How to choose the best Mapping and Survey Technology for your large-scale mining or mapping project.

By February 3, 2020 Uncategorized No Comments

With recent and ever evolving surveying and mapping technology it can be a very daunting task to decide the most appropriate approach to a mapping project. Working with a skilled surveying or mapping firm knowledgeable in the most current technologies is crucial to help the client determine the best approach. If you are looking for a survey company between Vernon and Kelowna some considerations that should be asked by the surveying firm should include:

  • What kind of accuracy is required for the project?
  • Is the data set/deliverable going to be used for conceptual or detailed design work?
  • How dense is the vegetation and tree cover?

The most common solutions for large-scale mapping solutions include:

  • Real Time Kinematic GPS surveys
  • Topographic Surveying
  • Unmanned Aerial Vehicle (UAV) or Unmanned Aerial System (UASs) photogrammetry
  • Unmanned Aerial Vehicle (UAV) or Unmanned Aerial System (UASs) LiDAR
  • Laser Scanning
  • Hydrographic/Bathymetry Surveying

Most large-scale mapping projects include a combination of survey technologies. Below is a brief overview.

Real Time Kinematic (RTK) surveying

RTK surveying is a relative position technique that requires two survey grade GPS receivers. One receiver is static and setup on either a known coordinate or an assumed coordinate that can later be processed to the desired projection and scale. This receiver is known as the Base Station. The second receiver, known as the Rover, is with surveyor and taking the survey measurements. The Rovers position is being calculated Real Time relative to the base position. Multiple rovers can be connected the base station simultaneously collecting data. This is a very accurate mapping technique and provides the a very high confidence level by having ‘boots on the ground’.

GPS Receivers can also be mounted to an ATV or other vehicle and can be set to collect measurements while the vehicle is in motion at defined time or distance intervals. This is a great option for sites that are very accessible.

RTK survey receivers can also be used to complete Bathymetry surveys below water surface. The Rover is linked, usually via. Bluetooth to a survey grade sonar that is constantly measuring the range from the sonar Transducer to the bottom of the water body. Data Collection software is used that collects the depth and the measurement to the GPS antennae. Real time depth measurements are collected for later processing and modeling.

Drone Mapping and Surveying

OSDC offers Drone and Aerial Photomapping services from our Kelowna office. Aerial Mapping Drones allow us to cover vast amounts of area in a very short amount of time with a high level of accuracy. The two main types of Aerial Mapping Services for mining include:

Unmanned Aerial Vehicle (UAV) or Unmanned Aerial System (UASs) photogrammetry mapping

Photogrammetry is the art and science of creating 3D models from photographs.

With recent advancements in the Unmanned Aerial Vehicles (UAVs) or Unmanned Aerial Systems (UASs) it is now possible to very accurately map hundreds of acres of land in a single day.  UAV Mapping is becoming extremely popular for mapping mines, gravel pits, rock quarries and construction sites.  By mounting a camera on an Aerial Vehicle and collecting hundreds of images per acre. The images are stitched together using specialized software to create one large Orthomosaic or Orthophoto by matching and marrying the pixels in each individual image. An Orthophoto is a Geometrically corrected and uniformly scaled image. The main deliverable from this type of mapping include a High Resolution Orthophoto, 3D model and a dense point cloud. This type of mapping can produce a 3D model consisting of hundreds of data points per square meter and is ideally suited to a site that has been stripped of trees and vegetation.

To Orthorectify photogrammetry datasets Ground Control Points (GCPs) are set using either Real Time Kinematic (RTK) or Static GPS observations at aerial markers within the mapping area. These targets are typically large targets with a bullseye that will show up in the Ortho mosaic.

Photogrammetry software takes all the images and matches the pixels in each individual to create an orthoimage or mosaic. The orthoimage is then aligned and scaled to Ground Control Points (GCPs) typically set by Real Time Kinematic (RTK).

We always validate our Photogrammetry projects by taking many RTK GPS measurement at random positions throughout the project. These points are used to provide a high level of confidence in our data sets

Unmanned Aerial Vehicle (UAV) or Unmanned Aerial System (UASs) LiDAR mapping

LiDAR is a remote sensing technique that stands for Light Detection and Ranging. This method uses pulsed laser beams to measure ranges (variable distances) to the earths surface. LiDAR energy can penetrate the forest canopy meaning you are able to take ground measurements in forested areas.  LiDAR technology receives multiple measurement returns meaning models can be created for Tree Canopy Height Models as well as Digital Elevation Model (DEM).

It is very important to do your research prior to hiring a service provider for any surveying or mapping project. Many businesses offer just UAV mapping and sell it as being a one stop solution for all mapping needs. It is important to know the limitations of any technology and even more important to hire a professional, knowledgeable and reputable surveying firm.

OSDC provides Aerial Mapping services throughout Kelowna and all of the Okanagan area including Vernon, Lumby, Peachland, Penticton, Oliver and Osoyoos.

Bathymetric Surveying

Bathymetric surveying techniques allow us to map the underwater surface of a waterbody. Most commonly in mining, bathymetry surveying is used map the floor of tailings ponds. Using bathymetry   surveying techniques, we can produce extremely accurate mapping of the floor to determine important information including sediment buildup and monitoring as well as storage capacity.

The two most common sensors used for bathymetry surveying include:

Single Beam Echosounder

Single Beam Echosounders measure the travel time of a sonar pulse from the unit’s transducer that is set just below the water surface. The unit communicates with a GPS Receiver or a prism communicating with a Robotic Total Station.  The Single Beam Echo Sounder communicates with Data Collection Software which will record Real Time measurements of the bottom surface of a water body.  The system is typically setup on a manned boat or pulled across a river or creek channel using taglines.  The data collection software is set to record either a measurement at either a time or distance interval.

Multi Beam Echosounder

Multi Beam Echosounders emit sound waves in a fan shape. Depths are determined by measuring the time it takes for a sound wave to return to the receiver unit. Multibeam Echosounders are typically used to measure tidal water bodies.

 Topographical Surveying and Mapping

Topographical Surveys are a 2-dimensional plan view representation showing the elevations and surface features of a piece of land.  Due to the inconsistent terrain in Kelowna and the Okanagan valley a detailed topographic survey Is typically the first step in any development project. The main components of a topographical map include:

Contour lines

Contours are a horizontal line connecting points if equal elevation. Using a contour map the steepness of terrain can very easily be interpreted. The closer the lines the steeper the further apart the flatter the land is. Contour intervals are decided upon during the drafting stage depending on the scale of the map and topography.

Surface/Man Made Features

As part of a topographic survey surface features are typically surveyed. These typically include things such as utility boxes, manholes, curbs, light poles, signs, asphalt, services and buildings.

Environmental and Water Features

Creeks, watercourses and vegetated/brushy areas. These areas are typically very sensitive to any type of mining or development work

If you are looking for a topographic survey in Kelowna consider OSDC.

Environmental and Water Features

For modeling purposes it is very critical to pickup surface break lines such as tops and bottoms of banks. These are important features for design proposes as well as creating an accurate contour map.

If you are considering hiring a survey company in Kelowna for a mapping project be certain they are familiar and proficient with the most current surveying technology. Services we offer from our Kelowna office include:

  • Aerial Photomapping Services
  • Aerial Mapping Services
  • Drone Mapping Services
  • Topographic Survey services
  • Bathymetry/Hydrographic surveying services