stands for Global Positioning System, a satellite based navigation system

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1answer
81 views

Determining the Longitudes and Latitudes from raw NMEA of unknown format [on hold]

I am given a data set that has location data of an animal. The data set has very large number of records. The task is to simulate the motion of this group of animals in Matlab or in any other suitable ...
-1
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0answers
31 views

NEO 6M GPS Module: Resistance between pin 23 and 24

I bought a NEO 6m GPS module from China. It is not working properly so I visually checked it. It looks like pin 23 (VCC) and 24 (GND) of the NEO-6M chip are bridged, and I measure 0 Ohm between them. ...
0
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1answer
65 views

GPS Accuracy - is it relative or absolute?

If a GPS unit reports accuracy to 1 meter, does that mean that the receiver's absolute location at any time could be up to 1 meter incorrect in any direction, -or- does it mean that the initial ...
0
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33 views

help needed for ublox pcb

I am back to the basic and I want to get I right this time, I am asking to check my prototype of just GPS + patch antenna, I have made a trace of 1 mm width, as I read online about 1.6 mm thickness, ...
1
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2answers
92 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 ...
0
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1answer
48 views

Measuring vehicle's forward and lateral acceleration using a smartphone

I want to measure the acceleration (forward and lateral separately) using an android smartphone device in order to be able to analyse the driving behavior. My approach would be as follows: 1. ...
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votes
2answers
55 views

Transmit location data globally [closed]

While looking at products like: https://www.victorinox.com/global/en/Products/Travel-Gear/Accessories/CheckSmart-Luggage-Tracker/p/601169 This product is able to send some data about the ...
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1answer
31 views

Gps l2 frequency Usage

Hı, Does gps l2 frequency signal, carrying p code, can be used without permission of US. If not how dual frequency gps receiver decrypt p code. I mean what is authorization process software or ...
3
votes
0answers
132 views

Cannot get data to rx register of msp430fr5739

I am working on a gps project with msp430fr5739. I have done some code for gps. the nmea string handling is workings fine in my code when manually entered a few nmea sentences, but I am stuck with ...
1
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0answers
34 views

how to sample and modulate a gps gold code

I am trying to simulate the data transmission of a GPS satellite. Telecommunications is not my field so I am struggling a bit with some concepts. I managed to generate the Gold code of the GPS ...
1
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1answer
87 views

How to get sub-meter or centimeter GPS accuracy?

I'm thinking about building a gps system for a tractor. The gps receiver can be placed on the roof of the tractor to minimize interference. Regular GPS receivers are accurate upto "a few meters". ...
0
votes
1answer
22 views

Add ufl connector to internal patch antenna

Hey i am using Ublox neo 6m gps for some project and it has a U.fl connector and i dont have an antenna for it.I went to buy it and shopkeeper game me an ceramic internal antenna with a pin at its ...
1
vote
1answer
48 views

Why is GPS module acting strange?

I am working on a Arduino based quadcopter. The Arduino being used is a Blend Micro. Not shown in the following diagram are 4 infrared sensors, 1 ultrasonic sensor and a 9 axis accelerometer. The ...
4
votes
1answer
68 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 ...
0
votes
2answers
88 views

MEMS: why INS + GPS? [closed]

I have read in the Internet that in the most cases people prefer using INS (accelerometer + gyroscope) + GPS sensors. I have read they can compensate each other errors, but is it possible to obtain ...
1
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2answers
253 views

Any idea on what this component is?

It's an 0402 sized component. Measures about 50 milliohms out of circuit. I also measured it with a cheap LCR meter and it shows -47nH. Capacitance measures 350mF. So I'm pretty sure it's a jumper. ...
4
votes
1answer
33 views

Return current on Adafruit GPS

This might have a dumb answer, but here goes... This is a picture of the u.fl connector on the Adafruit ultimate GPS. With RF lines, I know you want the shortest return path. So why did they put ...
0
votes
3answers
100 views

Does powering a module with 5v instead of 3.3v affect it's logic level? [closed]

I bought a NEO-6 u-blox 6 GPS Module (datasheet, pages 9 and 14), which has a standard serial connection. I have a USB to serial converter, which is 5v logic. This board says it can be supplied 3v-5v, ...
0
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0answers
33 views

IEEE codes for GPS environmental constraints

the documentation format required as part of my design subject needs a constraint format that i cant find I'm looking for IEEE standard constraint number/codes/std for GPS environmental/landscape ...
0
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1answer
67 views

How to make SirfStar IV chip operate as I2C slave only?

I bought a GPS that has SirfStar GSD4e chipset inside. I see with the logic analyser that when in I2C mode it is writing to the bus. I understand by that that it is in master mode. How can I make it ...
0
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1answer
71 views

Generating Hexadecimal checksum for a NMEA (PMTK) message

I am trying to use quectel L80 GPS receiver for my project. I am trying to configure the L80 using the PMTK strings. But the problem is the string should also contain a hexadecimal check sum. eg. ...
7
votes
1answer
199 views

how is the 1PPS signal generated in GPS receivers?

The question might seem stupid, but the time of flight from the satellite is unknown and moving, the doppler effect is skewing the frequency (and is not constant due to the relative trajectory) and ...
0
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2answers
131 views

GPS 1 PPS Aligment Clock Signal Generator

i want to do GPS 1 pps aligment clock signal generator. Clock signal should be at 24.576 Mhz and voltage level Vmax= 3.3 V and Vmin=0 V DC. How can i do that? It is very important to align between GPS ...
0
votes
1answer
80 views

GPS Almanac versus Sky Search

The total almanac data is transmitted in 25 navigation messages. Each navigation message takes at least 30 seconds to transmit. So, receiving the almanac data from the satellites takes at least 12.5 ...
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1answer
62 views

GPS antenna type

i want to interface a gps module and an antenna. I found this kind of antenna (example) It does not mention its type. Is this an active or a passive antenna? How to be able to know by myself without ...
0
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1answer
203 views

Problem communicating between SIM908 and Arduino UNO

I'm trying to make my Arduino UNO work with the SIM908 GPS/GSM shield with this simple code just to make sure that it works first: ...
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0answers
96 views

GPS Active Antenna Circuit

I'm adding an active antenna to a design and had a few questions. Based on multiple data sheets for similar products, everyone uses the same simple DC supply with a RF blocking inductor and DC ...
2
votes
1answer
75 views

Is the Garmin GPS 12 on board 16.368 MHz oscillator GPS controlled?

My plan is to use my old Garmin GPS 12 as a frequency standard. As it has no pps (pulse per second) output I am thinking about using the on board oscillator as the clock source. So my question: Is the ...
1
vote
2answers
144 views

SAW and GPS Antenna

I'm designing a system with a GSM modem and GPS receiver. In order to achieve out of band rejection I'm planning on putting a SAW filter right after the antenna. Often on the internet I see a few ...
2
votes
1answer
67 views

GPS RX module Implementation

I have been tasked with designing a low power sensor system and the customer has decided location would be a great option. I have done GPS before but only with complete modules (Ant. + IC). To keep ...
0
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1answer
97 views

What type of connector is this Velodyne interface box GPS connector?

Velodyne VLP-16 lidar's interface box has this connector. What type is it? Could not find this from the manual.
0
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2answers
330 views

Calculate distance travelled by vehicle using “knots” of NMEA data

I'm using L80 quectel GPS module. Which sends the NMEA protocol data string which has latitude, longitude, UTC time, knots, etc. We are going to use this GPS module in a vehicle. We have to calculate ...
0
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1answer
137 views

Antenna gps neo 6m

I am designing a pcb which has the module ublox neo 6m, instead of using the normal antenna I was looking to use a ceramic which should work with ublox. I have got this: ...
0
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2answers
38 views

Ways to communicate GPS coordinates to a central server wirelessly from a wearable device

I am currently looking at designing a wearable device for a client, which can communicate GPS coordinates back to some sort of central server (to then be sent out to other communicating devices such ...
3
votes
2answers
185 views

GPS positioning faster than 1Hz

I am a systems engineer working with various instrumentation devices for ground platforms. These platforms can vary in speed from 0-60+mph. Current instrumentation provides TSPI at 1Hz and is based on ...
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votes
1answer
89 views

External GPS antenna for smart phones [closed]

Is there a smartphone GPS boost or external GPS antenna commercially available for smartphones. To hook up to smartphones via audio input for example?
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1answer
201 views

GPS antenna ground plane design considerations and limitations

I have a PCB design which incorporates a GPS unit. I'm looking at refining the PCB, and I'm looking to do away with the long cable length, occupation of space within my enclosure, current ...
2
votes
1answer
226 views

PIC24FJ128GA202 UART2 and UART3 not working?

I am working in pic24fj128ga202 microcontroller with L80 and M95 module. here L80 module connected with uart2 and M95 module connected with uart3. now uart1 working normally but uart2 and uart3 not ...
5
votes
1answer
291 views

GPS consideration for PCB with GSM (interference, setup etc)

I am working on a project which has a GSM and GPS on the same PCB (fairly near each other in an enclosure). Since I am not familiar with GPS I was wondering if any of you could give me some tips on ...
3
votes
1answer
128 views

How is impedance matching for chip antennas practically done?

I designed a PCB for a GPS tracking device and i want to further develop it to have a smd gps antenna mounted on the board. I know that for optimal signal transfer i need to design a matching circuit, ...
0
votes
1answer
151 views

Is anything wrong with my PCB?

I am designing a PCB and I just want to make sure nothing is wrong before I send it off to the fab house. If one of you knowledgeable stack exchangers could give me some feedback, I would really ...
4
votes
1answer
149 views

GPS Power consumption MTK3339 vs SirfIII for periodic logging application

I am currently working on redesigning a SirfIII based battery operated GPS logger. A MTK3339 based GPS module has been selected due to overall (advertised) performance. The GPS logger uses a ...
1
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1answer
119 views

Turning a frequency locked loop into a phase locked loop

I want to use a GPS module (with a PPS output) to ultimately generate a 5kHz timing signal that is phase-aligned with the PPS positive edge. ...
2
votes
1answer
332 views

Unable to receive GPS data from Quectel L80 GPS module

I have a Quectel L80 GPS module with PIC24fj128ga202. I am using UART2 to get GPS data from the module and I transfer the received data to hyperterminal, using UART1. Between PIC and PC I there is an ...
4
votes
2answers
83 views

Is GNSS S/N equivalent to C/N?

I work in developing software that integrates with GPS and Galileo receivers. I've struggled for years with inconsistencies in documentation for the NMEA emitted by such receivers, and I've decided to ...
1
vote
1answer
97 views

How would you jerry-rig an android phone for continuous autonomous operation?

I want to use an android phone as dash-cam with GPS tracking capabilities. It is supposed to run 24 hours a day, 365 days a year. If the phone / app hangs, the user cannot be expected to ...
23
votes
4answers
3k views

True GPS Location - At the Antenna or Receiver Chip?

Suppose I have a GPS unit attached to an antenna through a 50 meter coax cable. How would the location as calculated by the GPS unit be affected by the cable length? As a bonus question, how would ...
0
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1answer
52 views

Reducing GPS coldstart if we know where the user is

I'm working on a project with GPS and I was wondering if it would be possible to reduce the cold start time by passing in some data. Let's say I already had a fairly good idea of where the user was ...
1
vote
1answer
119 views

Can I create paths to two external GPS antennae but use only one

I am making a PCB for a SIM968 GSM/GPS device. Printing PCBs in my country is expensive. I am making this PCB for two different purposes. One is to work in an open environment where there is enough ...
0
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3answers
813 views

SIM908 GPS STATUS “Location Unknown” Error

I'm using a SIM908 module on a custom board and am having trouble getting the GPS location from it. Everything else works on the module. I can send SMS, make calls and send and receive data from a ...