Surveying Articles

The following list is a very simple explanation of each of the types of surveys that are talked about here. As you can see, some types of surveys are known by multiple names. These can change in different parts of the country. I’m offering this as an initial list. Please let me know if you have any additions, corrections, or clarifications that need to be made to any of these.

Standard Types of Surveying:

ALTA Land Survey - more specifically known as an ALTA/NSPS Land Title Survey and done according the likewise named Standards developed by the two organizations.

As-Built Survey - a survey to determine the as-built location (horizontal and/or vertical) of any improvements that have been constructed.

Boundary Survey - aka Property Survey, Cadastral Survey - this type survey typically is done to find the property corners and/or lines for a parcel of land.

Cadastral Survey - see boundary survey.

Construction Survey - aka Construction Staking, Stakeout - setting reference points for defining the location of certain improvements that are planned. This normally includes both the horizontal location as well as the elevation (vertical location.) Construction surveys are also done in order to determine quantities for progress payments on a construction site. This may also be called an as-built survey.

Condo Survey - a specific type of survey of a condominium unit which not only locates the unit horizontally, but also vertically. A condo is typically owned from floor to ceiling and inside the walls.

Elevation Survey - aka Flood Survey, FEMA Flood Elevation Survey - done to determine the relative location of a structure or land with the Base Flood Elevation, as previously determined. The results are documented on an Elevation Certificate.

Elevation Certificates - FEMA form used to document the results of an Elevation Survey or Flood Survey.

Engineering Survey - done at the request of engineers in order for them to be able to design some type of project. These typically include the property boundary, a topographic survey, as-built locations of any utilities in the area or off-site that have to be extended to the site, easement locations, and any environmental issues located on the site.

Lot/Block (Plat) Survey - aka Mortgage Survey or Closing Survey - a survey of a platted lot in a subdivision. Plats are typically recorded in the local courthouse and contain multiple lots assumed to be created all at the same time.

Mortgage Survey - see Lot Survey

Pipeline Survey - see Route Survey

Route Survey - the survey of a linear route of an improvement, like a roadway, a railroad, or a pipeline. A major difference is that the route is measured along any curve in the alignment and not always on a straight line. Routes also typically use STATIONS to express the length along an alignment.

Right-of-Way (R.O.W.) Survey - done in order to establish or re-trace the location of a public or private right-of-way.

Subdivision Survey - done in order to create a subdivision of a larger tract of real property into smaller units, usually called Lots. See Lot Survey.

Topographic Survey - to collect points on the ground surface and improvements in order to provide a topographic or contour map. Includes the planimetric and elevation features of a parcel of land. The electronic form is known as a DTM (digital terrain model), a DEM (digital elevation model), or a TIN (triangulated irregular network.)

Wetland Survey - done to locate the boundary of wetlands, as delineated by wetland professionals.

Specialized Types of Surveying:

3D Laser Scanning - aka High-Definition Surveying (HDS) - a technology that uses a precise measurement scanner to digitally capture the shape of physical objects using laser lights. The scanned 3D points create a point cloud that can be used to produce 3D models of surfaces for multiple uses.

Aerial Photo Control Survey - the setting or location of aerial photo identifiable points that aid in the triangulation process necessary in completing a photogrammetry project.

Cartography - the study and practice of making maps.

Deformation Survey - aka Deformation Monitoring - done to determine if there is any movement over time of the earth or any structure built on the earth’s surface. The movement is aka subsidence or upheaval and can take place suddenly or gradually.

Geodetic Survey - land surveying over a larger area or distance wherein the curvature of the earth is taken into account.

GIS Mapping - gathering the location of objects that will be incorporated into a Geographical Information System (GIS). Other information about each object may also be collected as it is inventoried. This information is entered into a database that is tied to the map location, which is the definition of a GIS.

Gravity Measurements - made using a gravimeter in order to determine the gravitational field strength in a specific location. Related to Geophysical Surveys.

Hydrographic Survey - aka Bathymetric Survey - measurement and description of features below the surface of water. You can think of this as an underwater topo survey. These are carried out with specialized equipment designed for this work.

Land Planning - aka Urban Planning or Land-Use Planning - the process of planning the layout and division of a parcel of land to achieve its highest and best use. Planners try to be conscious of environmental issues, recreational features, transportation impacts, and economic factors when planning a land development project. Sometimes also municipal or regulatory restrictions have to be weighed along with the planning process and may affect the final plan.

Letter of Map Amendment (LOMA) - process used by FEMA to make changes to an existing flood map that may have been drawn incorrectly. When done properly, this removes a structure from the flood hazard zone permanently.

LiDAR Mapping - using Light Detection and Ranging remote sensing methods to create a point cloud of 3-D points. The LiDAR sensor can be elevated by a plane, helicopter, or drone, or can be stationary to the ground. (See 3D Laser Scanning)

Liquor Survey - a specific purpose survey to locate a proposed liquor sales location with other restrictive places like a church or school.

Mining Survey - the practice of determining the relative positions of points beneath the earth’s surface. These are typically done with much shorter tripods than regular surveying.

Orthophoto Creation - the process of creating a geometrically corrected (orthorectified) photo such that the scale is correct in plan view. Objects can be measured from an orthophoto with little distortion.

Point Cloud Creation - the process of taking a series of laser scanned “scenes” and seaming them together to create a coordinated point cloud of a larger area or object. For example, a point cloud of a 4-sided building may require 6 or more scenes (setups) in order to completely capture the building.

Survey Expert Witness - expert consulting and/or testimony given in a deposition or courtroom on a case involving subjects in which the professional is accepted as an expert. A fact witness only gives the results of some measurement that she is licensed to take. No opinion can be given unless that professional is qualified as an expert.