Navigation computers, now sold by most car-makers, cost $2,000 and up. No surprise, then, that they aremost often found in luxury cars, like Lexus,BMWand Audi. But it is a developing technology-meaningprices should eventually drop-and the market doesseem to be growing.
Even at current prices, a navigation computer is impressive. It can guide you from point topoint in most major cities with precise turn-by-turn directions-spoken by a clear human-sounding voice. and written on ascreen in front of the driver.
The computer works with an antenna (天线) that takes signals from no fewer than three or the24, global positioning system (GPS) satellites. By measuring the time required for a signal totravel between the satellites and the antenna. the car's location can be pinned down within l00 meters.
The satellite signals. along with inputs on speed from a wheel-speed sensor and direction froma meter, determine the car’s position even as it moves. This information is combined with amap database. Streets, landmarks and points of interest are included.
Most systems are basically identical. The differences come in hardware-the way the computeraccepts the driver's request for directions and the way it presents the driving instructions. Onmost systems, a driver enters a desired address, motorway junction or point of interest via atouch screen or disc. But the Lexusscreen goes a step further: you can point to any spot onthe map screen and get directions to it.
BMW's system offers a set of cross hairs(瞄准器上的的十字纹)that can be moved across themap (you have several choices of map scale) to pick a point you'd like to get to. Audi's screencan be switched to TV reception.
Even the voices that recite the directions can differ, with better systems like BMW's andLexus's having awider vocabulary. The instructions are available in French. German, Spanish, Dutch and Italian, as well asEnglish. The driver can also choose parameters for determining theroute: fastest, shortest or no freeways(高速公路), for example.
1. We learn from the passage. that navigationcomputers______________.
A) will greatly promote sales of automobiles
B) may help solve potential traffic problems
C) are likely to be accepted by more drivers
D) will soon be viewed as a symbol of luxury
2. With a navigation computer, a driver will easily find the best route to hisdestination________.
A) by inputting the exact address
B) by indicating the location of bis car
C) by checking his computer database
D) by giving vocal orders to the computer
3. Despite their varied designs, navigation computers used incars___________________.
A) are more or leas the same price
B) provide directions in much the same way
C) work on more or less the same principles
D) receive instructions from the same satellites
4. The navigation computer functions__________________.
A) by means of a direction finder and a speed detector
B) basically on satellite signals and a map database
C) mainly through the reception of turn-by-tum directions
D) by using a screen to display satellite signals
5. The navigation systems in cars like Lexus. BMW and Audi are mentioned toshow__________.
A) the immaturity of the new technology
B) the superiority of the global positioning system
C) the cause of price fluctuations in car equipment
D) the different ways of providing guidance to the driver
价格 : ￥780元
价格 : ￥780元