The Global Positioning System (GPS) is a space-based global navigation satellite system (GNSS) that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites. The GPS project was developed in 1973 to overcome the limitations of previous navigation systems, integrating ideas from several predecessors, including a number of classified engineering design studies from the 1960s.
A GPS receiver calculates its position by precisely timing the signals sent by GPS satellites high above the Earth. Each satellite continually transmits messages that include the time the message was transmitted
precise orbital information (the ephemeris) the general system health and rough orbits of all GPS satellites (the almanac).
Three satellites might seem enough to solve for position since space has three dimensions and a position near the Earth's surface can be assumed. However, even a very small clock error multiplied by the very large speed of light the speed at which satellite signals propagate results in a large positional error. Therefore receivers use four or more satellites to solve for the receiver's location and time.
The very accurately computed time is effectively hidden by most GPS applications, which use only the location. GPS has become a widely deployed and useful tool for commerce, scientific uses, tracking, and surveillance. GPS's accurate time facilitates everyday activities such as banking, mobile phone operations, and even the control of power grids by allowing well synchronized hand-off switching.
This GPS receiver is powered by 2 AA batteries. They are only strong enough for the GPS to stay on for about two hours, and this seems like quite a waste. I would like to be able to use a larger battery, and sometimes even an AC adapter...
Views: 2438 | Votes: 31 | Comments: 1 | Rating: 9 | Rank: 0 | Added: Mar 28, 2013 |
GPS Data Interconnect
For the Garmin 45, GPS II, and some other Garmin units, there is a set of power & data connector/harnesses available. (Ham Radio Outlet and West Marine sell one cable only for $40, or the cable & cradle for $65, approximately.) However, the leads are long. Rather than cutting them down for our use, we recommend preparing the end according to the specification shown below, and then coiling the excess cable...
Views: 2404 | Votes: 42 | Comments: 0 | Rating: 9 | Rank: 0 | Added: Mar 19, 2013 |
PC Based GPS
The advent of new high-speed technologies and the growing computer capacity provided realistic opportunity for new cost effective technologies and realization of new methods of innovations. This technical improvement together with the need for high performance techniques created faster, more accurate and more intelligent products using new drives and advanced control algorithms...
Views: 1524 | Votes: 90 | Comments: 0 | Rating: 6 | Rank: 0 | Added: Mar 16, 2013 |
My GPS LCD Display Project
This is a project that I started back late 2003 when I just starting to learn PIC programming. I wanted to building something that actually did somthing useful. This project is based on a PIC16F84. I actually came up with this idea and then after doing some searching I found that a few people had the same idea. But, I wanted to build my own that I could call mine, developed by me...
Views: 1077 | Votes: 77 | Comments: 0 | Rating: 6 | Rank: 0 | Added: Mar 10, 2013 |
1.575 GHz GPS WITH µPC8211TK, µPC8215TU, & µPC8226TK
The µPC8211TK, µPC8215TU, and µPC8226TK are silicon germanium (SiGe) microwave monolithic integrated circuits (MMIC) designed as low noise, high-gain amplifiers for GPS and mobile communications. These ICs are manufactured using our 50 GHz fmax UHS2 (Ultra High Speed Process) SiGe bipolar process. The use of these three devices in evaluation boards implementing LNAs (Low Noise Amplifiers) at 1.575 GHz GPS is described in this document...
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Diagram description GPS support kit
The GPS interface can be fed in 2 ways: with a stabilized 5V supply or with a 10 to 25V unregulated DC supply. In both cases the power is fed into the RJ45 connector on point 8. Pin 7 is DC ground. The power supply current is first secured with a slow 315mA fuse (in socket). Then there is a Transzorb device to ground. This device is a short-circuit for reverse polarity voltages and for voltages above 27V. It causes the fuse to blow and in doing so, protecting the.....
Views: 3679 | Votes: 39 | Comments: 0 | Rating: 1 | Rank: 0 | Added: Jan 20, 2013 |
1.57-GHz Front-End for GPS Receiver
The GPS is based on 24 satellites located in six orbital planes at a height of 20 200 km and circle the Earth every 12 h. Each plane is inclined at 55 to the Earth’s equator and contains four satellites. The GPS positioning is based on oneway time-of-arrival ranging. Each satellite sends the universial time (UTC) and navigation data using a spread spectrum code division multiple access (CDMA) technique. A receiver can calculate its own position and speed by correlating.....
Views: 2489 | Votes: 34 | Comments: 0 | Rating: 2 | Rank: 0 | Added: Dec 18, 2012 |
external antenna for the GPS
Antenna #2 is used as a
*transmitting* antenna, and is connected to antenna #1 via coax cable.
The transmitting antenna is then placed close to the GPS receiver`s own
internal antenna, and the GPS signal is coupled into the GPS receiver`s
antenna through the air...
Views: 3355 | Votes: 10 | Comments: 0 | Rating: 8 | Rank: 0 | Added: Dec 8, 2012 |
A GPS-Based Frequency Standard
Frequency accuracy has been a topic of special interest to many amateurs and experimenters since the early days of radio. Until recently, the best frequency standard available to most hams was a crystal oscillator carefully adjusted to zero-beat with a station of known frequency, such as WWV...
Views: 2157 | Votes: 53 | Comments: 0 | Rating: 9 | Rank: 0 | Added: Nov 29, 2012 |
Inertial-navigation system uses silicon sensors
A strap-down inertial-navigation system uses silicon sensors to measure displacement without entailing the bulk and expense of moving parts or GPS receivers. For example, a three-axis accelerometer and three angular-rate sensors can determine the position and velocity of a vehicle such as a robot or radio-controlled aircraft...
Views: 2145 | Votes: 43 | Comments: 0 | Rating: 6 | Rank: 0 | Added: Nov 8, 2012 |
Variable GPS Jammer
A low cost device to temporarily disable the reception of the civilian coarse acquisition (C/A) code used for the standard positioning service (SPS) on the Global Positioning System (GPS/NAVSTAR) L1 frequency of 1575.42 MHz. This is accomplished by transmitting a narrowband Gaussian noise signal, with a deviation of +/- 1.023 MHz, on the L1 GPS frequency itself. This technique is a little more complicated than a simple continuous wave (CW) jammer, but tends to be more.....
Views: 1557 | Votes: 51 | Comments: 0 | Rating: 8 | Rank: 0 | Added: Sep 28, 2012 |
Low-Power IC Packs GPS Receivers
This highly integrated GPS receiver IC improves upon earlier-generation devices by including more components in a smaller package with a reduction in power consumption...
Views: 4980 | Votes: 99 | Comments: 0 | Rating: 0 | Rank: 0 | Added: Aug 29, 2012 |
Tracking System using GPS and GSM modem
In this project AT89S52 microcontroller is used for interfacing to various hardware peripherals. The current design is an embedded application, which will continuously monitor a moving Vehicle and report the status of the Vehicle on demand. For doing so an AT89S52 microcontroller is interfaced serially to a GSM Modem and GPS Receiver. A GSM modem is used to send the position (Latitude and Longitude) of the vehicle from a remote place. The GPS modem will continuously give.....
Views: 2380 | Votes: 95 | Comments: 0 | Rating: 9 | Rank: 0 | Added: Aug 23, 2012 |
GPS LCD Display Project
This is a project that I started back late 2003 when I just starting to learn PIC programming. I wanted to building something that actually did somthing useful. This project is based on a PIC16F84. I actually came up with this idea and then after doing some searching I found that a few people had the same idea. But, I wanted to build my own that I could call mine, developed by me. The whole idea is, I have several GPS units with no display and I wanted an easy way to see.....
Views: 1091 | Votes: 57 | Comments: 0 | Rating: 7 | Rank: 0 | Added: Jul 13, 2012 |
How to Construct a Cable for Garmin GPS receivers
Some Garmin GPS receivers are capable of running off external power ranging up to +32VDC or more, whereas others can only accept a maximum of +8VDC...
Views: 3784 | Votes: 76 | Comments: 0 | Rating: 0 | Rank: 0 | Added: Jun 14, 2012 |
GPS LCD Display Project
The circuit it`self is pretty simple, take in the data on one pin, parse it, format it and then display it to a 4x20 LCD module (Hitachi Chipset). That is the basic idea, but I might add in somthing like a mechanical encoder that would allow for changing options or changing settings in the display unit. This might be as simple as a SPDT (Singe Pole Double Throw) switch if the options are as simple as two settings...
Views: 3619 | Votes: 73 | Comments: 0 | Rating: 2 | Rank: 0 | Added: Jun 12, 2012 |
Do law enforcement agents need to obtain a warrant based on probable cause to track a vehicle's movements?... - Criminal Law.
The US Circuit Court of Appeals ruled that Americans have no reasonable expectation of privacy when carrying cell phones, allowing police to track GPS signals without a warrant or probable cause.
The 1st U.S. Circuit Court of Appeals, in United States v. Sparks, et al., contemplated the recent SCOTUS ruling in US v. Jones before ruling that evidence obtained as a result of a warrantless pla...
Both the district court and Tenth Circuit assumed, without deciding, that GPS pinging constitutes a search. They also agreed that though there were no explicit requests for GPS, other information a...
The Tenth Circuit published its opinion in United States v. Barajas on Monday, March 4, 2013. Defendant-Appellant Samuel Barajas was convicted of drug charges and using a communication facility, a ...
Autobahn Country Club, North Circuit. Posted by admin on January 2, 2013 in Tracks | 0 comments. Registration Instructions for Autobahn Country Club, Saturday, April 6, 2013. 1) Please review the c...