| 1. |
Terrestrial positioning methods include traditional land-based techniques such as |
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Sextant resection |
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Triangulation |
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Tag lines |
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Microwave electronic distance measurement (EDM) systems |
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Electronic total stations |
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All of the above |
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None of the above |
| 2. |
Sextant positioning is not used to calibrate medium frequency hyperbolic, range-range, and microwave positioning systems. |
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True |
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False |
| 3. |
Inexpensive hand-held GPS (Standard Positioning Service–SPS) receivers typically provide accuracies that equal or exceed sextant positioning. |
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True |
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False |
| 4. |
The US Coast Guard used the __________________ technique on buoy tenders. |
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Hopper dredge positioning |
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Redundant sextant re-sectioning |
| 5. |
Plotting sextant fixes with a three-arm protractor aboard a moving vessel is not an exact process, and significant inaccuracies can result. |
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True |
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False |
| 6. |
In equation 7-1, σ = (δA + δB) / 2, What does δA represent? |
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δA = d A-P . sin (δ a “ ) |
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δA= d B-P . sin (δ a “ ) |
| 7. |
Multiple azimuth intersection techniques provide redundancy and allows for an on-line assessment of the accuracy of the resultant position. |
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True |
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False |
| 8. |
Visual range-pair alignment accuracy is a function of the _______________ from the targets and the range pair spread. |
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Distance |
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Displacement |
| 9. |
The most ___________________tag line distance measurements are conducted while the survey boat is stationary and holding constant tag line tension and alignment. |
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Accurate |
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Inaccurate |
| 10. |
Lateral alignment control of the survey boat can be the __________________ link in the performance of tag line surveys, especially if strong currents are present. |
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Weakest |
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Strongest |
| 11. |
Wire rope tag line lengths vary from__________________ and baseline boat tag lines from ____________________ long. |
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100 ft to over 1,000 ft, 1,000 ft to 10,000 ft |
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500 ft to over 5,000 ft, 5,000 ft to 15,000 ft |
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1000 ft to over 5,000 ft, 5,000 ft to 15,000 ft |
| 12. |
The tag line cable is marked at any desired interval, usually every 25 ft. |
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True |
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False |
| 13. |
______________swivels are inserted along the tag line at intermediate points, usually at the 100-ft mark, the 500-ft mark, and at subsequent 500-ft intervals thereafter. |
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Corrosion-resistant |
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Corrosion-irresistant |
| 14. |
Clutching and braking assemblies in the power winches __________________tag line payout. |
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Regulate |
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Do not regulate |
| 15. |
Tag line surveys are highly accurate only within finite limits. |
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True |
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False |
| 16. |
Flagged tag line intervals must be periodically calibrated every __________________against a chained or EDM distance. |
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1 to 3 months |
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3 to 6 months |
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6 to 9 months |
| 17. |
The accuracy of a range-azimuth position can be estimated from the following equation: RMS 95% = 1.73 • sqrt [ a 2 + ( d • tan b) 2 ] where ‘a’ is ______________________. |
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Estimated standard error of azimuth measuring system |
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Estimated standard error of the distance measuring system |
| 18. |
EDM is an acronym for ________________________. |
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Electronic distance measurement |
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Electronic displacement measurement |
| 19. |
Land-based (or terrestrial) positioning systems are not distinguished from satellite positioning systems. |
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True |
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False |
| 20. |
The method of classifying electronic positioning systems is by their operating ________________. |
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Frequencies |
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Pulse |
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Voltage |
| 21. |
LORAN-C is a _______________________ time-differencing hyperbolic system. |
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Low frequency |
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High frequency |
| 22. |
Variations in the velocity of propagation in air are caused by changes in air density due to temperature, humidity, and air pressure. |
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True |
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False |
| 23. |
Signal multipath reflection is not a major systematic error component for equipment operating in the microwave band. |
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True |
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False |
| 24. |
In equation 7-7, an approximate estimate of the range accuracy is obtained as :
Estimated Range Accuracy (1- σ ) = sqrt [ Σ ( v2 ) / (n-1) ], where Σ ( v2) is __________________. |
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Sum of the observed ranges |
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Sum of the squared residuals |
| 25. |
_______________ Calibrations are performed by locating the survey vessel alongside a known reference point and comparing the computed (inversed) distances with the ranges observed by the microwave system. |
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EDM |
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Baseline |
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