求翻译：GPS全球卫星定位系统的公交语音报站系统：1973年，美国开始研制全球定位系统GPS，经过20年的不断完善，耗资200亿美元后，该系统终于在1994年全面建成，并逐渐用于各个领域[8]。公交车报站系统通过GPS对公交车进行全球定位，若到达某一站台则进行相应站名的语音播报[9]。这种报站系统已经在美国的一些城市投入使用，但投资昂贵，在一些中小城市难以承受是什么意思？

null

Gps global positioning system bus station system voicemail: in 1973, the United States began developing the Global Positioning System (GPS, after 20 years of the continuous improvement of $2 billion dollars, the system was finally in 1994, as well as gradually fully completed for all fields [8]. Bus

GPS全球卫星定位系统的公交语音报站系统：1973年，美国开始研制全球定位系统GPS，经过20年的不断完善，耗资200亿美元后，该系统终于在1994年全面建成，并逐渐用于各个领域(8)。公交车报站系统通过GPS对公交车进行全球定位，若到达某一站台则进行相应站名的语音播报(9)。This kind of newspaper station system already in US's some city operational, but invests expensively, withstands with difficulty in some small and medium-sized t

Bus voice-announce system GPS global positioning system: in 1973, the United States began developing a global positioning system GPS, and after 20 years of continuous improvement, at a cost of 20 billion dollars before the system was fully built in 1994, and used in various fields [8]. Bus stop-repo

null