The first step: creating preliminary project boundary based on client's needs. We'll investigate all possible data sources
(from public to our internal collection of imagery), determining what data needs to be acquired.
Flight plans are created to cover the project area and estimates given. A lot of variation is involved to produce the intended results.
If photos are preexisting, PID (photo ID points) must be picked - which can be both seen from the photos... and measured accurately on the ground.
If no imagery yet exists, the option to lay ground panels is available (typically needed in more undeveloped areas).
PIDs and/or panels are visited with high accuracy (mapping grade) GPS equipment, where coordinates are recorded.
Aerial photography is now ordered to our exact specifications and inspected.
Specialized technicians known as Photogrammetrists "bridge", or connect the photos together, via picking and measuring common points.
Pass points link images within the same flight line together, whereas tie points join different flight lines (if multiple lines were needed).
Control data acquired with GPS is added to the "solution", effectively pinning down the imagery to known ground points. The result: a geographically aware mesh of overlapping imagery, the main ingredient for the next step.
Using highly specialized workstations, vector data (points, lines & polygons) are drawn on top of imagery in 3D which represent ground features (buildings, roads, utilities, vegetation, etc.). This data is referred to as planimetrics.
To create an elevation file, more 3D data (mass points & breaklines) are drawn, which represent detailed ground characteristics (ridges, ditches, mounds, pits, etc.).
Data from the stereo-models are combined, revisions made, and final planimetric and/or topographic product produced.
(This is where quality control and format conversions take place).
Project boundary, images and elevation files (breaklines, mass points, LiDAR, gridded DTM, etc.) are gathered.
Elevation files are adjusted as needed, specifically for purpose of producing an accurate ortho.
Previously triangulated and controlled imagery is dodged and color balanced if needed.
Images are warped with the elevation data, effectively draping the image over the 3D digital model.
Stiching the clipped images together and the final product to the project boundary. Graphics editing is final step.
The final product is commonly a georeferenced raster file, or a large-scale plot.
LiDAR point clouds, TINs (Triangulated Irregular Network), breaklines, topo/relief maps, contours, DEM and DTM grids
DGN, DXF, DWG, Shapefile, Geodatabase, Excel spreadsheet, etc.
GEOTIFF, SID, ECW, JPG
Water, Storm Water, Sewer, Electric, Gas, Cable, Fiber Optic, etc.
High quality maps of any subject/zoom level
Residential land development maps track progress in any chosen metric
Copyright © 2022 Avioimage - All Rights Reserved.