VISPA A Mobile Digital TourGuide for Mountaineers
Erwin Lhnert1, Elmar Wittmann1, Juergen Pielmeier1, Florian SaydaIfEN Gesellschaft fr Satellitennavigation mbH 2 AGIS (Arbeitsgemeinschaft GIS), University FAF Munich

INTRODUCTION

Mountain walking/climbing as one of the major sporting categories today puts high requirements on maps, positioning and guidance combined with many safety-of-life issues (weather, accidents etc.). An intelligent sports assistant can be the key point to enhance the personal sporting confidence and safety of the professional and especially non-professional mountaineers. The Virtual Sports Assistant (VISPA) presented in this paper is a mobile digital TourGuide for mountaineers with main emphasis on information, guidance and orientation function. It consists of a service provider component and a mobile user component on Pocket PC basis, connected with a GPRS cellular phone, GPS receiver and digital compass. The core services offered to the user include navigation- and general information functionality. The data communication between server and client will be provided via the Internet using GPRS. In the following a system overview on VISPA will be given.

PROJECT OVERVIEW

The VISPA project is carried out in the frame of the ASTRON-Programme of the European Commission and is funded by the EC Joint Research Centre (JRC). The consortium for the VISPA development consists of the IfEN GmbH (coordinator) and the AGIS Institute of the University FAF Munich. For the development of the user requirements as well as for the later testing period support is given by the German Alpine Club (DAV). The schedule of the project is as follows: Start of the project was on 31. January 2001. The duration of the project will be 8 months. There are four main phases: System Definition: Definition of user requirements, scenario definition, system design PINA Server Development: Development of server software, GIS database adaptation, development of tour routing algorithms, generation of localized and personalized data TourGuide Development: Development of the User Interface, software integration, hardware integration of the mobile components Concept Demonstration:
Beta demonstration of the TourGuide (in-house), refinement phase, final demonstration at Spitzingsee (Bavarian Alps)
SYSTEM AND SERVICE DESCRIPTION System Overview and General Service Description
Especially in mountainous regions with a thin path-network, the user needs assistance by answering the following questions: Where am I? What is my location in a frame of reference that I can understand? Where is my destination? How can I get there? Does the proposed way hit my requirements regarding length, height differences etc.?
The Virtual Sports Assistant (VISPA) consists of the Service Provider component Personal Information and Navigation Assistant (PINA)-Server and the Mobile User component TourGuide-Device. Both together enable complete tour guidance for mountain walkers. The user sends requests for routing, tourist information etc. to the PINA Server; the server generates the relevant data according to the user request and sends them to the Tour Guide. The following figure outlines the overall VISPA system architecture.

GNSS GPS, GALILEO, GLONASS Terrestrial Broadcast Stations
Azimuth Sensor GSM, GPRS, UMTS

TourGuide

Database-System

PINA-Serve r

Inte rnet/LAN

VISPA Service Provider

Figure 1: VISPA System Architecture The user is equipped with the Mobile Device that consists of a mobile info-terminal, a satellite navigation receiver and a digital magnetic compass. The position is determined via GPS and an accurate orientation is given with an electronic compass. A positional accuracy in the range of 5-20 m is accessible since the US-DoD switched off the artificial dilution of precision (selective availability SA) in May of the year 2000.
The Mobile Device communicates via broadband-communication with the PINA-Server. Based on the positional information and additional user requests, the PINA-server provides the user with the following services.

Core Services

Navigation Service: The PINA server provides Geo-Information (2D-maps, 3D rendered images) on request according to the users current position. Three kinds of on-line tour routing services are offered by the PINA server: Start destination routing: the user selects start and destination point; the PINA server provides the appropriate route Routing to the nearest refuge: the PINA server provides the route to the nearest hut Lost-trail routing: the PINA server provides the route back to the nearest trail in case the user lost his trail Based on the received data the mobile device is capable of providing tour guidance information to the user. General Information Service: Additional personalized thematic data (Tourist data) is provided from the PINA-Server on request. This data contains e.g. the names and business hours of huts, the names and height data of mountain summits etc. The position of relevant points can be displayed in a map. A routing to these points can be performed and presented as described under Navigation Service. Extended Functionality Options: In addition to the service functions given above the implementation of extended functionality is possible (but not done within this project): Perform routing with constraints (duration of tour, severity of route etc.) Emergency call (including exact position of caller) Personalized tracking / Group tracking Weather forecast (forecast especially for the users location) Update functionality (user can add new information to the central database)
Depending on his requests the user will get the following types of information on his screen: 3D rendered terrain visualization of the surroundings Proposed path as line signature as visible in the terrain from his point of view Distance to the destination and to the next waypoint Direction to the destination and to the next waypoint Derivation of the orientation of the Mobile Device to the line of sight, presented with arrows (see Figure 6) Presentation of the proposed path with its waypoints in a map

Model-Description

As already outlined in chapter 3.1 the concept of VISPA is based on the interaction between the mobile device and the PINA server:

Mobile Device

Hardware
PDA Mobile phone GPS receiver Azimuth sensor
- C++ - Object oriented - Class structure

Request Response

Internet

Software

GSM/GPRS Air Comm. Interface

PINA Server

Hardware Software
- Typical - IIS / ASP workstation - C++ components - Data warehouse / database - Rendering engine
Figure 2: Logical/functional model of VISPA Using a cellular phone the mountaineer can connect to the Internet, which makes it possible to use standard Internet request via HTTP and standard data provision in XML format. UMTS is not yet available, so the General Packet Radio Service (GPRS) is used instead for the communication between mobile device and PINA server. As the user has to pay for the amount of transmitted data (independent of the time he was connected), he can stay always online. Figure 3 schematically shows the complete chain of communication between mobile device and server.
Figure 3: Client/Server Communication

Exemplary Scenarios

In the following some typical underlying scenarios in the usage of the VISPA are exemplarily described in brief: Start-Destination Routing: The user is on his starting point and has no definite idea of his destination - The user requests/receives hotspots (points of interest) from the PINA server. - For some of the hotspots, he is especially interested in, he requests/receives further information (e.g. name/height of a summit, name/business-hours of a hut). - Based on this information the user makes his decision about his final destination and requests the routing to the specified point. - The routing is performed on the PINA server and the result is transferred to the client. - The trail to the users destination is displayed on the mobile device together with some additional information (direction, distance). - The user is walking along the trail and can view his current position displayed in the map. Lost-Trail Routing: The user has lost his trail or just wants to know how to get to the nearest trail - The user sends a lost-trail-routing request to the PINA server. - The routing data is calculated on the PINA server and transferred to the client. - The route is displayed on the mobile device (as above). 3D-rendered Image: The user wants to get a 3D-rendered image with route overlay to compare it with the real situation for a better orientation - The user requests/receives a 3D rendered image according to his current position from the PINA server. - The derivation of the users line of sight is displayed. - The user turns to the displayed direction, until the derivation of the orientation is zero ( image matches the real terrain sight). The following figure gives a schematic overview of the client-server interaction for the routing scenario.

GPS-Receiver Digital Compass
Sensor Data - GPS-Position - Orientation

HTTP-Request

Search position and close region in the database - DTM - Routes - Maps X,Y dX - Info dY
Travel-Assistant (Core Terminal): - Display - Input device

User: RoutingRequest

Calculate routing to the next line of route network

HTTP-Response

Create 3D Visualization of the close region in line of sight to the proposed way
- 2D map, 3D-visualization as image - direction & distance to destination
Figure 4: Exemplary Routing Scenario
MOBILE CLIENT ARCHITECTURE AND SOFTWARE General Options
In principle one can think of several kinds of devices for the core terminal and the navigation-/ communication units (see Figure 5). There is a wide range of portable computers from notebooks up to organizers. As it is the aim of the VISPA project to provide the mountaineer with a compact and easy-to-handle mobile device a PDA was selected. For communication a GPRS cellular phone is necessary. There are only very few relevant models available at the moment. The final intention is to have a multi-mobile device, which combines the functionality of the PDA and the mobile phone. However, such so-called smart phones are not yet available off the shelf, respectively not appropriate to be used for the VISPA project. GPS receivers are available as separate handheld devices (to connect via serial cable) as well as plug-in modules for the PC card or CF card slots of the mobile computers.

GPS-Positioning

Teletype GPS

Communication

Interfaces

USB/LPT PCCard PCCard

Xircom Credit Card GPRS Ericsson R520 GPRS

Core devices

Emtac GPS Crux II

CF I/II

Bluetooth RS-232 IrDA
GeoDiscovery Geode GPS Modul (Handspring Visor)
Springboard RS-232 RS-232

Garmin eTrex

RS-232 RS-232

Siemens M35 (outdoor)

Precision Navigation TCMVR 50 Honeywell HMR 2300

Azimuth-Sensor

Figure 5: Integration Options of TourGuide Components

Final TourGuide Configuration
In Figure 6 the final configuration of the selected TourGuide hardware components and their corresponding communication interfacing is given.
e rn t h se nte d o tu e io n t e the pr ct Dire e to se e vic d in te rra

Orie io ntat

EMTAC Crux II GPS Positioning Sensor (CF I/F)

n of ile Mo b

IfEN/TCM 50 Azimuth Sensor (Serial I/F)
CASIO EG-800 Motorola GPRS Mobile Phone (IrDA I/F)

ic Dev e

Figure 6: Final TourGuide Configuration
4.2.1 Detailed Hardware Description Core Terminal: Pocket PC Casio EG-800 This is a high performance Pocket PC for industrial/outdoor use which offers full color graphics display (240 x 320 pixels) and extended interface capabilities: The IrDA Port is the interface to the communication unit, the Compact Flash card slot for the navigation unit. The digital compass is connected via the serial interface. The operating system is Windows for Pocket PC (Windows CE 3.0). Some relevant specifications: CPU: Memory: Battery life: Weight: VR 4122 (150 MHz) 32 MB up to 13 hours ca. 300 g
Communication Device: Motorola Timeport 260 The Timeport 260 is a tri-band cellular phone capable of combining 3 GPRS downlink channels. The connection to the PDA is done via the IrDA interface. Some relevant specifications: Talktime: Standby: Weight: minutes hours ca. 110 g
Heading Device: IfEN/TCM 50 Azimuth Sensor This 50 tilt-compensated compass device is assembled (housing) by IfEN GmbH and bases on the sensor TCM50 from Precision Navigation. It provides the heading (NMEA protocol) information with an accuracy of degrees. The TCM50 is connected to the PDA via the serial RS-232C interface. Navigation Device: EMTAC Crux II GPS Receiver Card This GPS card is a 12 channel GPS receiver that comes in a Compact Flash (CF) form factor suited to directly connect to the Pocket PC. The Crux II GPS receiver card has an in-built EGNOS/WAAS capability that allows for position accuracy improvement. 4.2.2 Software For the development of the Mobile Client software the MS embedded Visual C++ 3.0 together with the MS Pocket PC 3.0 Software Development Kit are used. This development environment has the same U/I as the standard MS Visual C++ IDE and allows it to emulate a Pocket PC on the desktop PC. On mobile client side four major software components are developed: - User interface: performs display and data-viewer tasks, dispatches commands etc. - Communication interface: manages the requests/responses to/from the server; interface to real external communication device - Navigation interface: decodes the positioning and heading information from the navigation HW - Application Logic: requests and manages map data, routes and points of interest
SERVER ARCHITECTURE AND SOFTWARE
In the following chapter the PINA (Personal Information and Navigation) server within the VISPA project is outlined. The main tasks of the PINA server are storing geoinformation, processing the request from the digital tour guide and providing the result in a suitable manner to the mobile client. The server consists of three major components. The first one is a communication interface that is responsible for receiving the request from the mobile device, calling the necessary functions for the geoinformation production and ensuring that the mobile client receives the results. The second component is the geoinformation production component. Depending on the kind of request the appropriate geoinformation in most cases related to the current location of the user are generated. To allow for this geoinformation production different kinds of data must be available. Therefore the third component of the PINA server is a data warehouse that manages all necessary data. Figure 7 shows an overview of the PINA server. In the following chapters those components will be described in more detail.

Figure 7: PINA server architecture

Communication Interface

To realize the communication between the mobile device and the PINA Server the http protocol, e.g. known from the World Wide Web, is used. The mobile device sends its request to the Web Server respectively the PINA server. Depending on the kind of request (perform routing, show a map, ) different ASPs with various parameters (location of user, desired destination) are called from the mobile device. The results of the request (heading, a map, set of waypoints, ) as well as the requests from the mobile client itself are transmitted using XML. The great advantage of using XML in both directions is providing a standard mechanism, which is an extendible and easy to access interface as XML parsers are available for nearly every programming language. The whole communication on server side between the mobile device and the PINA server is handled by the Microsoft Internet Information Server (IIS).
Components for Geoinformation Production
As not all necessary functionalities can be implemented using ASPs the Component Object Model (COM) is used to get access to C++ routines. Furthermore the use of C++ components ensures a better performance than ASPs as they use interpreted languages. Within VISPA most tasks that accrue during the production of the geoinformation are processed in C++. The mobile client can request maps, points of interest, factual information and images rendered from 3D data from the PINA server. The rendering engine is the key component to the perspective views generated from the DTM. Within VISPA POV-Ray has been chosen as rendering engine (see Figure 8b). Another important service provided by the PINA server is the routing functionality. As routing algorithm a conventional start-destination routing based on the routing data in the DBMS will be used.

Data Warehouse

Another major component of the PINA server is the data warehouse. It hosts all necessary data to allow for providing the services described in chapter 3.1. Depending on the type of data they are stored in different ways. Raster data, e.g. scanned maps are stored as images in a file structure. Vector data, e.g. the routing data are handled by a DBMS. In the following the different kinds of data and their usage in this project are described. DTM data The data basis for the DTM data is a 1 (~30.9m) grid covering the whole test area. To achieve a better visual appearance a 10m grid has been interpolated from the original data. The DTM data used are used in two cases of the geoinformation production: 3D rendered image The DTM data are the foundation to create 3D rendered images (perspective views). They are used to generate a so called height field within the
rendering engine, which allows for texture mapping of images (e.g. maps) or/and a calculated routes onto its surface. Determine visibility of poi The intent is to use the DTM data also to determine the points of interest visible from the current point of view. This is only necessary in the case the user request a perspective view (3D rendered image) from the PINA server.

Scanned maps This kind of data are tiled conventional topographic maps in different scales. The tiling contributes towards minimizing the amount of data transferred between the PINA server and the client as only the necessary tiles are send to the client. The scanned maps are used in two major categories of geoinformation production in this project. On the one hand they provide maps in different levels of detail to the client. On the other hand they are texture mapped onto the DTM to allow for an easier to interpret 3D rendered image. Routing data The routing data are a mesh of hiking trails and points of interest like huts or mountaintops. Furthermore each edge or node of the trail network has additional information like severity or object class. This allows for using the data not only as a basis for the routing, they also can be used to provide points of interest.
CONCLUSIONS First Results and Experiences
The following two figures show some very early examples for the information provided to the user in order to support his navigation and orientation tasks. Figure 8a shows a sample for a two-dimensional, traditional map (user position and path not yet indicated at this stage). Figure 8b shows an example for an image rendered from DTM data. A map and a proposed route are texture mapped onto the DTM.
Figure 8 a,b: 2D-Map; Image rendered from DTM data
With respect to practical experiences gained through the work with the connection and configuration of the necessary VISPA hardware, the following two main issues have been identified: The communication between PDA and hardware components (GPS Receiver, electronic compass, mobile phone) turned out to be quite difficult due to interfacing issues (hardware and software level). Meanwhile these problems have been widely solved. At present, the transfer-rates on GPRS data link are low and do not yet correspond to the announced rates. However, an increase of the data rates may be expected as soon as GPRS will finally be well established.
Conclusions and Perspectives
The presented VISPA concept gives the mountaineer a deep confidence in the activities he is actually performing. This ensures high acceptance of the service (also if it has to be paid for in a later fully operable version), but also should create additional tourist attraction for this sport having such an innovative system at hand. Furthermore the core services are the essential part for safety-of-life issues to prevent the outdoor activists from critical situations. Loosing the trail can often cause dangerous situations for the mountaineer. Having the possibility to be guided back to a safe trail means a strong enhancement of the users safety. There are of course several possible options for extended service functionality as mentioned in 3.2. Some of these functions will be implemented by the project PARAMOUNT, anticipated to be funded by the European Commission within the IST-Programme under Cross Programme Action 3. Besides a more compact configuration of the TourGuide hardware will be possible, when the first suitable smart-phones will be available. E.g. the Siemens SX 45 Multimoble is announced to be available in August 2001. This Pocket PC contains an integrated GPRS phone, which means a strong enhancement of the mobile device handling. This will be at least one step to the aim of the ideal user system, i.e. having just one single device. Another enhancement for the handling will be the GPS device with built-in antenna, available about in July 2001.

ACKNOWLEDGEMENTS

The authors acknowledge the support and co-operation of the European Commission Joint Research Centre (JRC) in Ispra / Italy, which is funding the VISPA project under contract number 17166-2000-12 F1SC ISP DE. The authors also like to thank the German Alpine Club (DAV) for supporting this project by sharing the knowledge in the field of sport activities in mountainous regions during the scenario definition and test phase of VISPA.

REFERENCES

Some recent publications of IfEN GmbH on GNSS and GSM/UMTS: Balbach, O., UMTS Competing Navigation System and Supplemental Communication System to GNSS, Proceedings of the ION 2000, Salt Lake City, UT, Institute of Navigation, September 2000 Hein, G. W., Eissfeller, B., Oehler, V. and Winkel, J. O., Synergies Between Satellite Navigation and Location Services of Terrestrial Mobile Communication, Proceedings of the 13. International Technical Meeting, Salt Lake City, UT, Institute of Navigation, September 2000 Winkel, J. O. and Eissfeller, B., Modelling and Simulating GNSS Signals and Receiver in Arbitrary Environments, GNSS 1999, Genoa, Italy, Italian Institute of Navigation, October 1999 Some recent publications of AGIS: Caspary, W., Msbauer, M., AIDA-Multimedia Alpine Guide Italia. Deutschland. Austria, Hochgebirgskartographie, Silvretta '98, Wiener Schriften zur Kartographie, Vol. 11, PP. 169-173, 1998 Caspary, W., Joos, G. and Msbauer, M., Multimedia und mobile GIS, Zeitschrift fr Vermessungswesen, Vol. 125, PP. 272-279, 2000 Koppers, L., 3D-Map - Virtual Reality and Geo-Data, EOGEO 98, Tagungsband Universitt Salzburg, 1998. or online-paper: http://agis.bauv.unibw-muenchen.de/publix/koppers/eogeo/index.html Koppers, L., Schfer, S., Touren - Routing mit GIS - Ein neuer Ansatz des Seilanpassungsverfahren, GIS GEO-Informationssysteme , PP. 19-23, 1999 Leukert, K., Reinhardt, W., Seeberger, S., GIS-Internet Architekturen, Zeitschrift fr Vermessungswesen, Vol.125, No.1, PP. 23-28, 2000 Reinhardt, W., Geoinformationssysteme - Chancen in der Informationsgesellschaft, DVW Mitteilungsblatt, Vol. 51, No. 3 - 1999, PP. 249-264, 1999

EMTAC mini-S3 Bluetooth GPS GPS Receiver

User Guide

The mini-S3 pairing code is 0183.

Notice

We suggest that you carefully review the User Guide prior to using your GPS receiver. The mini-S3 BTGPS receiver is a highly sensitive piece of electrical equipment that can be easily damaged through misuse. In order to help you fulfill any warranty obligations, read the User Guide in its entirety. The mini-S3 passkey is 0183.
Congratulations on your purchase of the mini-S3 BTGPS!
The mini-S3 is an excellent navigation and positioning aid when used with a Bluetooth enabled host device and GPS application software. Your package should contain the mini-S3 BTGPS Receiver, car charger, AC (wall) charger, lanyard, and a product CD containing this manual and the Crux-View test software.

Utilizing the User Guide

This User Guide is an important part of the mini-S3 BTGPS. Reading the User Guide will help you get the best performance from your receiver. In addition to helpful operating information, the User Guide brings attention to potential safety concerns and warranty obligations regarding the receiver. The mini-S3 BTGPS Receiver is a highly sensitive piece of electrical equipment that can be easily damaged through misuse. The warranty will not cover failure if the product is abused, misused or used for other than the intended purpose. Read all the information carefully to avoid damage to the GPS receiver. The mini-S3 pairing code is 0183.

Table of Contents

What You Need to Get Started Parts of the mini-S3 & What They Do Power Switch LED indicators Antennae faade Power Jack Power jack Battery Charger Getting Started Basic Use Guidelines Frequently Asked Questions Care & Maintenance How GPS Works Warranty Disclaimers & Liability Warnings Glossary 19 23
What You Need to Get Started

1. A Host Device

A Bluetooth enabled host device (i.e. PDA, smartphone, laptop, etc.) is needed to receive GPS input data. Each host device receives GPS input differently. Consult the instructions of your particular host device on how to enable your device to receive GPS input.
2. GPS or Mapping Software
Before you begin using your mini-S3 BTGPS Receiver you must complete the application software installation tasks on your host device. Different software programs configure the GPS input differently. Consult your softwares user manual to configure the software to accept GPS input. If you do not have mapping software, in this User Guide CD-ROM, there is the Crux-View Test Program (trial version) for testing purpose. Please follow the step-by-step operation guide indicated and described in the Crux-View (Trial) Manual file (in.pdf format). This will give you the basic GPS information needed to proceed. Note: The Crux-View Test Program is helpful to have installed if you need additional technical support. Note: (a) The Crux-View Test Program is a trial version program and is available only for testing purposes. (b) The Crux-View program is only to be used with EMTAC BTGPS units. (c) The Current version of Crux-View supports ARM (StrongARM/X Scale) based PPC.
3. The mini-S3 BTGPS Receiver
The mini needs to be fully charged prior to using it for the first time. CAUTION: Use only an EMTAC branded charger with the mini to charge the receiver. Use of other chargers can result in failure of the unit and/or its Lithium-ion battery.
Parts of the mini-S3 BTGPS Receiver & What They Do
mini-S3 BTGPS at a Glance

Antenna Facade

LED Indicators

Power Switch

Power Jack
Slide the switch sideways to turn power on and off. represents power ON represents power OFF

Status LED Indicators:

Orange/Red Green
Switch to power-on position:

The three LED lights indicate the operational status of Bluetooth, GPS, and battery. Symbol: Blue LED Light indicates Bluetooth pair/connect status
Flashing every 1 second: mini-S3 powered-on and waiting to pair/connect. Flashing every 2 seconds: mini-S3 is connected and paired with the host.

Symbol:

Green LED Light indicates GPS status mini-S3 is powered on, attempting a location fix. mni-S3 has a location fix.

Constant on: Flashing:

Orange /Red LED Light indicates Battery status
Red light constant on: Battery low. Orange light constant on: Battery under charging. No light (light off): Battery fully charged

Antenna Faade

Your mini-S3 is integrated with a highly sensitive internal 1.5GHz GPS antenna and a 2.4GHz Bluetooth radio. These internal components provide satellite signal reception for position fix as and data communication between the mini-S3 and your Bluetooth enabled host device. The antenna facade is the top surface of the mini-S3. Keep this surface clean and with an unobstructed view to the sky while operating the mini-S3. CAUTION: Do not cover the antenna faade with any object containing metal and/or electromagnetic wave absorption material such as: screwdrivers, pens, watches, floppy diskettes, CDs and metal wires, aluminum foil and metal-coated plastic bags, water or liquids, and/or carbon paper.

Antennae Facade Area

The power jack enables you to connect the receiver to the charger and re-charge the Lithium-ion battery. The mini-S3 may be used while plugged into a power source and at the same time charge the battery. CAUTION: Use only EMTAC branded chargers with the mini-S3 to charge the receiver. WARNING: Use of other chargers can result in failure of the unit and/or its lithium-ion battery.

Charger Plug

Charger
The charger connects the mini-S3 Receiver to a power source so the battery can be re-charged. The mini-USB plug of the charging cord connects to the mini-S3 via the power jack while the large end of the charger connects to the power source. The mini-S3 may be used while plugged into a power source while charging. CAUTION: Use only EMTAC branded chargers with the mini-S3 to charge the receiver. WARNING: Use of other chargers can result in failure of the unit and/or its lithium-ion battery.

Battery

The mini-S3 contains a removable, rechargeable Lithium-ion battery which supplies the power for the operation of the GPS and Bluetooth circuits inside the receiver. It is a low consumption battery with a minimum of 8 hours of continuous use after fully charged. The battery can be recharged using the EMTAC branded charger which came with the mini-S3. The mini-S3 may be used while the battery is being charged. To remove the battery, slide the battery cover away from the device, then remove the battery. CAUTION: Use only EMTAC branded chargers with the mini-S3 to charge the receiver. WARNING: Use of other chargers can result in failure of the unit and/or its lithium-ion battery. WARNING: Do not open the unit other than to replace the battery. There are no serviceable parts inside. WARNING: Exposure to temperatures greater than 60C (140F) will damage the battery and poses a risk of explosion. See WARNINGS on pages 22 - 23 for more extensive safety information on the battery.

Frequently Asked Questions
Which GPS/Map application software can I use? There are a lot of major application software packages available. The mini-S3 will work with any mapping software that uses the industry standard NMEA messages. For laptops and Window Mobile devices, we recommend CoPilot Live from www.alk.com. For the Palm OS, we recommend the EMTAC Navigator Palm OS software. Can I use the Crux-View for navigation purpose? No. The Crux_View Test Program is only for evaluation and for testing purposes only; it is NOT designed for navigation. What is the passkey or pin code for the mini-S3 paring with the PDA? Please key-in: 0183. This the passkey or the pin code required. I have already paired the mini-S3 BTGPS Receiver with the PDA, but sometimes it just cannot connect to the mini-S3. Delete the old BTGPS icon on your Bluetooth manager software, and re-search and pair it again. It is possible to charge the battery and at the same time use the mini-S3? Yes. This means you can have continuous use of the mini-S3 BTGPS Receiver. The GPS program is not showing my location. If the green light on the mini-S3 is flashing, check to see that you have the correct COM port and baud rate selected (4800-38400) and that your device is paired with the mini-S3. If the green light is not flashing, position the receiver so that it has an unobstructed view of the sky. If the green light is not flashing after being outside for more than fifteen minutes, please contact technical support. The green light on my mini-S3 BTGPS will not come on. Remove the unit from external power source. Turn unit on and let the batteries drain for 24-48 hours. After 24-48 hours, fully charge the mini-S3 and turn on. If green light is still off, please contact Technical Support for more information. The blue light on my mini-S3 BTGPS will not come on. Please contact Technical Support for more information. Additional FAQ, technical support and new product information can be found at www.EMTAC.com.

Care and Maintenance

Your mini-S3 BTGPS receiver is a highly sophisticated piece of electrical equipment which requires special care and maintenance. Please follow the suggestions below to fulfill any warranty obligations and ensure you get the best performance possible from your mini-S3.

Keep the mini-S3 BTGPS receiver dry. Exposure to rain and/or environments with high humidity will cause the receiver to malfunction and create irreversible damage. Precipitation, humidity, and other liquids contain minerals that can corrode the electronic circuit boards as well as the connector, jack, and plug. Protective cases are available for the mini-S3. Please contact your retailer for more information. Use/store the mini-S3 at a temperature between 15C (59F) & 25C (77F). Exposure to extreme hot or cold conditions, such as a closed car in summer or winter, will affect the performance of the receiver and reduce both the capacity and lifetime of the battery. When not in use, store the receiver in a clean environment. If left in an unclean environment, dirt and dust can enter the circuit board and damage the receiver. Clean with a soft, dry cloth. Use of harsh cleaning solvents, chemicals or strong detergents will damage the receiver. Use only EMTAC branded chargers to charge the mini-S3 receiver. Use of any charger other than the one provided may damage the S3 and create the risk of explosion. Use only accessories approved for use with the mini-S3. Unauthorized accessories, antenna, modifications or attachments can damage the S3, may void warranty, and violate regulations governing radio devices. Keep the mini-S3, battery, battery cover and all accessories out of small childrens reach.
Hit, drop, or shake the mini-S3. Rough handling can break the internal electronic circuit boards, the connector, and/or the power jack resulting in irreversible damages and unit malfunction. Store or expose to temperatures higher than 60C (140F). High temperatures, such as in a car under direct sunlight, can shorten the life of electronic devices, and melt or drape certain plastics. Store or expose to temperatures lower than 0C (32F). Extreme temperatures affect the performance the battery. In addition, when the receiver warms up to its normal operation temperature, moisture can condense inside it, which may severely damage electronic circuit boards inside. Attempt to open the mini-S3. There are no serviceable parts inside the mini-S3. Unauthorized handling will void the warranty and may damage the receiver. Paint the mini-S3. Paint can clog the connector, jack, and prevent proper normal operation of the receiver.
How the mini-S3 BTGPS Works
The Global Positioning System (GPS) is a space-based radio-navigation system. This system consists of 24 satellites, which orbit the Earth at an altitude of approximately 17,500 kilometers. Each of the 24 satellites is deployed in 6 orbital planes and circles the earth twice a day. These systems of satellites continuously transmit signals containing precise information, 24 hours a day in any weather condition, everywhere around the world. By processing the signals received, the mini-S3 BTGPS receiver provides users with helpful information of position, velocity, and time for navigation and location based services anytime, anywhere on the Earth. The time it takes the GPS to find the satellites is called the Time to First Fix (TTFF). The GPS receiver needs to lock on to at least 3 satellites for a position fix. The mini-S3 BTGPS Receiver acquires a position fix typically within 10 seconds from a hot-start state and roughly 80 seconds from a cold-start state. The initial state of the receiver, (i.e. the latest status in the memory of the receiver) primarily determines the time of TTFF. If you have not used your GPS unit for several months, the almanac data for the satellites may be out of date. The unit is capable of recollecting this information on its own, but the process can take as long as 3 to 5 minutes. The TTFF will also be longer the very first time the user first turns on the GPS receiver, when a GPS receiver has lost memory, or has been moved over 300 miles (500 km) from its last location will also be longer. Both TTFF and positional accuracy can be affected by obstructions such as tall buildings, narrow streets & passageways, protective film on glass, heavy foliage, large cliffs, and other situations where GPS satellite signals are blocked. Once there is a position fix, the mini-S3 uses the satellite signals to calculate an exact geodetic location through triangulation method, contained in 10 meters CEP accuracy devoid of Selective Availability (SA). The position data is then converted within the receiver to latitude and longitude coordinates, which is usually provided in the geodetic datum on which GPS is based (WGS 84). The map datum selected on a GPS receiver needs to match the datum listed on the corresponding paper map in order for the position readings to match. Using the wrong datum can result in position offsets of hundreds of meters or much more. In addition to using the wrong datum, accuracy can be limited by satellite orbiting errors, multi-path signals, atmospheric delay and receiver clock timing.

Transplant GPS, Inc. Limited Warranty
HARDWARE: Transplant GPS, Inc. warrants to the original end user (ie. Customer) that this product will be free from defects in workmanship and materials, for one year from the date of original purchase from Transplant GPS. The provisions of this warranty shall not apply if, in Transplant GPSs judgment, the product has been subject to misuse or neglect, improper installation, damaged in an accident, or repaired or altered in any way that adversely affects its performance and reliability. Transplant GPSs sole obligation under this express warranty shall be, at Transplant GPSs option, to replace the product or part with a comparable product or part, repair the product or part, or if neither repair nor replacement is reasonably available, Transplant GPS may, in its sole discretion, refund to Customer the purchase price paid for the product or part. Replacement products or parts may be new or reconditioned. Transplant GPS warrants any replaced or repaired product or part, and any hardware upgrade to which Customer is entitled under an agreement between Customer and Transplant GPS, for a period of ninety (90) days from shipment, or through the end of the original warranty, whichever is longer. All products or parts that are replaced become the property of Transplant GPS. This warranty does not cover products sold AS IS or WITH ALL FAULTS.
OBTAINING WARRANTY SERVICE: Customer must contact Transplant GPS within the applicable warranty period to obtain warranty service authorization. Dated proof of original purchase from Transplant GPS or its authorized reseller will be required. Transplant GPS is not responsible for Customer products or parts received without a warranty service authorization. Products or parts shipped by Customer to Transplant GPS must be
sent prepaid and packaged appropriately for safe shipment, and it is recommended that they be insured or sent by a method that provides for tracking of the package. THIS WARRANTY SHALL NOT BE EXTENDED, ALTERED
OR VARIED EXCEPT BY A WRITTEN INSTRUMENT DULY SIGNED BY TRANSPLANT GPS, LLC. WARRANTIES EXCLUSIVE. IF THIS PRODUCT DOES NOT OPERATE AS WARRANTED ABOVE, CUSTOMERS SOLE REMEDY FOR BREACH OF THAT WARRANTY SHALL BE REPLACEMENT OR REPAIR OF THE PRODUCT OR PART OR REFUND OF THE PURCHASE PRICE PAID, AT TRANSPLANT GPSS DISCRETION. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES (OR CONDITIONS), EXPRESSED OR IMPLIED, INCLUDING (WITHOUT LIMITATION), ANY WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT, OR FITNESS FOR A PARTICULAR PURPOSE. TRANSPLANT GPS SHALL NOT BE LIABLE FOR LOSS OF PROFITS OR ANY SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES WHICH THE PURCHASER MAY SUSTAIN. IN NO EVENT SHALL TRANSPLANT GPSS LIABILITY EXCEED THE PURCHASE PRICE OF THE DEFECTIVE PRODUCT. TRANSPLANT GPS NEITHER ASSUMES NOR AUTHORIZES ANY OTHER PERSON TO ASSUME FOR IT ANY OTHER LIABILITY IN CONNECTION WITH THE SALE, INSTALLATION, MAINTENANCE OR USE OF ITS PRODUCTS. TRANSPLANT GPS SHALL NOT BE LIABLE UNDER THIS WARRANTY IF ITS TESTING AND EXAMINATION DISCLOSE THAT THE ALLEGED DEFECT OR MALFUNCTION IN THE PRODUCT DOES NOT EXIST OR WAS CAUSED BY CUSTOMERS OR ANY THIRD PERSONS MISUSE, NEGLECT, IMPROPER INSTALLATION OR TESTING, UNAUTHORIZED ATTEMPTS TO OPEN, REPAIR, OR MODIFY THE PRODUCT, OR ANY OTHER CAUSE BEYOND THE RANGE OF THE INTENDED USE, OR BY ACCIDENT, FIRE, LIGHTNING, OTHER HAZARDS, OR ACTS OF GOD. THIS WARRANTY DOES NOT COVER PHYSICAL DAMAGE TO THE SURFACE OF THE PRODUCT, INCLUDING CRACKS OR SCRATCHES ON OUTSIDE CASING. THIS WARRANTY DOES NOT APPLY WHEN THE MALFUNCTION RESULTS FROM THE USE OF THIS PRODUCT IN CONJUNCTION WITH ACCESSORIES, OTHER PRODUCTS, OR ANCILLARY OR PERIPHERAL EQUIPMENT AND

TRANSPLANT GPS DETERMINES THAT THERE IS NO FAULT WITH THE PRODUCT ITSELF. THIS WARRANTY DOES NOT APPLY TO ANY MALFUNCTION OR FAILURE OF THE PRODUCT OR PART DUE TO ANY COMMUNICATION SERVICE CUSTOMER MAY SUBSCRIBE TO OR USE WITH THE PRODUCT.
LIMITATION OF LIABILITY: TO THE FULL EXTENT ALLOWED BY LAW, TRANSPLANT GPS ALSO EXCLUDES FOR ITSELF AND ITS SUPPLIERS ANY LIABILITY, WHETHER BASED IN CONTRACT OR TORT (INCLUDING NEGLIGENCE), FOR INCIDENTAL, CONSEQUENTIAL, INDIRECT, SPECIAL, OR PUNITIVE DAMAGES OF ANY KIND, OR FOR LOSS OF REVENUE OR PROFITS, LOSS OF BUSINESS, LOSS OF INFORMATION OR DATA, OR OTHER FINANCIAL LOSS ARISING OUT OF OR IN CONNECTION WITH THE SALE, INSTALLATION,
MAINTENANCE, USE, PERFORMANCE, FAILURE, OR INTERRUPTION OF THIS PRODUCT, EVEN IF TRANSPLANT GPS OR ITS AUTHORIZED RESELLER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, AND LIMITS ITS LIABILITY TO REPLACEMENT, REPAIR, OR REFUND OF THE PURCHASE PRICE PAID, AT TRANSPLANT GPSS DISCRETION. THIS DISCLAIMER OF LIABILITY FOR DAMAGES WILL NOT BE EFFECTED IF ANY REMEDY PROVIDED HERE-IN SHALL FAIL OF ITS ESSENTIAL PURPOSE.
DISCLAIMER: Some countries, states, or provinces do not allow the exclusion or limitation of implied warranties or the limitation of incidental or consequential damages for certain products supplied to consumers, or the limitation of liability for personal injury, so the above limitations and exclusions may be limited in their application to you. When the implied warranties are not allowed to be excluded in their entirety, they will be limited to the duration of the applicable written warranty. This warranty gives you specific legal rights which may vary depending on local law.
GOVERNING LAW: This Limited Warranty shall be governed by the laws of the State of Minnesota, U.S.A. excluding its conflicts of laws principles and excluding the United Nations Convention on Contracts for the International Sale of Goods.

FCC Statement:

This device complies with part 15 of the FCC rules. Operation is subject to the following two
conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Caution: Changes or modifications not expressly approved by the party responsible for compliance could void the users authority to operate the equipment. Changes or modifications made without written approval may void the users authority to operate this equipment.
Disclaimer and Limitation of Liability
Transplant GPS and its subsidiaries assume no responsibility for any damage or loss resulting from the use of this product, software and User Guide. Transplant GPS and its subsidiaries assume no responsibility for any loss or claims by third parties which may arise through the use of the software. Transplant GPS and its subsidiaries assume no responsibility for any damage or loss caused by deletion of data as a result of malfunction, dead battery, or repairs. Under no circumstances shall Transplant GPS and its subsidiaries be responsible for any loss of data or income or any special, incidental, consequential or indirect damages however caused. The contents of this User Guide are provided as is. Except as required by applicable laws, no warranties of any kind, either express or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose, are made in relation to the accuracy, reliability or contents of this User Guide. Transplant GPS reserves the right to revise this User Guide or withdraw it at any time without prior notice. Transplant GPS reserves the right to make changes and improvements to any of the products described in this User Guide.

Copyright

Transplant GPS 2006. All rights reserved.
Reproduction, transfer, distribution or storage of part or all of the contents in this document in any form without the prior written permission of Transplant GPS is prohibited. The Bluetooth trademarks are owned by Bluetooth SIG, Inc. USA and used under license. Other products and company names mentioned herein may be trademarks or trade names of their respective owners. Transplant GPS reserves the right to make changes and improvements to any of the products described in this document without prior notice. Under no circumstances shall Transplant GPS be responsible for any loss of data or income or any special, incidental, consequential, or indirect damages howsoever caused.

Warnings

Care and Caution
The Global Positioning System (GPS) is operated by the United States Government which is solely responsible for the accuracy and continued operation of the system. Accuracy of position fixes (longitude, latitude and altitude) can be affected by alterations made to the GPS satellites by the U.S. Government. Accuracy is subject to change in accordance with the U.S. Department of Defense civil GPS user policy and Federal Radio Navigation Plan. Positional accuracy and time to fix time can also be affected by poor view of caused by obstructions such as tall buildings, heavy foliage, large cliffs and other obstructions where GPS satellite signals are blocked. The mini-S3 BTGPS does not substitute the needs of careful steering and good judgment. Never rely on a single tool or apparatus for positioning and navigation.

Accessories

Use only an EMTAC branded charger with the mini-S3 BTGPS receiver. Use of other chargers can result in failure of the unit and /or its Lithium-ion battery.

Software

The software supplied in and with the mini-S3 BTGPS receiver is solely for personal use. Copies may be made only for personal use. The software may not be copied, modified, reverse engineered or transferred unless expressively provided by written agreement. The software is the property of Transplant GPS and/or its supplier and is protected by international treaty provisions. Follow the operation guide as stated and described in the User Guide of the GPS application software.

Safety

The mini-S3 BTGPS contains Lithium-ion battery. For optimal battery capacity and life, keep the mini-S3 BTGPS between +15C (+59F) and +25C (+77F). Leaving the mini-S3 BTGPS in hot or cold conditions (e.g. a closed car in summer or winter conditions) will reduce the capacity and lifetime of the battery. The performance of Lithium-ion batteries is particularly limited in temperatures below 0C (+32F). A mini-S3 BTGPS with a hot or cold battery may temporarily not work, even when the battery is fully charged. Temperature extremes will also
affect the ability of your battery to charge. When operating in temperature extremes, allow the mini-S3 BTGPS to cool down or warm up prior to charging. Charge the mini-S3 BTGPS only with the supplied charger. When a charger is not in use, disconnect it from the power source. Do not leave the mini-S3 BTGPS connected to a charger for longer than 24 hours; excessive charging may shorten its life. If left unused, a fully charged battery will discharge itself over time. Batteries must be recycled or disposed of properly. Batteries must not be disposed of in municipal waste.
DO NOT DISPOSE OF THE mini-S3 BTGPS RECEIVER IN A FIRE!
CAUTION RISK OF EXPLOSION IF BATTERY IS REPLACED BY AN INCORRECT TYPE. DISPOSE OF USED BATTERIES ACCORDING TO THE INSTRUCTIONS.
To assure product safety, the battery maker requests following the statements be included in the instruction manual/User Guide of the equipment. Danger
When charging the battery, use dedicated chargers. Use the battery only in the specified equipment. Dont connect battery directly to an electrical outlet or cigarette lighter charger. Dont heat or throw battery into a fire. Dont use or leave battery close to fire or inside of a car where temperatures may be over 60C. Also dont charge/discharge in such condition. Dont immerse, throw, or wet battery in/with water / seawater. Dont put batteries in your pockets or a bag together with metal objects such as necklaces, hairpins, coins, or screws. Dont store batteries with such objects. Dont short circuit the (+) and (-) terminals with other metals. Dont place battery in a device with the (+) and (-) in the wrong way around. Dont pierce battery with a sharp object such as a needle, etc. Dont hit with a hammer, step on, throw, or drop to cause strong shock. Dont disassemble or modify the battery. Dont solder a battery directly. Dont use a battery with serious scar or deformation. Dont use battery in a corrosive environment (damage from salt water, sea water, acid, alkali, corrosion gas, etc.).

Warning

Dont put battery into a microwave oven, dryer, or high-pressure container. Dont use battery with dry cells and other primary batteries, or batteries of a different package, type, or brand. Stop charging the battery if charging isnt completed within the specified time. Stop using the battery if abnormal heat, odor, discoloration, deformation, or abnormal conditions are detected during use, charge, or storage. Keep away from fire immediately when leakage or foul orders are detected. If liquid leaks onto your skin or cloths, wash well with fresh water immediately. If liquid leaking from the battery gets into your eyes, dont rub your eyes, wash them well with clean water and go to see a doctor immediately.

Caution

Store batteries out of reach of children so that they are not accidentally swallowed. Before using the battery, be sure to read the users manual and conditions on handling thoroughly. Thoroughly read the users manual for the charger before charging the battery. For information on installing and removing from equipment, thoroughly read users manual for the specific equipment. Batteries have life cycles. If the time that the battery powers equipment becomes much shorter than usual, the battery life is at an end. Replace the battery with a new battery of the same type. Remove a battery whose life cycle has expired from equipment immediately. When the battery is thrown away, be sure it is non-conduction by applying vinyl tape to the (+) and (-) terminals. When not using a battery for an expanded period, remove it from the equipment and store in a place with low humidity and low temperature. While the battery is charged, used and stored, keep it away from objects or materials with static electric chargers. If the terminals of the battery become dirty, wipe with a dry cloth before using the battery.
AC-DC Adapter The power supply Certified EINGANG/INPUT: 100-240VAC 50-60Hz 200mA AUSGANG/OUTPUT: 5.0VDC 1000mA Standard: EN60650 Battery Lithium Ion Rechargeable Battery Pack 3.7V 700mAh Cell Type: LP053436A Pack Model Name: NP40 Manufacturer: BYD Company Limited
Additional Battery Warnings
1. Do not put the battery into a fire, or heat the battery, do not store the battery in high temperature environment. 2. Do not connect the battery reversed in positive (+) and negative (-) terminals in the charger or equipment. 3. Do not let the battery terminals (+ and -) contact a wire or any metal (like a metal necklace or a hairpin) with which it carried or stored together, may cause short-circuit. 4. Do not drive a nail in, hit with a hammer, or stamp on the battery, do not strike the battery in other ways. 5. Do not disassemble or alter the batteries' outside structure. 6. Do not submerge the battery in water, do not wet the battery when store the battery. 1. Battery should be charged and discharged with proper charger, in compliance with correct operation contents. 2. Do not use the battery with other maker's batteries, different types and /or models of batteries such as dry batteries, nickel-metal hydride batteries, or nickel-cadmium batteries, or new and old lithium batteries together. 3. Do not leave the battery in a charger or equipment if it generates an older and/or heat, changes color and/or shape, leaks electrolyte, or cause any other abnormality. 4. Do not discharge the battery continuously when it is not charged. 1. In case young children use the battery, instruct them on the contents of the instructions and ensure the battery is correctly used by them at all times. 2. The battery was inspected carefully by QA before shipment to confirm with the specifications. However, in the case any abnormality of bad smell or heat, etc, arise after purchase, bring it and communicate with us. 3. For long-term storage, please charge at 0.5C for about one hour in advance. 4. Do not use the battery in other than the following conditions, otherwise, the battery might cause heat generation, damage, or deterioration of its performance. Operating environment: Charge : 0 - +45 - +60 - +60 - +45 - +25 Discharge : -20

Store less than 1 month : -20 Store less than 3 months : -20 Store less than 1 year : -20

Glossary

Almanac data A set of information that transmitted by each GPS satellite in orbit and the state of every satellite in the GPS constellation. Each GPS satellite contains and transmits the almanac data set for the entire GPS satellite system network. Almanac data allows the GPS receiver to rapidly acquire satellites shortly after it is turned on. Active Antenna An antenna that amplifies the GPS signal before it sends it to the receiver. Altitude The distance between the current position and the nearest point on WGS 84 reference ellipsoid, usually it is expressed in meters or feet and is positive outside the ellipsoid. Baud Bits per second. Also referred to as a baud rate. Channel Channel refers to a set of hardware in the receiver that detects locks on and continuously tracks the signal from a single GPS satellite. The more channels available, the greater number of GPS satellites signals a receiver can simultaneously lock and track. A receiver of 12 channels is the optimized design, considering the current consumption, chip-package size and cost. CEP - Circular Error Probable CEP is the radius of a circle, centered at a true location, within which fifty percent of positioning solutions fall. CEP is used to achieve horizontal accuracy. C/No Carrier-to-Noise density ratio. An indication of satellite signal strength received by the GPS receiver. Cold Start A condition in which the GPS receiver can arrive at a navigation solution without initial position, time, current Ephemeris, and almanac data. Constellation Constellation refers to the specific set of orbiting GPS satellites system, used in calculating positions or all the satellites visible to a GPS receiver at one time. The pattern created by the relative positioning of a GPS satellite network is designed to achieve a very high probability of global satellite coverage even in the event of satellite outages. dB
Decibel. A notation of relative unit such as the satellite signal strength received. Datum A math model which depicts a part of the surface of the earth. Latitude and longitude lines on a paper map are referenced to a specific map datum. The map datum selected on a GPS receiver needs to match the datum listed on the corresponding paper map in order for the position readings to match. Elevation mask Elevation mask is an adjustable feature of GPS receivers that specifies a satellite must be a certain number of degrees above the horizon before its signals are used for positioning. Satellites at low elevation angles (five degrees or less) have lower signal strengths and are more prone to loss of lock thus causing noisy solutions. Ellipsoid A geometric surface which all of whose plane sections are either ellipses or circles. Ephemeris Ephemeris is a set of parameters used by a global navigation satellite receiver to predict the location of a satellite and its clock behavior. Each satellite contains and transmits ephemeris data about its own orbit and clock. Ephemeris data is more accurate than the almanac data but is applicable over a short time frame from four to six hours. Ephemeris data is transmitted by the satellite every 30 seconds. The predictions of current satellite position are transmitted to the user in the data message. Geodetic coordinate A coordinate system whose elements are latitude, longitude and geodetic height. The latitude is an angle based on the perpendicular to the ellipsoid. Longitude is the angle measured in the XY plane.

GIS (Geographic Information System) A computer based system that is capable of collecting, managing and analyzing geographic spatial data. This capability includes storing and utilizing maps, displaying the results of data queries and conducting spatial analysis. Hot Start Start mode of the GPS receiver when current position, clock offset, approximate GPS time and current ephemeris data are all available.
L1 frequency 1575.42 MHz GPS carrier frequency which contains only encrypted P code, used primarily to calculate signal delays caused by the ionosphere. Latitude A north/south measurement of position perpendicular to the earth's polar axis. Longitude An east/west measurement of position in relation to the Prime Meridian, an imaginary circle that passes through the north and south poles. Multipath Multipath is the reception of a signal both along a direct path and along one or more reflected paths. Multipath signals result in an incorrect pseudorange measurement. NMEA (NATIONAL MARINE ELECTRONICS ASSOCIATION) A U.S. standards committee that defines data message structure, contents, and protocols to allow the GPS receiver to communicate with other pieces of electronic equipment aboard ships. Selective Availability (SA) Selective Availability is a process whereby the U.S. Department of Defense dithers the satellite clock and/or broadcasts erroneous orbital ephemeris data to create a pseudorange error to prevent adversaries from using the extremely accurate GPS positioning data. Spread Spectrum The received GPS signal is wide bandwidth and low power. The L-band signal is modulated with a pseudo random noise code to spread the signal energy over a much wider bandwidth than the signal information bandwidth. This provides the ability to receive all satellites unambiguously and to give some resistance to noise and multipath. Time To First Fix (TTFF) The time it takes to find the satellites is called the Time to First Fix (TTFF). If you have not used your GPS unit for several months, the almanac data for the satellites may be out of date. The unit is capable of recollecting this information on its own, but the process can take several minutes. The time it takes after the user first turns on the GPS receiver, when a GPS receiver has lost memory, or has been moved over 300 miles from its last location. TRIANGULATION A method of determining the location of an unknown point, as in GPS navigation, by using the laws of plane trigonometry.

Universal Time Coordinated (UTC) UTC is the time as maintained by the U.S. Naval Observatory. Because of variations in the Earth's rotation, UTC is sometimes adjusted by an integer second. The accumulation of these adjustments compared to GPS time, which runs continuously, has resulted in an offset between GPS time and UTC. After accounting for leap seconds and using adjustments contained in the navigation message, GPS time can be related to UTC within 20 nanoseconds or better. Greenwich Mean Time (GMT) is still the standard time zone for the prime meridian (zero longitude). Warm Start Start mode of the GPS receiver when current position, clock offset and approximate GPA time are input by user or by the application software. Wide Area Augmentation System (WAAS) Developed by the United States government, WAAS is a Satellite-Based Augmentation System (SBAS) that calculates the errors in the GPS signal at several monitoring stations around the country, then transmits error correction messages from geostationary satellites to GPS receivers. World Geodetic System 1984 (WGS 84) The primary map datum used by GPS. Secondary datums are computed as differences from the WGS 84 standard. WGS 84 is a set of U.S. Defense Mapping Agency (DMA) parameters for determining global geometric and physical geodetic relationships. Parameters include a geocentric reference ellipsoid; a coordinate system; and a gravity field model. GPS satellite orbital information in the navigation message is referenced to WGS 84. Almanac is retained, but ephemeris data is clear.