To begin your project, we will need to know the mapping location and boundary, the contour interval, and the map scale you will require. Our mapping professionals can help explain mapping accuracy standards if you are not familiar with them.
Once your needs are determined, Aerial Mapping Services will provide you with a project cost estimate and completion timeframe. We will also let you know the number of horizontal-vertical control points required so you can build this cost into your company's surveying estimate.
Once your project is awarded, we will provide to you a horizontal-vertical ground control point layout. This diagram shows a surveyor the optimal locations of ground control points based on your flight altitude and desired mapping accuracy. Ground control points must be surveyed very accurately as they directly influence the accuracy of our three-dimensional model setup and final digital mapping.
Next, horizontal-vertical ground control targets are placed on the ground and their x/y/z coordinates are shot in; this can be performed by your surveyors or ours. Although it is only necessary that the targets are in place (not yet surveyed) before your job is flown, we must receive the control point coordinates before we can begin digitally mapping your project.
Once your ground targets are set, our pilots will photograph your project from the air using a motion-compensated photogrammetric camera or LiDAR data collection system. Black-and-white or color photos of the area are taken and processed. If traditional film is used, your photos will be translated to a high-resolution digital format using our advanced photogrammetric scanning equipment.
Now that we have digital images and control point information, a three-dimensional digital representation of your project is set up on our state-of-the-art computer modeling systems. Analytics are performed to tie the aerial photographs into the control point database grid. Data points for the digital terrain model (DTM) are collected and/or filtered, and contours are generated using sophisticated mapping algorithms. Our experienced computer mapping specialists collect data points for land features such as roads, buildings, fences, signs, and hydrants using industry-accepted mapping symbols, with each object type on its own layer. (Just think of the time and money you will save by not tying up an entire survey team to collect this information in the field, and the ease with which you can find and view specific object types in the final digital file!)
A digital orthophoto may be created from the aerial photographs and digital models, according to your project's needs. An orthophoto is an aerial photograph that has been geometrically corrected, or orthorectified; it can be used to measure true distances because it accounts for land terrain, earth curvature, and camera/lens characteristics. It is extremely useful in presentations of your project to your client.
The final digital model of your project and other related files can be delivered to you in a variety of industry-standard file formats, including .dxf/.dwg (AutoCAD or CivilCAD) or .dgn (Integraph Microstation). Please talk to us about other file customizations you may require; we want you to be able to proceed with the next stages of your project design as quickly as possible after you receive our finished file.
And the whole time we've been doing all of this groundwork, your time has been freed up to take care of other important business, or to simply relax, knowing that Aerial Mapping Services has done all of the hard work for you!