top of page

SURVEY

Plan your builds better with more reliable and accurate information.

HOW IT WORKS

WHAT IS A SURVEY ?

Surveying is the technique and the science of measurement, particularly for our cases, regarding physical objects and areas of interest in the field. Generally, surveying spans a wide spectrum of use cases, ranging from legal documentation of land ownership, to the modeling of subsurface geology for hydrocarbon mining. At Tenbo Air, we integrate the techniques of aerial photogrammetry with high-accuracy and high-precision ground GPS, and spatial analytics, to produce well-scaled and globally-controlled 3D models of objects and areas. We can then derive any variety of reliable measurement from these 3D models (volumes, distances, quantified relief, temperature variation, etc).

PROJECT PLANNING

Digitally representing a 1-foot diameter pipe is very different than a 150-foot quarry high-wall, and the use-cases for both surveys likely have different accuracy requirements. The process of building a high-quality 3D model starts with understanding the object of interest (the "target"), and gaining a high respect for use-case accuracy requirements and the variables that are likely to introduce error. When you engage Tenbo Air on a survey project, we will first have a detailed requirements gathering discussion to intimately understand the target and your end use-case. These preliminary discussions will impact what follows: data acquisition efforts in the field, control and quality assurance requirements, and finally the building and refining of the digital model itself.

DATA ACQUISITION: PHOTOGRAMMETRY

The surveys we produce are copies of what exists in the real world. For the majority of our clients' cases, our goal is to present a highly accurate and realistic digital representation of the target given the budget and technology available, thereby minimizing the need for human value judgements in post-processing. Our process combines a data-collection and processing science called photogrammetry with ground-based survey control. In accordance with requirements set in the project planning stages, our field engineers collect hundreds (sometimes thousands) of high-resolution RGB or thermal images with high overlap, at various distances from the target, and at various angles around the target. In addition to these aerial and ground based images, our field engineers will typically scour the target and surrounding areas to collect survey-grade GPS coordinates.

DATA ACQUISITION: GROUND-TRUTHING

In addition to aerial and ground based image collection, our field engineers will typically scour the target and surrounding areas to collect precise distance measurements and survey-grade GPS coordinates on the ground, accurate in the real world to fractions of an inch. In the engineering world, this is a process called "ground-truthing", leaving little doubt about the model's degree of accuracy (or lack thereof) relative to what is actually on the ground at the time. This highly accurate real-world data is integral for assuring quality and accuracy in the post-processing stages.

PROCESSING AND ANALYTICS

After data has been thoroughly reviewed in the field for completeness and quality, the data is handed over to the Tenbo Air analytics team for additional review and processing. The photogrammetry and survey data is loaded into local and cloud-based photogrammetry engines, which tackle the arduous and time-consuming tasks of stitching individual images together and building a densified point cloud representation of the object. The resulting point cloud is the 3D model's mathematical skeleton, comprised of millions of points each with an accurate 3D location (x , y, and z coordinates). Lines and shapes can be layered around and between these 3D points to build an accurate representation of the object's surface. Trained analysts monitor the progress of the point cloud build. Additional data such as known dimensions on the ground and survey-grade GPS coordinates are integrated with the point cloud data to further constrain the model and optimize accuracy. Analysts can then proceed to build derivative datasets such as contour maps, elevation models, difference grids, and edited point clouds.

DELIVERY

Once our analytical efforts have been exhausted given the known requirements , the 3D model and derivative datasets are delivered to the project stakeholders and subject matter experts for review. Understanding of the project environment, end use-cases, and accuracy requirements frequently evolve over the project lifetime, so we aim to deliver assets ahead of the original schedule to allow for a sufficient review period and if necessary, a re-analysis of the data and revisions to the model outputs.

SURVEY IN ACTION

Below are a few survey projects we've worked on. Hover over the project icon to learn more about that project.

bottom of page