Modern Survey.
Geospatial Intelligence.

What Is an Elevation Certificate and When Do You Need One?

An Elevation Certificate (EC) is an official FEMA form completed by a licensed surveyor. It documents your building's elevation relative to the Base Flood Elevation (BFE) — the height floodwaters are expected to reach during a 1% annual chance flood event (commonly called the "100-year flood").

You typically need one when: applying for or renewing flood insurance under the National Flood Insurance Program (NFIP), applying for a building permit in a Special Flood Hazard Area (SFHA), or appealing your flood zone designation to FEMA.

• NFIP flood insurance rate reduction
• Building permit applications in flood zones
• FEMA Letter of Map Amendment (LOMA)

LiDAR vs. Traditional Ground Survey: Which One Does Your Project Need?

LiDAR (Light Detection and Ranging) captures millions of elevation points per second using laser pulses, producing a dense 3D point cloud of your site. Traditional ground survey collects discrete points using total stations and GNSS equipment — far fewer points, but typically higher accuracy per point.

Choose LiDAR for large sites (>5 acres), complex terrain, dense vegetation, or when speed matters. Choose traditional survey for legal boundary work, small lots, construction staking, and anything requiring sub-centimeter accuracy.

ALTA/NSPS Survey Requirements: What Every Commercial Buyer Should Know

An ALTA/NSPS Land Title Survey is the most comprehensive survey standard in the U.S., jointly maintained by the American Land Title Association and the National Society of Professional Surveyors. It's typically required by lenders and title insurers for commercial real estate transactions.

Unlike a simple boundary survey, an ALTA shows easements, encroachments, setbacks, utilities, access, and much more — all per a standardized Table A of optional items negotiated between buyer, lender, and surveyor.

How to Read a Topographic Survey (And What Your Engineer Needs From It)

Contour lines connect points of equal elevation. The closer the lines, the steeper the slope. A topographic survey shows these contours, plus spot elevations, structures, trees, and utilities — giving engineers the data to design grading, drainage, and foundations.

• Contour interval: typically 1 ft for flat sites, 2 ft for rolling terrain in Florida
• Datum: NAVD 88 is the standard — make sure your survey matches your permit drawings
• Deliverable: ask for DWG + LandXML surface for Civil 3D import

Boundary Survey vs. Survey Sketch: What's the Difference and Which Do You Need?

A boundary survey is performed by a licensed Professional Surveyor & Mapper (PSM), involves fieldwork, establishes legal corners, and results in a sealed document admissible for permits, closings, and legal proceedings.

A survey sketch (or mortgage survey) is a non-certified diagram prepared from existing records — cheaper, but not legally binding and often insufficient for permitting or dispute resolution.

Drone Survey Accuracy: What GSD, GCP, and RTK Actually Mean for Your Data

Not all drone surveys are equal. GSD (Ground Sampling Distance) is the size of one pixel on the ground — smaller is sharper. For engineering-grade work, aim for 2–3 cm GSD. GCPs (Ground Control Points) are GPS-surveyed targets that anchor your drone data to real-world coordinates.

RTK (Real-Time Kinematic) GPS on the drone eliminates the need for many GCPs by computing centimeter-accurate position in real time. EA Mapping uses RTK-enabled drones with checkpoints to verify accuracy on every flight.