| 1. | Terrestrial positioning methods include traditional land-based techniques such as |
| | Sextant resection |
| | Triangulation |
| | Tag lines |
| | Microwave electronic distance measurement (EDM) systems |
| | Electronic total stations |
| | All of the above |
| | None of the above |
| 2. | Sextant positioning is not used to calibrate medium frequency hyperbolic, range-range, and microwave positioning systems. |
| | True |
| | False |
| 3. | Inexpensive hand-held GPS (Standard Positioning Service–SPS) receivers typically provide accuracies that equal or exceed sextant positioning. |
| | True |
| | False |
| 4. | The US Coast Guard used the __________________ technique on buoy tenders. |
| | Hopper dredge positioning |
| | 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. |
| | True |
| | False |
| 6. | In equation 7-1, σ = (δA + δB) / 2, What does δA represent? |
| | δA = d A-P . sin (δ a “ ) |
| | 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. |
| | True |
| | False |
| 8. | Visual range-pair alignment accuracy is a function of the _______________ from the targets and the range pair spread. |
| | Distance |
| | Displacement |
| 9. | The most ___________________tag line distance measurements are conducted while the survey boat is stationary and holding constant tag line tension and alignment. |
| | Accurate |
| | 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. |
| | Weakest |
| | Strongest |
| 11. | Wire rope tag line lengths vary from__________________ and baseline boat tag lines from ____________________ long. |
| | 100 ft to over 1,000 ft, 1,000 ft to 10,000 ft |
| | 500 ft to over 5,000 ft, 5,000 ft to 15,000 ft |
| | 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. |
| | True |
| | 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. |
| | Corrosion-resistant |
| | Corrosion-irresistant |
| 14. | Clutching and braking assemblies in the power winches __________________tag line payout. |
| | Regulate |
| | Do not regulate |
| 15. | Tag line surveys are highly accurate only within finite limits. |
| | True |
| | False |
| 16. | Flagged tag line intervals must be periodically calibrated every __________________against a chained or EDM distance. |
| | 1 to 3 months |
| | 3 to 6 months |
| | 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 ______________________. |
| | Estimated standard error of azimuth measuring system |
| | Estimated standard error of the distance measuring system |
| 18. | EDM is an acronym for ________________________. |
| | Electronic distance measurement |
| | Electronic displacement measurement |
| 19. | Land-based (or terrestrial) positioning systems are not distinguished from satellite positioning systems. |
| | True |
| | False |
| 20. | The method of classifying electronic positioning systems is by their operating ________________. |
| | Frequencies |
| | Pulse |
| | Voltage |
| 21. | LORAN-C is a _______________________ time-differencing hyperbolic system. |
| | Low frequency |
| | 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. |
| | True |
| | False |
| 23. | Signal multipath reflection is not a major systematic error component for equipment operating in the microwave band. |
| | True |
| | 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 __________________. |
| | Sum of the observed ranges |
| | 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. |
| | EDM |
| | Baseline |
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