O'Mara, 3rd hour
December 21, 1987
Imagine.... you are going to a house in a neighborhood that you don't know very well. You've been given only an address, with no directions. However, you are not worried. You turn to a small computer screen on your dashboard and push a few buttons. Within moments, a map is shown with your car and your destination indicated. Following the labeled streets shown on the screen, you reach the house with time to spare.... Does this sound like something out of a James Bond movie? Perhaps, but with the advanced technology of today, this fantasy has been made reality. All of the major car companies and many private companies as well are experimenting with different forms of computer maps and navigation systems to be used inside the car. Although there are many different methods by which to achieve this, the two most popular concepts being currently developed are satellite positioning and map matching.
The principle company using satellite positioning is called Navstar Global Positioning System (GPS). GPS will consist of 18 satellites orbiting the earth at an altitude of 10,898 miles above sea level. This will create a twelve-hour orbiting period, enabling the satellite to be updated daily with weather, traffic conditions, etc. Any and all cars equipped with a GPS receiver will be able to receive this information as well as determine their location. To do this, the receiver will pick up signals from four satellites and, by means of geometric triangulation, calculate the vehicle's latitude, longitude, and altitude. The vehicle's location will then be displayed on a color cathode ray tube (CRT). As the vehicle moves along the streets, it will move along the map on the CRT screen, leaving a trail of blue. This can assist the driver in planning his next moves.
Navstar GPS also includes an option that will permit drivers to plan their trips in advance. They will be able to program origin, destination, and intermediate stopping points into the computer, then retrieve this information at the touch of a button. The relative bearing and distance to each stopping point will be displayed throughout the trip. This would insure against getting lost in unfamiliar territory.
Unfortunately, Navstar's GPS is not yet available to the public, as a few of its 18 satellites have not yet been launched. Although it was expected to be completed by this time , the loss of the Challenger delayed the final launchings. However, when the project is completed, it is expected to achieve great success.
Automobile computer navigation is also being directed toward map matching. The principle system using this technique is Etak "Navigator", which is already available for public use in some parts of the US. The Navigator makes use of the fact that automobile navigation, unlike sea or air navigation, is confined to a finite network of streets and roads. This way, a computer can calculate a vehicle's course through dead reckoning and then compare this course to a map data base. Dead reckoning is the process of determining a vehicle's location and heading relative to an initial position by integrating measured increments and direction of travel. Then, if a turn is executed that approximates a mapped turn, the vehicle is presumed to be at the mapped location, and is pictured there. This process eliminates any dead reckoning error that may have accumulated since the last turn.
Etak uses a 4.5 inch CRT display mounted on the dashboard. On it, the car is shown as a stationary arrowhead against a moving background. The background map can be zoomed as close in or as far out as desired. In the closest mode, the map shows a .25 square mile, with every street pictured and labeled. in the furthest mode, only the interstate system is shown.
Also included in the Etak system is a destination-finder. By pushing a few buttons along the side of the screen, one can easily select an intersection, street, or specific address. Within seconds, the Navigator will locate the destination, and display it as a blinking star on the screen. it will also include how many miles and in what idrection the destination is from the car's current location.
Both the GPS and the Navigator each have some good aspects, but also some problems. For instance, GPS satellite signal reception may be impaired due to tunnels, buildings, mountains, etc. At such times it might be best to use Etak's system of map matching. However, on long straightaways, with no turns to let the Navigator correct itself, it could become lost. Also, if a car is towed or moved somewhere while the computer is not on, it would be lost. In cases such as these, the GPS would probably do a better job. Therefore, it seems that the best solution would be one system that combined the best qualities of each.
Such a system would be very useful in today's travel-oriented world Not only could the private user find new locations with the computer map, but many companies could profit. A rental car company could install them in their cars for customers new to the area. A trucking company could use them so drivers would be able to ship to unfamiliar cities. Any company that provides delivery could use it to widen its range. A taxi-cab service definitely could use such a mapping system. The possibilities are endless. This system would permit a person to travel with ease through any territory, no matter how complex - even if he's never seen it before.
It is obvious, in reviewing just a few of the many possibilities this computer mapping system could hold, that the social aspects show great promise. However, there are some potential difficulties. For instance, if a driver spends too much time concentrating on the map display, he could get into an accident, especially if he tries to program a destination while driving. Etak has made some attempts to relieve this problem by fixing its product so that a destination cannot be programmed while the car is in motion, but the problem still exists. Another problem is that neither program includes such information as one-way streets.
Despite some bugs that must be worked out, both systems show excellent possibilities. If the two were combined, there is no telling what wonders could evolve. The computer maps will free society from the constraints of their own meager knowledge, from the hassle of confusing maps, and from the embarrassment of asking directions. Equipped with a computer map such as the one described, society will now truly be able to boldly go where they have never gone before.
[transcribed by hand; references eliminated for brevity] Grade: A- (93%)