Focus On Water Division
Nebraska Department of Environmental Quality
Standard Operating Procedure

Water Quality Division
Water Quality Assessment Section - GW

Standard Operating Procedure Number GW-090
Title: Collecting Data Using the Trimble GeoExplorer GPS Unit
Written Date: September 1, 2000
Approved Date:


Purpose: To collect latitude and longitude data at a well using a GPS Unit.

Equipment/Materials Needed:
  1. Trimble GeoExplorer Unit
  2. Camera Tripod with bracket to hold GeoExplorer
  3. Power Source - Batteries
    1. Rechargeable Camcorder Type with cable/cord
    2. 4 AA
  4. Laptop computer with Pathfinder Office software
    1. Power supply cord/transformer that operates laptop and recharges internal battery
  5. GeoExplorer Cables
    1. GeoExplorer to Laptop
    2. GeoExplorer to Rechargeable Battery
  6. Battery Recharger

Procedures:
1. Place GeoExplorer on tripod (make sure the GeoExplorer is connected to the battery).
2. Place tripod so the antenna can get a clear 360 degree view.
3. Turn on GeoExplorer.
4. Check status of Options selected for the sampling by the Project Manager. Select “6. Configuration” from Main Menu.
4.1. The following table lists the different Rover Options and the value to use.
Points 1s
Lines/Areas 5s
Min Posn 120
Not In Feature
Rate All
High Accuracy
High Off
(Skip to Dynamics)
Dynamics Land
Pos Mode 3D
(Skip to Elev Mask)
Elev Mask 15
SNR Mask 5
PDOP Mask 6
PDOP Switch 6
Antenna Ht. 3.28 feet
Log DOPs off
Velocity off
File Prefix This is set by the Project Manager.
4.2. Base Options are not used.
4.3. The Coordinates are set to Deg/Min/Sec.
4.4. Datum Is WGS-84.
4.5. The Units should be set to English.
4.6. Date and Time
Date Format is MM/DD/YY
Check Local Time for accuracy
Time Display is Local 24 Hours
4.7. Skip Communications and RTCM
4.8. Sat Helath is set to Ignore Health.
4.9. Battery Usage should be reset after each battery recharge event.
4.10. WPT Averaging is Off.
4.11. Ignore Fact. Defaults and About GeoExpl.
4.12. Escape back to Main Menu.
5. Select “3. GPS Status” from Main Menu.
6. Select “1. Sat Tracking” to make sure 4 satellites are being tracked and the PDOP < 7.
7. Escape back to Main Menu.
8. Select “1. Data Capture” from the Main Menu.
9. Record start time on field data sheet.
10. Select “1. Open Rov. File”. The GeoExplorer has begun recording data.
11. Record file name (e.g. R070913A) on field data sheet.
11.1. The file prefix letter can be set to any letter. This can be set up in the Configuration/Rover Options/File Prefix Menu. It is R in this example.
11.2. The remainder of the file name is the date and GMT hour, and the file in this hour. In the example, 0709 is July 9th. 13 is 1300 PM GMT. “A“ means this is the first file recorded in this hour.
12. Record offset distance on field data sheet.
13. After 5 minutes (10 minutes maximum), select “Close File”. Answer Yes when prompted to close file.
14. Record end time on field data sheet.
15. Escape out to Main Menu.
16. Turn off GeoExplorer.