1. What is the role of digital technologies in mapping process?
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____ _________ 2008.
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: 6.070900
6.070900 㳿
Variant 8
I. Translate the following text in writing and put 5 questions to the underlined sentence.
If the signal is weak, it is possible to track more than 1 ms of data to improve sensitivity. It seems that the maximum data length that can be tracked coherently is 20 ms without very sophisticated processing because the navigation data is 20 ms long. The input data must be properly selected and there should not be a phase transition within the selected 20 ms of data. Under this condition, the sensitivity is improved by 13 dB (10 log (20 /1)) over tracking 1 ms of data. If the data length is longer than 20 ms, it may contain a phase transition due to the navigation data. The phase transition will disturb the operation of the tracking program. If multiples of 20 ms of data are used, the tracking process must cover all the possible combinations of phase transition.
The data length contains a phase transition due to the navigation data.
II. Give the English equivalents to the following terms.
1. possible combinations 9. to cover
2. tracking program 10. to disturb
3. navigation data 11. to contain
4. phase transition 12. to be improved
5. input data 13. to track
6. sophisticated processing 14. to process
7. weak signal 15. to select
8. sensivity 16. to improve
III. Translate sentences into English.
1. - ArcCadastre. 2. . 3. ϳ . 4. . 5. . 6. , ArcCadastre. 7. , .
I V. Give extended answer to the following question.
1. What opportunities will the 24th International Cartograpic Conference bring?
3
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______ ..
____ _________ 2008.
: () ( )
: 6.070900
6.070900 㳿
Variant 9
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I. Translate the following text in writing and put 5 questions to the underlined sentence.
The next step is to change the output data (every 20 ms) into +1 and −1 (or 0) values. There are several ways to accomplish this. One common way is to find the difference between adjacent millisecond outputs. If the difference is beyond a certain threshold, there is a data transition. For the conventional tracking program, the threshold is usually obtained from the minimum amplitude of the output. Since strong and weak signals produce different amplitudes, the minimum values should be used as the threshold. For the BASS method the threshold is at p /2. From these transitions, it is easy to change the tracking results into navigation data. The navigation data transition points must correspond to individual points in the collected input data, which have a time resolution of 200 ns. This time resolution can be used to find the relative time difference between different satellites.
The time resolution can be used to find the relative time difference between different satellites.
II. Give the English equivalents to the following terms.
1. time resolution 9. threshold
2. collected input data 10. tracking program
3. navigation data 11. to correspond to
4. tracking results 12. to accomplish
5. minimum values 13. to be obtained from
6. different amplitudes 14. to find the difference
7. weak signals 15. be used as
8. data transition 16. to change the output data
III. Translate sentences into English.
1. - ArcGIS. 2. . 3. ϳ . 4. . 5. . 6. , ArcGIS. 7. ArcGIS .
