What is the relationship between standard deviation in cm/s of measured cells, measuring time and cell size?

FAQ - OTT Qliner - Acoustic Doppler Current Profiler

1. How do I fix the rope to the boat while measuring from a bridge?
2. How can I reduce the drift of the boat at high velocities?
3. What is the recommended cell size?
4. What is the minimum depth required for measuring discharge with an OTT Qliner?
5. How the discharge is computed by OTT Qliner?
6. What is the minimum battery voltage of the Qliner?
7. Can I change cell size during a discharge measurement?
8. What is the purpose of beam 3?
9. What is the recommended measuring time?
10. What is the recommended number of cells?
11. What is the average battery life of the Qliner?
12. Does the OTT Qliner operate using the “bottom tracking” functionality?
13. How many times can the battery be charged before it requires replacement?
14. What is the typical life of the 9 volt battery in the Bluetooth adapter?
15. The computed discharge on the PDA differs from the result in Qreview. What is the reason?
16. What could be happen if I have problems with Bluetooth data transmission?
17. What is the maximum river width for OTT Qliner measurements?
18. Does the OTT Qliner give information about the velocity at different depths? Or only an average value for each vertical?
19. Do I need to keep the boat normal to the cross section?
20. My PDA is equipped with Bluetooth. Can I use it for OTT Qliner operation?
21. What is the ping rate of the OTT Qliner?
22. Q: What is the relationship between standard deviation in cm/s of measured cells, measuring time and cell size? A: See table below.

    Cell Size (ft)	Measuring Time (s)
    	30	40	60	100
    0.3	0.19	0.16	0.13	0.10
    0.7	0.10	0.09	0.07	0.05
    1.0	0.06	0.05	0.04	0.03
    1.6	0.04	0.03	0.003	0.002