how's it being used?
6
votes
3answers
812 views

gps performance for synchronization

I can't understand why GPS reciever clock is very good (stratum 0). I know it's very accurate and pure within itself; but when it passes through a long distance wireless channel, then it has low power ...
0
votes
1answer
67 views

Is a voltage level shifter necessary?

I am using an STM32F100xx MCU and I want to communicate via UART with a GPS module, specifically the A7 Thinker GPS GPS Module with A7 Thinker from Aliexpress This module, when a 9V battery is used, ...
0
votes
1answer
109 views

Selecting DC Blocking Capacitors for GPS, LoRa

I am designing a transmitter and receiver part of LoRa and GPS. It requires DC Blocking capacitors. I was looking for capacitor over digikey and I am amazed most of the manufacturer haven't specified <...
0
votes
1answer
30 views

GPS start mode query

I am using SIM808 GPS/GSM module. I came across Cold start,Warm start and Hot start in GPS Modules while developing code for a GPRS Tracker for car. I know the difference between them.My question is ...
1
vote
1answer
67 views

Why DC block is used for GPS receiver tested using a simulator via an active antenna?

Reading up GPS testing using a simulator and came across several articles which suggest requiring a DC block capacitor in the RF path between the GPS Simulator+Attenuators & Active Antenna. Some ...
1
vote
1answer
48 views

How are antenna arrays synchronized for direction finding/localisation?

How are antenna arrays synchronized for direction finding/localisation? For example, if the processing unit is located closer to one antenna then another, it will see the signal from the closer ...
0
votes
1answer
74 views

convert Ascii value to Binary or text

I have a GPS Tracker that connects and send data to a defined public server: port through GPRS connection. I am getting the result on the terminal. I have provided with a manual. I don't understand ...
0
votes
0answers
48 views

Adafruit Ultimate GPS sendCommand

EDIT: Solved, Problem was with not sending "\r\n" at the end of the sentence. I'm trying to control Adafruit Ultimate GPS through STM32F407, there is an official Arduino Library and this library has ...
1
vote
0answers
75 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
90 views

PCB layout for chip antenna

I recently made my first PCB. I ordered it from China and soldered it up on my homemade oven, and it's working awesome. I've already started a list for rev 2. There is one issue that I'm hoping I ...
0
votes
1answer
86 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 ...
0
votes
1answer
83 views

Blocking DC power to active GPS antenna

I would like to connect two GPS receivers to a single active antenna letting the DC voltage form only one receiver to reach the antenna. In this blog post the guy made his own RF part by putting a ...
0
votes
1answer
48 views

GPS and PIC16F876A

I am trying to configure a GPS receiver with PIC16F876A. In the code below i am receiving characters from UART, and checking whether received character is $. If ...
5
votes
4answers
99 views

Receive GPS Antenna and cable simple confirmation of operation

I am in need of testing a GPS antenna and cable assembly after installation at a reasonable cost. I have a GPS antenna installed on an airplane, then the coax cable from the antenna goes down to the ...
0
votes
2answers
75 views

GPS Antenna Testing

I want to test my GPS antenna. The problem is that my test setup is inside the room and not near to the window. It is not getting locked. Now as the setup has several connections, I can not take my ...
1
vote
2answers
185 views

Impedance matching: L-network or micro strips?

I'm trying to embed a u-blox neo6m gps module to an stm32 controlled board. I'm planning to connect the module to an SMA connector and use a 50ohm antenna. The datasheet of the neo6m states that the ...
0
votes
2answers
65 views

Optimal sensor for measuring object velocity in an open area?

I am trying to measure vertical and horizontal speed of an object attached to a parachute. It will be launched from a low altitude and in an open area, allowing satellite GPS lock. Data treatment ...
1
vote
1answer
133 views

What is the difference between GPS and GNSS? [closed]

I'm looking for a GPS module for my project but I've found some modules with GNSS what is the difference between GPS and GNSS? What module do you recommend I'm using BLE? Thanks
-3
votes
1answer
144 views

Trying to find documentation on UNV-SIM7100C-EVB MINI-V1.11

As the title states, I have the UNV-SIM7100C-EVB MINI-V1.11 connected to my Nucleo-F401re board and am trying to get GPS working. Can anyone help? EDIT: I'm looking for the one bought from here: ...
8
votes
5answers
1k views

GPS QA during manufacturing

Testing and integration engineers on electronics.stackexchange How do you quality check if a GPS module and its subsystems are up to the mark during manufacturing? ...
2
votes
1answer
165 views

GPS - Noise Figure Analysis

I am trying to analyze all components in one home-made GPS receiver and I am stuck with figuring out how to determine Noise Figure at the mixer output. See picture below: If we are going from the ...
0
votes
1answer
249 views

What is GNSS EPO orbit prediction in SIM868?

I'm little bit confused about the purpose of GNSS EPO orbit prediction functionality in SIM868 over a hot start,cold start or warm start. I'm working on a GPS tracker project and which among the ...
0
votes
2answers
149 views

Does GPS module need a wireless service? do I have to pay a service to get my gps module working?

Hi I'm new in the GPS world, I'm looking for a GPS module to track X amount of object the question is do I have to pay any service (cellular, data,etc) to get my gps working? I'm sorry for the dumby ...
0
votes
1answer
83 views

Converting 5v to 3.3V for GPS purpose while keeping noise at the lowest

I'm trying to create a very simple module that consist in powering a GPS ublox - NEO-M8U - with a micro USB & using an active antenna. Later on, I will add more features but I just want to make ...
2
votes
1answer
446 views

SIMCOM vs UBLOX [closed]

I would like to know what are your thoughts on the following below. I am designing a GSM tracking device with a SIMCOM808 module and I am speaking to an antenna supplier that advises me to rather go ...
0
votes
0answers
39 views

RF Explination for CC2500 transceiver to a GPS

In the photo is a design for the RF input for a CC2500 RF Transceiver and I am finding the documentation a bit fuzzy. I was just curious if it was possible to get a simplified definition for what is ...
0
votes
2answers
261 views

NMEA via RS232 and PPS (TTL) splitter

I have GNSS device that outputs NMEA messages via RS232 PPS signal via a digital out (TTL) I need to distribute both the RS232 and the PPS signal to more than 1 system (currently 3, but could be ...
0
votes
1answer
64 views

GPS antenna of a phone works even it is placed inside, but why its not working indoor

Sounds blunder, but trying to figure out how. I have heard its best to have line of sight to sky for GPS receivers to work. But in phones it could be on back side or in the PCB itself (I guess). So ...
1
vote
1answer
266 views

Why time period of GPS PPS signal is not accurately equal to 1 second. (7 to 10 mirco sec less)

I've multiple nxp K60 controller running at different ppm crystals. All have a GPS modules, i want to adjust their clocks using pps signal from gps. Whenever K60 controller will start it will adjust ...
0
votes
1answer
128 views

Is it posible to use AM/FM antenna as GPS antenna? [closed]

Having installed a tablet (Nexus 7) in the car dashboard, the GPS receiving signal seems to be too weak (specially in places with lots of buildings/trees around). So I thought about opening the tablet ...
2
votes
0answers
57 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 responsible to run my program beside it's internal firmware,does any one here with such experiences? SIMCOM has a document about ...
0
votes
2answers
103 views

Can a GPS receive its signal from within the engine compartment of a vehicle [closed]

I want to place the GPS and GPS antenna inside the engine compartment of a vehicle. Will the device acquire an accurate fix?
0
votes
3answers
64 views

Theory: Creating “LPS” transmitter for GPS receivers

As I understand it, GPS works by having transmitters with known locations send a timestamp, and calculating the time it took to receive it, so that you can triangulate your own position, (essentially ...
0
votes
2answers
142 views

Can someone check this so I don't fry someone's gps/transponder?

I am helping someone out over at aviation stack exchange -- they want a signal led for their gps receiver to do a preflight check to make sure it is working. They basically want to be able to press ...
79
votes
6answers
13k views

Why does smartphone GPS find its position much faster than a GPS module?

When I'm using the arduino GPS module it usually takes a couple of minutes for it to start sending data. And it seems that it's usually the case with all GPS modules since they need to "listen" to the ...
0
votes
2answers
101 views

Choosing hardware for an RF application [closed]

My goal is to build a battery powered RF transmitter that will reach its accompanied receiver through trees, tall grass, brush, and some outside terrain at a reasonable distance (up to a couple miles ...
1
vote
2answers
126 views

Inaccuracy in the GPS data

How can I get the inaccuracy associated with the GPS data. For example when I read lat, lon, speed, heading data from a GPS receiver, how can I get an approximation on the inaccuracy that is ...
1
vote
2answers
236 views

Disciplined oscillator using counter+micro

I am working on implementing a disciplined oscillator to increase the accuracy and long-term stability. The oscillator would be a VCTXO running at about 25 MHz. My thought is to have a 32-bit counter ...
3
votes
1answer
569 views

How to tune GPS Antenna with a PI circuit and spectrum analyzer?

I am designing a wearable product that uses GPS. In prototypes up to now we have used a patch antenna, and it worked great, however in this revision to cut down on size, we put in a chip antenna, ...