FILTER GP-OIL 2316182 - Caterpillar

GPS Position Error
The accuracy of a GPS position varies according to many different conditions. An RTK position is normally accurate enough for construction work. However, this is not always the case.When a GPS antenna is placed in a stationary position and the position output is monitored, there are small changes in the position. The position change is caused by noise in the solution. This results in a small error in the GPS position.The GPS error is an estimate of the amount of noise in the GPS positions.The Role of the GPS Receiver
The satellites are above the antenna so the horizontal and vertical accuracies are different. The vertical position is less accurate than the horizontal position. You can display vertical position error and horizontal position error as text items. Refer to "GPS Accuracy Mode Text Items" for more information.Blade guidance will only occur when the GPS accuracy for the antenna position is within the GPS error limit set for the GPS Accuracy Mode.GPS Accuracy Mode Text Items
Three text items that are related to GPS accuracy mode are available for display.
The "H. GPS Err." text item shows the GPS error in the horizontal plane.
The "V. GPS Err." text item shows the GPS error in the vertical plane.
The "GPS Acc. Mode" text item shows the currently selected GPS Accuracy Mode.The "H. GPS Err." text item and the "V.GPS Err." text item change color in order to indicate the current GPS error relative to the configured GPS Error Limit. The color coding that is used is shown in table 1.
Table 1
Text Color     GPS Error Indication    
Black     The GPS error is within 90% of the GPS error limit.    
Blue     The GPS error is within 10% of exceeding the GPS error limit.    
Red     The GPS error has exceeded the GPS error limit.    Setting the GPS Accuracy Mode and Limits
The operator can select a GPS Accuracy Mode. You can change the Accuracy mode in Normal mode, but you must be in Service mode in order to change the GPS Error Limits.Perform the following steps in order to access the "GPS Accuracy Mode" dialog.
Turn the AccuGrade System on.For AccuGrade Systems running Version 5.5 firmware, proceed to Step 2.For AccuGrade Systems running Version 6.1, proceed to Step 5.
From the "Setup Menu - Configuration" dialog, press the down arrow key or the up arrow key until the "GPS Accuracy Mode" is highlighted.
Press the "OK" key. The dialog in Illustration 1 appears.
Illustration 1 g01255366
Press the down arrow key or the up arrow key in order to select the mode for operation.Proceed to Step 7.
From any guidance screen, press the "GPS" Soft Key.
Illustration 2 g01255591
Press the Change Mode Soft Key (6) in order to swap between the following modes: Fine Accuracy, Medium Accuracy and Course Accuracy.
Press "OK" in order to confirm the settings, or "ESC" in order to exit without saving.Note: If you press "ESC", you are asked to confirm that you do not want to save any changes.Editing The GPS Accuracy Modes
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