GPS systems (PDAs software and applications)

GPS tracking is entering most of the popular mobile platforms, including mobile phones, PDAs, media players, and game consoles. The attached figure is a PSP with new released GPS module. It is a good reason that kids can use to convince parents to buy a PSP for them.
It is difficult to mention all of the amazing GPS applications in the world. Here we summary the hottest GPS applications in the following list. And we try to offer some open source projects so anyone can use them as starting point.
A lot of applications in our daily life have already used GPS technology for years. Some applications operate independently, such as navigation, geo-tagging and passive track logger. The other applications connect to the complementary web servers for map tiles access, local search services, landmarks sharing and routes planning. GPS is entering most of the popular mobile platforms, including mobile phones, PDAs, media players, and game consoles. The attached figure shows a PSP with new released GPS module. It is a good reason for kids to convince parents to buy a PSP for them.

It is difficult to involve all of the amazing GPS applications. Here I summary the popular GPS applications in a list. And I try to offer some open source projects so anyone can use them as starting point.

1. Automotive Navigation: It is a typical application for GPS. Now it integrates more features including MP3/MP4 playback, DVB receiver, parking radar, and FM transmitter for voice guidance.
2. Personal Navigation: The personal navigation is available on the mobile phones and PDAs. It is a highly competitive market.
3. Tracking: It is yet another commercial application for tracking anyone and anything. The tracking services are used in seniors and children caring, pet tracking, fleet management, express delivery service and emergency positioning.
4. Traffic Management: Traffic management is a good idea to guide the drivers on the road to avoid traffic jams and accidents.
5. Location Based Services: It is the favorite word of mobile network operators. Actually LBS is a general terminology of mobile phone oriented value-added geographic services including navigation, local search and advertisement. LBS includes GPS and many other mobile networking based positioning technologies, such as GPSone, A-GPS, PHS positioning and Cell-ID positioning.
6. Mobile Social Network: It is a mobile version of the popular social network with location services. You can use it to check if your friends happen to cross in your road and check the upcoming events nearby. Check Loopt (Live Virtual Earth based) for Android and GyPSii (Google Map based) for iPhone. These networks are growing so fast and many VCs are trying to find such startup companies.
7. Geo-tagging: More and more pictures and videos are geo-tagged and shared on the web. Some new cameras have embedded GPS module to meet the requirement. It is interesting that these GPS enabled cameras also offer entry level personal navigation for the consumers. See, too many players are fighting for the same market.
8. Clock Synchronization: It used to be very expensive to keep the accuracy of a clock. Thanks to GPS’ clock system, the applications require clock synchronization can get the accurate clock signal from a low cost GPS receiver.
9. Location Intelligence for government and business organizations: A lot of organizations are using GPS for government operations and commercial intelligence investigation. For example, a supermarket company can use it for analysis of competition, customer purchase capability, rush hours, and resident favorite routes before launch a real supermarket there.

Navigation

Openmoko is the open source mobile phone project. This project is sponsored by FIC, a Taiwan based PC main board supplier. Openmoko’s latest model is NEO FreeRunner, which is an A-GPS mobile phone offers personal navigation.

It claims as the first 100% open source mobile phone, including the GSM stack. A powerful mobile Linux distribution is running on a 400MHz S3C2440 ARM920T CPU from Samsung. It features 2D/3D graphic, USB2.0, mini SD, Bluetooth 2.0, WiFi and A-GPS module.

It is a real hackers’ favorite toy. There is a hacker package available, including a NEO FreeRunner and a debug board. It should be the first candidate on your purchasing list if you are looking for a good GPS development platform. Everything is open for you.

The popular Dash Express is the first derivate project of Openmoko. This amazing device is a connected GPS, which allows the car drivers to share the real time traffic information and avoid traffic jams and accidents. Dash Express is the front-end of the whole aggressive project. This project uses web servers to collect the information of coordinates and velocity anonymously and broadcasts the road trend and traffic update to the drivers.

There is also a personal navigation program available in the Openmoko. The navigation software uses the map tiles from OpenStreetMap servers. It is much easier to access the map tiles from other free web geographic servers like Google, Live and Yahoo. However it may be forbidden in the terms and conditions. So the designer must check the legal terms of the map servers. Some projects already have big troubles of abuse the map servers. I have no idea about the capability of the web browser in Openmoko. If the web browser is JavaScript capable, the users can access Google Map for navigation.

Passive Tracking

The passive tracking is an off-line tracking technology by recording the coordinates during the whole trip. Passive tracking is commonly used in tracking services when real-time communication is not available or required. A wife may use it on her husband to check if he is cheating on her. The boss may use it to check the compliance of his delivery team. The scientists may track the birds for bird flu with a tiny track logger.

There are many open source projects for tracking purposes. Mr. Dana Peter has developed a web project online tracking service at Qcontinuum. The whole project is made up of a Bluetooth GPS module, a J2ME enabled mobile phone, and a web server. The source code of J2ME client software is opened for the public. And the JavaScript code in the web can be reused as well. However the back-end web pages involve user registration, mail, uploading, and format conversion have to be completed by an experienced web developer. I have ported Dana’s project to my own site at Ennovation. I reorganized the project to meet the requirement for Chinese people. And the Java code can be rebuilt on NetBeans IDE with slightly modification.

Since Google’s KML becomes the standard for geographic information exchange, many web sites and geographic software start to support track viewing with KML. The users can download the KML file from the GPS terminals and check it in Google Earth, OziExplorer, and World Wind of NASA. As alternative solution, the users can also upload to Google Map and Live Virtual Earth and view the tracks in the KML files online.

Real Time Tracking

The real-time track is a profitable market segment for the traditional GPS suppliers. A lot of organizations and individuals require real-time track services for tracking their assets in real-time. These organizations are express services, banks, security companies, car rental companies and car user clubs. The real-time tracking is the passive tracking plus the extra communication capability.

After 911, every mobile phone sold in US should have positioning capability. That creates anther market for personal tracking. Of course it brings up some arguments about privacy. After the massacre in Virginia Tech University, all of the college students especially the female graduates are told to carry the GPS phones, switch on the real time tracking and push the alarm key when necessary.

There are also some tailor-made terminals for the elder people and children, which are tracked by their families. Of course, more and more private cars are installed GPS based AVL (Automatic Vehicle Locator) anti-theft systems.

Although all of above real time tracking devices maybe have different names and outlooks, they share the same concept and system structure. An AVL is quite simple, one microcontroller with two serial ports, which connect to a communication module (GSM/GPRS/CDMA) and a GPS receiver module. The system controller will read the NMEA from the GPS and transmit via the communication module. The GPRS mode is preferred in a long time tracking project, rather than the SMS mode. An open source project called Open GPS Tracker uses a low-cost MOTO C168 mobile phone, Tyco A1035D GPS module and an AVR microcontroller to build an AVL. The total BOM cost is about 50USD.

Wavecom in France is a professional wireless communication module supplier, who offers various modules for GSM/GPRS/CDMA on different band. This company also deliveries combined modules with GPS inside. It is handy to develop and download your own code into the module via its Open-AT development tools. You can also purchase wireless communication modules from Cinterion (Benq-Siemens), Motorola, SIMCOM and Huawei. Wireless communication module has another popular name as M2M (Machine to Machine).

The Google Earth is powerful and popular. In general, it does not support track viewing with either local GPS over serial port or remote GPS over IP. Because its free version does not support communication with a GPS terminal. However, recently I realized that Google Earth is possible to check the web generated KML file regularly. In another word, the real-time tracking is possible on Google Earth, without any plug-in. I am planning to use this feature to build a real-time tracking service on my web server.

Traffic Management

Traffic management is the headache for the civil transportation management authorities. People are struggling with the traffic jam everyday. Up to now, at least in Shanghai, the traffic programs in FM radio are still the preferred source for the traffic update. It has a great value to allow the drivers on the go to have the overview insight for the traffic status ahead. TMC (Traffic Message Channel) is invented for this purpose. New delivery channels are emerging that could carry TMC services, including RDS/RDBS, digital radio (DAB), mobile Internet, paging and GSM/GPRS mobile phone networks.

The Dash Express GPS is a promising alternative solution for traffic management. Let us see it in this way. The TMC is a top-down and centralized traffic management approach, and the Dash Express is a flat and distributed traffic management approach. It is for sure that the similar projects will launch if Dash Express is successful.

Both TMC and Dash Express require powerful servers to collect the data of speed and vehicle densities on the road, and send the information back to the drivers via broadcast channels or IP networks.

Mobile Social Network

The social networks are invading mobile market. Since the biggest social networks have not consolidate their share in mobile world. A lot of startup companies announced mobile social networks because the concept is straight forward and easy to implement. GyPSii, a Dutch company is very successful in mobile social network on iPhone platform. We can expect that more similar applications will be available on Windows Mobile, Google Android. With Google’s expertise in Google Map and Google Earth and GPL, Android is the most promising platform. Let us pray Android phone can be released in 2008. In fact, Google's Android is a Java application environment. Google offers a complete API suite for it. However, Google forbids any other Java based applications to direct access its map tiles servers. Neither does MSN/Live and Yahoo.

Geo-tagging

The Flickr, Panoramio, and Google Picasa are popular because of the geo-tagging pictures. Some new cameras have embedded the GPS modules to meet the consumer requirement. The coordinates are usually written into the metadata area (EXIF) of each digital picture. So the consumers can upload the pictures and share with their friends seamlessly. The geo-tagging is a kind of passive tracking.

Geo-tagging brings revolution to the consumer electronics. The camera phones and digital cameras have GPS geo-tagging feature now. There are different solutions at this moment. One approach is connecting an external GPS logger to the shutter or flash light. The other approach is internal GPS, which offers coordinate to the application processor. Besides, I found some GPS suppliers are promoting some manual GPS loggers to record the coordinate for pictures. It is a less impressive and transitional idea, because everyone wants to carry less electronics during the journey.

Clock Synchronization

Even fairly accurate computer clocks are likely to vary due to manufacturing defects, changes in temperature, electric and magnetic interference, the age of the quartz crystal, or even system load. Additionally, even the smallest errors in keeping time can significantly add up over a long period.

The GPS system includes 24 satellites each with three or four on board atomic clocks. The US Naval Observatory monitors the satellite’s clocks and sends control signals to minimize the differences between their atomic clocks and a master atomic clock for accuracy and traceable to national and international standards (known as UTC).

For time synchronizing a clock, the GPS signal is received and distributed by a master clock, time server, or primary reference source to a device, system, or network so the local clocks are synchronized to UTC. Typical accuracies range from better than 500 nanoseconds to 1 millisecond anywhere on earth. The GPS clock synchronization eliminates the need for manual clock setting (an error-prone process). The benefits are numerous and include: legally validated time stamps, regulatory compliance, secure networking, and operational efficiency.

A freeware called GPS Time and Test is a PC clock synchronization program. It uses NMEA protocol. $GPZDA, $ZQZDA or $GPRMC protocol sentences are explored as time source.

Legal Terms and Regulations

In general, GPS is a free service for the ordinary consumers. There is no legal issue here. However if a system is made up of map data, there is some legal issues involves copyright and regulations. The major concerns are the source and abuse of the map data, copyright, country border argument, accuracy, and military facilities. Here I listed some challenges that a system designer may meet.

1. Google only allows users to access its map data and map tiles via AJAX API or Android API. Although the map tiles' addresses are quite simple to access, it is forbidden. Google also use some cookies to track the satellite map tiles. The famous 3rd party MGmap has to give up caching the Google's map tiles because of this issue. Now MGmap has to use different maps from Yahoo and Live.
2. Google forbids any commercial application with its free map API. The Google map based services have to be open and free. The commercial applications have to purchase the commercial services.
3. Google forbids any application for any vehicle navigation with its API.
4. Live virtual earth forbids any applications for real-time tracking with its API.
5. In some countries like China, all the web map services have to shift on purpose for security reasons. That means the GPS coordinate is not as identical as the Chinese map coordinate.
6. In China, online custom map is not allowed. Although this is not a law or a regulation, many map suppliers including Google has disable such service. But it is legal and encouraged in other countries.
7. More explicit and implicit rules...