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QST_GPS
http://www.rt66.com/~shera/QST_GPS.pdf As shown in the block diagram of Figure 1, the device consists of five sections: a commercial GPS receiver, a voltage-con-trolled crystal oscillator (VCXO), a phasemeasuring circuit, a microprocessor (CPU) with a few interface chips, and a digital-to-analog converter (DAC) to control the VCXO. Figure 2 shows the controller board, which includes almost everything except the GPS receiver and the VCXO. First, set S4 (U11, pin 4) to correspond to the polarity of the VCXO control voltage. If you change the value of these resistors, keep in mind that the peak-to-peak voltage at U1 pin 14 Figure 3--- Schematic of the controller. GPSV6insertE http://www.cambridge-aero.com/manuals/GPSV6insertE.pdf D. Ellis March, 2000 This ROM Version upgrades the GPS-NAV with the following features and bug fixes: Items 1-4 were first introduced in GPS-NAV Version 5.4 1. The GPS-NAV does this in the following way: A PEV is entered in the flight log when the GPS-NAV "ON" key is pressed or when a TASK is started. A pushbutton switch attached to a six conductor cable is plugged into the GPS-NAV "Display" port. 2. Password activation of advanced Cambridge Palm-NAV software features Palm-NAV software is the intellectual property of Cambridge Aero Instruments. Previous versions occasionally stopped sending messages between the GPS-NAV flight recorder, the GPS-NAV LCD screen, and the Palm-NAV. SyntraqDataSheet The Syntraq(TM)/I integrates the Motor o l a ® C re a t a L i n k ® 2XT Tw o - Way Transceiver and the M o t o ro l a ® M12 Oncore ® GPS Receiver in a single, custom package. This b o a rd provides power re g u l a t i o n and a communication link between the C re a t a L i n k ® and the M12. Four LEDs on one end-plate indicate unit power up, XT receiver status, GPS data transfer, and data transmission. The p o w e r, GPS antenna, and pager antenna connectors a re provided on the rear end plate. Syntraq(TM)/I-Sub is a OEM subassembly option available for customer integration. gpsinfo http://www.syz.com/gps/gpsinfo.pdf This document will provide you with the information you need to construct virtually any type of cable you may require, whether you want to connect your GPS to a computer, two GPS units to each other, or to provide power to your GPS. Garmin provides a centre plastic pin on the connector of their GPSes which are limited to low input voltages. If you're building a regulated circuit for a low voltage receiver that has a centre plastic pin, this plug must be left out. For specific details on how to construct a cable, please refer to the "Connector Pinouts and Signals" diagrams to the right, as well as the information on the following page. 0210036 http://www.arrl.org/tis/info/pdf/0210036.pdf If you operate APRS or just need an external antenna for your GPS receiver, here's one that is easy to build yet offers surprisingly good performance in a compact size. A ¼ wavelength "parallelplate" transmission line (printed circuitboard material) serves as the connection method and mounting post for the dipoles. If your GPS unit has a BNC antenna connection, you can use an Ethernet coax cable found at most computer stores. To make the parallel-plate transmission line, cut two 2-inch lengths of single-sided printed circuit board material that are 0.250-inch wide. Additionally, the second dipole is fed 90° out of phase with anFigure 4---Side (A) and front (B) views of the parallel-plate transmission line and radiating elements. MR614.appb http://www.rand.org/publications/MR/MR614/MR614.appb.pdf The 1920s witnessed the introduction of a more advanced technique---radionavigation---based at first on radios that allowed navigators to locate the direction of shore-based transmitters when in range.1 Later, the development of artificial satellites made possible the transmission of more-pre-cise, line-of-sight radionavigation signals and sparked a new era in navigation technology. Satellites were first used in position-finding in a simple but reliable two-dimensional Navy system called Transit. Detection System (IONDS); later GPS satellites were fitted with a new sensor known as Nuclear Detonation Detection System (NDS). The Air Force provides the "platform"---the GPS satellites---and operates the system; DoE provides the sensors through its national laboratories, Sandia and Los Alamos. gps A lmost everyone has heard of the Global Positioning System by now, and many radio hobbyists own a handheld GPS receiver. For the uninitiated, the GPS system works with a network of 24 satellites orbiting some 12,500 miles up in the sky. Each one has an atomic clock to set the precise timing that is part of the math used by a land-based a GPS receiver to triangulate its location on the face of the earth. When people want to know how much to spend on a GPS receiver, we ask if they want to see a map in their hand. GPS Basics GPS can be used to achieve all of these accuracies in all of these applications, the difference being the type of GPS receiver used and the technique employed. GPS was originally designed for military use at any time anywhere on the surface of the earth. Even though the clocks in the satellite are very accurate (to about 3 nanoseconds), they do sometimes drift slightly and cause small errors, affecting the accuracy of the position. Multipath occurs when the receiver antenna is positioned close to a large reflecting surface such as a lake or building. For the position transformation, the WGS84 coordinates are projected onto a temporary Transverse Mercator projection and then the shifts, rotation and scale from the temporary projection to the "real" projection are calculated. GPS-Primer http://www.aero.org/publications/GPSPRIMER/GPS-Primer.pdf The men and women who created the Global Positioning System (GPS) were once young people like yourself. Using a GPS receiver, you are able to help ships avoid disaster by zeroing in on the position of the icebergs and notifying ship captains of their locations, perhaps averting disaster. The satellites transmit signals that can be detected by anyone with a GPS receiver. They relied on GPS receivers outside the tunnel to check their positions along the way and to make sure they met exactly in the middle. Many police, fire, and emergency medical service units are using GPS receivers to determine the police car, fire truck, or ambulance nearest to an emergency, enabling the quickest possible response in life-or-death situations. sa01 http://www.aopa.org/asf/publications/sa01.pdf The promise of access to every airport in the land in almost any weather was once a distant dream. But thanks to Global Positioning System (GPS) technology, the dream has become reality. Ground sites monitor GPS satellites then transmit correction to WAAS satellite through a processing station. IFR-approved panel-mount receivers should be available sometime in 2003, when the FAA says WAAS initial operational capability will be announced. One of the more confusing aspects of GPS operation is the hold function. The hold function tells the receiver, "wait a minute, don't start sequencing yet. In recent years, databases include localizer antennas as named waypoints; thus on an ILS-DME, the GPS should exactly match the DME distance. p-a10_ledvina One receiver, originally designed to run in DOS, will be the focus of a code migration to RTLinux. To provide insight into code migration from DOS to RTLinux, we will focus on the specific difficulties, discoveries, and enlightenments encountered. On the other hand, Linux, when modified to perform realtime computing, is an ideal candidtate for inexpensive realtime applications [3]. The DOS version of the code has several drawbacks; the first one is that the application code and the user interface are together in the same piece of code, and adding a new service would imply changing all of the receiver code. CFGPS http://www.cadmusmicro.com/PDF/CFGPS.pdf Billionton has developed the smallest GPS Navigation CF Adapter for your Pocket PC. With optional software you get features like dynamic voice navigation, off-route warning and detailed street maps. Now yor can turn your Pocket PC into a true GPS Navigation system. CADMUS MICRO, INC. 1840 Carlos Avenue Ontario, CA 91761 U.S.A. | |
