Collected survey data is blue and red only.

Symptoms:

Normally collected survey data is colored with a spectrum of red (low) through green through blue (high). In this instance there appears to only be two colors: red and blue.

Causes:

T3RRA software fits a red-green-blue spectrum of color to the survey points. It “stretches” these colors across the range of data points. If the data is “clumped” in groups that are well apart numerically then the majority of the spectrum of color will not be seen.

1. One or more points has received a corrupted elevation value, placing it well above or below the bulk of the points
2. The base station has changed it’s elevation part way through the survey. Points collected before will be offset by this change.

Solutions:

1. If there are only a few corrupted data points, simply delete them using the tools available in surveying or surfacing.
2. If this problem is caught while surveying, stop the survey immediately. Check to see if the base station has been altered and fix it. Then delete the points that were too high or low and begin surveying at the location where the problem began.
3. If it is not possible to resurvey the affected part of the field you have several (bad) options
   1. Export the elevation points as a CSV file. Open the CSV points in a spreadsheet. Add the appropriate offset to all bad points. Save the file as a CSV. Import this CSV file in the T3RRA software.
      OR 
   2. Surface the collected data. Create a region around the section of the field that is too high or too low. Use the ‘Offset Surface’ design tool to change the height of the problem region. Some smoothing across regions may also be required. From this point onwards, use the resultant design surface as the basis for further designs.