System Configuration
108
windows permit larger incremental changes. Pressing
Custom Value
allows you to enter an
exact value, which can also exceed the value obtained by just pressing the
+
button. For
example, using a 100 MHz antenna, pressing the + button repeatedly will get a maximum time
window of 4000 ns. However, by pressing Custom Value, it is possible to set a maximum time
window up to 24,000 ns.
The maximum time window varies with antenna frequency and is shown in the table below. It is
calculated based on the fact that the system can collect a maximum of 30,000 points/trace, and
follows the equation:
Time window = 30,000 / Sampling Interval
The scan depth is also displayed below the time window as many users are more comfortable
relating to depth. The calculated scan depth uses the velocity set in the system configuration
settings, based on the (approximate) equation:
Depth = Velocity x Time / 2
The following table shows the default (and maximum) time window for each frequency, as well
as the approximate scan depth, assuming a material propagation velocity of 0.1 m/ns (0.328
ft/ns).
Frequency
(MHz)
Default Time
Window (ns)
Maximum
Time Window
(ns)
Approximate
Depth (m)
Approximate
Depth (ft)
12.5
1600
192,000
80
262
25
800
96,000
40
131
50
400
48,000
20
66
100
200
24,000
10
33
200
100
12,000
5
16
250
100
12,000
5
16
500
50
6000
2.5
8
1000
25
3000
1.25
4
6.1.3
Step Size
Reflection Surveys
Antenna Step Size is the distance antennas are moved to collect a new trace during a survey.
Select the correct Antenna Step Size to resolve subsurface targets:
•
A step size that is too coarse may result in missed subsurface targets.
Summary of Contents for pulseEKKO
Page 1: ...2005 00040 09 ...
Page 2: ...ii ...
Page 4: ...Warranty Confirmation iv ...
Page 10: ...x ...
Page 14: ...Introduction 2 ...
Page 72: ...Assembling Full Configurations 60 ...
Page 80: ...Getting Started 68 ...
Page 116: ...Tools and Preferences 104 ...
Page 180: ...Collecting Data 168 ...
Page 190: ...Map View 178 ...
Page 198: ...Managing Data 186 ...
Page 221: ...Care Maintenance 209 ...
Page 222: ...Care Maintenance 210 ...
Page 226: ...Technical Specifications 214 ...
Page 228: ...Appendix A 216 ...
Page 234: ...Appendix B 222 ...
Page 236: ...Appendix C 224 ...
Page 238: ...Appendix D 226 ...
Page 246: ...Appendix E 234 ...
Page 248: ...Appendix F 236 ...
Page 250: ...Appendix G 238 ...