Geophysical Survey Systems 4108F GPR with 4108F Antenna User Manual QF74108F Manual

Geophysical Survey Systems, Inc. GPR with 4108F Antenna QF74108F Manual

Manual

Model 4108F Horn Antenna System Settings and User Notes We Provide Complete Survey Solutions 13 Klein Drive, P.O. Box 97 North Salem, NH 03073-0097 Phone: (603) 893-1109 / Fax: (603) 889-3984 www.Geophysical.com Sales@Geophysical.com February 2002Geophysical Survey Systems, Inc.
Geophysical Survey Systems, Inc. Model 4108F Antenna System Settings and User’s Notes MN34-560 Rev -
Geophysical Survey Systems, Inc. Model 4108F Antenna System Settings and User’s Notes MN34-560 Rev - LIMITED WARRANTY, LIMITATIONS OF LIABILITY AND RESTRICTIONS Geophysical Survey Systems, Inc. hereinafter referred to as GSSI, warrants that, for a period of 12 months from the delivery date to the original purchaser, GSSI's products will be free from defects in materials and workmanship. EXCEPT FOR THE FOREGOING LIMITED WARRANTY, GSSI DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. GSSI's obligation is limited to repairing or replacing parts or equipment which are returned to GSSI, transportation and insurance pre-paid, without alteration or further damage, and which in GSSI's judgment, were defective or became defective during normal use. GSSI ASSUMES NO LIABILITY FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR INJURIES CAUSED BY PROPER OR IMPROPER OPERATION OF ITS EQUIPMENT OR SOFTWARE, WHETHER OR NOT DEFECTIVE. Before returning any equipment to GSSI, a Return Material Authorization (RMA) number must be obtained. Please call the GSSI Customer Service Manager who will assign an RMA number. Be sure to have the serial number of the unit available. GSSI does not convey any license under its patent or other intellectual property rights or the rights of others. NOTE: Information in this manual is subject to change without notice. Please consult the manual updates supplied with your system and contact GSSI with any additional questions. Copyright  2002 Geophysical Survey Systems, Inc. All rights reserved including the right of reproduction in whole or in part in any form. Published by Geophysical Survey Systems, Inc. 13 Klein Drive North Salem, New Hampshire 03073-0097 Printed in the United States GSSI and SIR are registered trademarks of Geophysical Survey Systems, Inc. Windows is a registered trademark of the Microsoft Corporation.
Geophysical Survey Systems, Inc. Model 4108F Antenna System Settings and User’s Notes MN34-560 Rev - FCC NOTICES: This device complies with part 15 of the FCC Rules: Operation is subject to the following conditions: 1. This device many not cause harmful interference, and 2. This device must accept any interference received, Including interference that may cause undesired operation Warning: Changes or modifications to this unit not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment. Operation of this device is restricted to law enforcement, fire and rescue officials, scientific research institutes, commercial mining companies, and construction companies. Operation by any other party is a violation of 47 U.S.C. § 301 and could subject the operator to serious legal penalties. Coordination Requirements. (a) UWB imaging systems require coordination through the FCC before the equipment may be used. The operator shall comply with any constraints on equipment usage resulting from this coordination. (b) The users of UWB imaging devices shall supply detailed operational areas to the FCC Office of Engineering and Technology who shall coordinate this information with the Federal Government through the National Telecommunications and Information Administration. The information provided by the UWB operator shall include the name, address and other pertinent contact information of the user, the desired geographical area of operation, and the FCC ID number and other nomenclature of the UWB device. This material shall be submitted to the following address: Frequency Coordination Branch., OET Federal Communications Commission 445 12th Street, SW Washington, D.C. 20554 ATTN: UWB Coordination (d) Users of authorized, coordinated UWB systems may transfer them to other qualified users and to different locations upon coordination of change of ownership or location to the FCC and coordination with existing authorized operations. (e) The NTIA/FCC coordination report shall include any needed constraints that apply to day-to-day operations. Such constraints could specify prohibited areas of operations or areas located near authorized radio stations for which additional coordination is required before operation of the UWB equipment. If additional local coordination is required, a local coordination contact will be provided. (f) The coordination of routine UWB operations shall not take longer than 15 business days from the receipt of the coordination request by NTIA. Special temporary operations may be handled with an expedited turn-around time when circumstances warrant. The operation of UWB systems in emergency situations involving the safety of life or property may occur without coordination provided a notification procedure, similar to that contained in CFR47 Section 2.405(a)-(e), is followed by the UWB equipment user.
Geophysical Survey Systems, Inc. Model 4108F Antenna System Settings and User’s Notes MN34-550 Rev A 1 Antenna Mounting Assembly
Geophysical Survey Systems, Inc. Model 4108F Antenna System Settings and User’s Notes MN34-550 Rev A 2 Mounting and Data Collection Recommendations Mounting Specifications: The Model 4108F antenna mounting hardware includes 2 square fiberglass tubes and 2 gusset plates. Figure 1 shows a typical 4108 setup on the back of GSSI’s van. Figure 1: Typical Model 4108F setup showing fiberglass rods and gusset plates. The vertical metal pieces attached to the gusset plates are sold separately. It is recommended that the user follow the following specifications for mounting the 4108F antennas: (1) Recommended antenna bottom height above pavement with vehicle stationary: 18-20” (46 – 51 cm) (2) Recommended closest distance between antenna and significant metal (vertical metal rods or the vehicle’s bumper) should be at least 40” (1 m). (3) Black transducer cable should be fastened to one of fiberglass rails to prevent cable movement. (4) Excessive antenna bouncing should be minimized. The GSSI van setup includes 4 adjustable straps that minimize vertical and horizontal antenna movement, especially on bumpy roads. 18-20” (46-51 cm) 40” (1 meter) Transducer cable fastened to rail Adjustable straps
Geophysical Survey Systems, Inc. Model 4108F Antenna System Settings and User’s Notes MN34-550 Rev A 3 Data Collection Recommendations: The following software settings are recommended for general Model 4108F data collection. See the SIR-20 manual for instructions on how to make setting modifications. Table 1. Recommended data collection settings for Model 4108 antenna. SIR-20 Transmit Rate 100 KHz Samples/Scan 512 Scans/Sec: 160 Time Range 20 ns Bits/Sample 16 Vertical Filter Settings: IIR High Pass 1 MHz FIR High Pass 250 MHz FIR Low Pass 3000 MHz Position: Signal position should be adjusted so that the latest arriving wavelet of the direct-coupling is near the top of the scan. This wavelet should always be visible in the data. GSSI’s post-processing software requires the presence of this wavelet in the data. Figure 2 shows a typical scan of data with the signal properly positioned. Figure 2: Typical data scan obtained with Model 4108F and recommended software settings. Direct-coupling waveform Pavement surface reflection
Geophysical Survey Systems, Inc. Model 4108F Antenna System Settings and User’s Notes MN34-550 Rev A 4 Gain: Data collection gain for the 4108F antenna should be adjusted so that the peak amplitude of the pavement surface reflection is approximately 2/3 of the total screen width. For example, in Figure 2 the pavement surface reflection has an amplitude of approximately 20000 and the full screen width is 32000. Using the filter settings described in Table 1, a gain of 13-14 dB is typical for most pavement surfaces. However, for more highly reflective surfaces, such as concrete, the user may have to decrease the gain value. It is very important that the pavement surface reflection amplitude (and metal plate reflection when performing calibration) never reach its maximum. Figure 3 shows an improperly gained signal. Figure 3: Example of Model 4108F data scan collected with too much gain.
Geophysical Survey Systems, Inc. Model 4108F Antenna System Settings and User’s Notes MN34-550 Rev A 5 Quick Setup Procedure SIR-20 1. Connect the transducer cable from the SIR-20 (Channel 1) to the Model 4108F antenna. 2. Connect the power supply to the SIR-20. 3. Connect the Model 10F marker cable to the marker connector on the SIR-20, shown in Figure 4. The SIR-20 will not operate with a horn antenna without this cable attached. Figure 3. Location of attachment of Model 10F marker/transmit switch cable. 4. Turn on the SIR-20 and wait until it is booted-up. 5. Double-click on the SIR-20 Desktop shortcut. 6. Press to recall a saved project for the Model 4108F antenna. • First time users may want to select the “1GHz Horn Free Run” project from the folder “Fixed SIR-20 Setups.” 7. Press to run the project. Be sure to keep the red “trigger” pressed on the handle of the model 10F marker/transmit switch cable as shown in Figure 4. If the red trigger is released at any time during data collection, data collection will be paused after 2 seconds and the data file will be closed after 10 seconds. Attachment location of Model 10F marker/transmit switch
Geophysical Survey Systems, Inc. Model 4108F Antenna System Settings and User’s Notes MN34-550 Rev A 6 Figure 4. The red trigger on the Model 10F handle must be pressed at all times during project setup and data collection using a horn antenna. 8. The position of the signal may be shifted and the data collection settings may be slightly different than those currently recommended. Change the signal position if necessary so that it is similar to the signal position shown in Figure 1. • Compare all of the settings listed in Table 1 to those on the SIR-20 and make any necessary adjustments prior to collecting data. • Also check the gain of the signal to make sure it is not clipping. Save any changes made to the signal position and signal gain to a new macro prior to collecting data. The red transmit trigger on the Model 10F cable must be pressed at all times during project setup and data collection

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