How to Survey a Field for Landforming Design

Last Updated: 18 September 2018

When a survey is performed, it creates a survey file for the field that contains a collection of data points.  Each point represents a specific latitude and longitude or Easting and Northing position within the field for which an elevation value is stored.

The data collected can be valuable to create informational maps.  Any maps created from this data is only as good as the quality of the data that creates it. In order to create quality maps from your field survey data, be sure to perform your field survey to the highest quality.  As a start, please observe the following guidelines as a minimum for performing a field survey.

  1. Use a RTK GPS receiver with a local base station within 1.6km or 1 mile for the highest accuracy and quality survey data. Using an inappropriate differential correction for collecting elevation data leads to inaccurate maps which leads to increased earthworks and earthworks imbalances.

  2. Mark the Master Benchmark and record the horizontal and vertical position.  A concrete pad is typically used.  At the very least, mark the ends of the machine inline with the antenna using two pegs.

  3. Make the first pass on the exterior field boundary, when collecting survey data, to ensure sufficient data around the perimeter of the field for the design surface to extend to. OptiSurface Designer will extrapolate (extend) the design surface a little outside the defined survey boundary. This extrapolation distance could be 1m (3ft) in some places around the boundary and further in other places eg. 10m or 30ft, depending where the calculation grid falls.  

  4. Conduct a thorough survey by driving up and down the field on approximately the following swath spacing:

    • Fields with significant elevation changes and slopes — swath spacing of 7.5—15 m (25—50 ft.) is recommended.
    • Flatter fields — a swath spacing of 15 m (50 ft.) is recommended.
    • Flat to precision leveled ground — a swath spacing of 15—30 m (50—100 ft.)  Do not exceed 50 m (100 ft.) swath spacing for surveying purposes.

  5. The recording distance between the survey points as you drive along the tracks should be approximately 1 second or 5 m (15 ft). There's no need to stop at every point, just continue driving.  At about 15 kph (~10 mph) recording every second you get around 5 m spacing.  If it is a lot smaller than (eg 1 m) then the number of survey points can become large and get slower for the software to handle and process for fields larger than 100ha (250ac).

  6. Ensure that the entire field has been covered. Do not skip parts of the field because they are inaccessible due to wet or muddy conditions; you are in a hurry; you think you do not have time to finish properly. This has a negative impact on the quality of your maps generated from your collected data. It is important to cover the entire field.

  7. It is also a good idea to survey the bottom of existing ditches and large depressions so that the terrain shape is correctly recreated in the design software.  Utilizing parallel tracking with straight track can cause the user to miss areas of interest for surveying, for example the bottom of a main ditch which can have an obvious width and depth.  Driving along the shoulder (top off batter) of large ditches can also be worthwhile to better define the shape of the topography.
Here is an image example of a good survey.

Tips and Tricks

  1. Settlement In Low Spots That Were Filled
  2. NRCS SCS Engineering Field Handbook
  3. Water Control Structures
  4. Smoothing Distance
  5. Erosion Control Banks & Waterway
  6. Drainage Design Solutions of Different Topographies
  7. Runoff vs Slope
  8. Trimble Field Level II Do Not Show the .gps File
  9. Minimum Recommended Smoothing Distance For Export To Trimble Field Level 2
  10. GPS Base Station Setup For Best Vertical Accuracy
  11. How to Survey with Trimble FMX
  12. How Easy is OptiSurface to Use for the Average Farmer?
  13. Balancing Earthworks in the Field
  14. Landform Design Slopes and Smoothing
  15. Export Proposed Topography to AutoCAD
  16. Surface Irrigation Designs with Variable Slope
  17. OptiSurface Designer Import and Export Format
  18. Importing Multiple Survey Files to OSD
  19. Can Drone Or LIDAR Surveys be used with OptiSurface?
  20. Calculation Grid Spacing and Export Grid Spacing
  21. How to Survey a Field for Landforming Design
  22. Loading .gps File in FMX
  23. Designing a Field in Sections
  24. Using an Old OSD File versus a New Survey
  25. No Master Benchmark on Imported Survey File
  26. Displaying Secondary Benchmarks
  27. Import Error for xyz File Due to Encoding Format
  28. OptiSurface4D: Bounded By Ridges
  29. Can OptiSurface handle curved rows in Drainage Analysis & Runoff Analysis?
  30. Reverse Grades to Main Slope
  31. Measuring Culvert Invert Level
  32. Surveying a 1000-Ha Field
  33. GPS Coordinate System Check
  34. Does A Normal UTM Zone Coordinate Need To Be Trimmed To x Digits?
  35. Can You Import Data Directly From GPS System?
  36. Converting Latitude/Longitude to Easting/Northing
  37. Surveying With Any GPS Equipment and Exporting to a gps file for the Trimble FMX
  38. DGPS Post Treating System with 5cm Precision For Landforming
  39. Exporting to Trimble FMX Field Level
  40. Can I Survey with a GPS System on an ATV?
  41. Standard NMEA GPGGA txt File to Import into OptiSurface Designer
  42. 900 Acres: Cut that large survey down.
  43. Export Options for Data Layers
  44. Import Two or More Survey Files to Reach Minimum Area
  45. Different Row Slope Directions In One Field
  46. Does OptiSurface allow for multiple grade breaks per design, taildrains roads, pads etc?
  47. Can I View DTM/Topography In Plan View Or 3D Type View When Doing A Design?
  48. Adjust the Bands in the Legend
  49. Design for a 1000-Ha Field
  50. Would It Be Possible That The Numbers In The Boundary Zone Appear In The New Subzone Created?
  51. Grade Of Best Fit And Splitting The Field Into Boundaries
  52. Acceptable Minimum Slopes
  53. Incorrect Area in OptiSurface
  54. Valley Subzone Not Behaving as Expected
  55. Difference Between Breaklines And Subzones
  56. Alignment of Furrow/Bed Direction with OptiSurface Design Mainslope Direction
  57. Subzones Settings Over Ride Boundary Zone Settings
  58. Printing the Maps
  59. Print Size

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