Elevation data collection that compresses days of ground crew time into a single flight — DSM, DTM, and contour datasets handed off to your licensed surveyor or engineer. Flown across Fort Lauderdale, Miami, and West Palm Beach and throughout Broward, Miami-Dade, and Palm Beach counties.
This needs stating before anything else, because it defines how the service works. Sellers LP is a data collection provider. It flies the site, processes the imagery into elevation products, and hands off the dataset. It does not stamp, seal, sign, or certify survey deliverables, and it never will.
The certifying party is the licensed surveyor or professional engineer on your side. They specify the accuracy requirement, they validate the delivered dataset against their own checks, and they carry the professional responsibility for whatever is issued from it.
That boundary is not a limitation to work around — it is what makes the arrangement clean. You get aerial collection at a fraction of the field time, and your licensed professional retains the control and responsibility that only they can hold.
A digital surface model records elevation at the top of everything the sensor sees — bare earth where there is nothing on it, but rooftops, canopy, equipment, and stockpiles where there is. It answers what the surface of the site looks like right now, which is what you want for volumetrics and clash checking.
A digital terrain model is the ground surface with above-ground features removed through processing. It answers what the land itself does, which is what feeds grading design, drainage analysis, and earthwork planning.
Contours are generated from the terrain model at whatever interval the project calls for and delivered as DXF or SHP, dropping straight into Civil 3D or a GIS environment. In South Florida, where meaningful elevation change across a site is often measured in inches rather than feet, contour interval selection matters more than it does in most of the country, and it is set to what the engineering actually needs.
Relative accuracy is the standard workflow. Measurements are internally consistent across the dataset, which is sufficient for progress tracking, site documentation, volumetric work, and general mapping support.
Survey-grade collection requires ground control points physically placed and surveyed on site, processed into the dataset alongside RTK corrections from Florida's open NTRIP network. That combination is what ties the model to absolute real-world position rather than just internal consistency.
Which you need is your surveyor's or engineer's call, not a decision to make on price. Specifying survey-grade where relative would do wastes money; specifying relative where survey-grade is required produces a dataset that cannot be used.
Ideal for: Licensed land surveyors, professional engineers, civil engineering firms, site developers, and earthwork contractors.
Elevation data feeds design, permitting, earthwork, and drainage analysis wherever ground truth is needed faster than a field crew can walk it.
No. Sellers LP collects and processes the aerial data and hands off the dataset. The licensed surveyor or professional engineer on your team validates it and is the certifying party for anything issued from it. This applies at every accuracy level, without exception.
A digital surface model includes everything above ground — buildings, vegetation canopy, equipment, stockpiles. A digital terrain model has those removed to leave bare earth.
You want the surface model for volumetrics and clash checking, and the terrain model for grading, drainage, and earthwork design.
It depends on the workflow. Relative accuracy means measurements are internally consistent across the dataset. Absolute survey-grade accuracy requires ground control points placed and surveyed on site alongside RTK correction.
Your licensed professional specifies which the project requires and validates the result.
Whatever the project specifies. In South Florida, total relief across a site is frequently small enough that interval selection materially changes whether the contours are useful, so it is set to the engineering requirement rather than a default.
DXF and SHP as standard, which import directly into Civil 3D, AutoCAD, QGIS, and ArcGIS. Surface and terrain models are delivered as georeferenced raster data.