Surveyor's Guide: From Drone Flight to Topographic Map

This guide walks you through a typical surveying workflow in Lidarvisor — from a raw LAS file off your drone to a professional topographic map and contour deliverable.

---

What You Will Produce

By the end of this workflow, you will have:

• A classified point cloud with ground, vegetation, buildings, and other features labeled
• A DTM (bare ground surface) with hillshade
• A DSM (top surface including trees and buildings)
• Contour lines at your chosen intervals
• An elevation grid for CAD spot elevations
• Building footprints
• A layered DXF topographic map combining all of the above — ready to deliver or import into CAD

With traditional desktop software, assembling these deliverables can take half a day or more of manual work. Lidarvisor does it automatically in minutes.

---

Step 1: Prepare Your Data

After your drone flight, export your LiDAR data as a LAS or LAZ file using your drone's processing software (e.g., DJI Terra, Livox Viewer, Emlid Studio, or similar).

Make sure:

• The file is in LAS or LAZ format (not a proprietary format)
• The coordinate system is embedded in the file, or you know the EPSG code used during the flight
• The data covers the area you need (check in your drone software before uploading)

Tip: LAZ files are compressed and upload much faster. If your software offers LAZ export, use it.

Step 2: Create a Project and Upload

1. Log in to cloud.lidarvisor.com.
2. Click Create a project.
3. Name it (e.g., "Smith Property Survey - March 2026").
4. Select your LAS/LAZ file.
5. Optionally add an orthophoto (TIFF) if you have one.
6. Click Import project.

Wait for upload, tiling, and metadata extraction to complete. Your point cloud will appear in the 3D viewer.

Step 3: Verify Your Data

Before spending credits, check:

• Does the point cloud appear in the correct geographic location? Toggle a satellite background map to compare.
• Do the points look reasonable? Zoom in and rotate to check for obvious issues (large gaps, wildly scattered points, or an empty area).
• Is the area shown in the metadata what you expected?

Step 4: Configure Processing Options

In the left panel, enable these options:

Terrain (Raster):

• Generate DTM — Resolution: 50 cm (good default for most surveys; use 25 cm for high-precision work)
• Generate DSM — Resolution: 50 cm

Vector:

• Generate Contours — Major: 500 cm (5 m), Minor: 100 cm (1 m). Adjust based on terrain relief — use smaller intervals for flat sites.
• Generate Grid — Resolution: 500 cm (5 m) for a spot elevation every 5 meters
• Extract Buildings — Simplification: Urban for city sites, Rural for isolated structures

Reports:

• Generate Topographic Map

Click Process Data and confirm the credit cost.

Step 5: Review Your Results

Once processing completes:

1. Switch to Classification mode to verify the AI correctly identified ground, buildings, and vegetation.
2. Check the DTM hillshade — toggle it on in the project tree and look for terrain features you recognize.
3. Toggle contour lines on — do they follow the terrain shape you expect? Are the intervals appropriate?
4. Check building footprints — do the outlines match the actual buildings?

Quick Fixes

Issue	Solution
Ground points misclassified as vegetation	Use the Height Tool to reclassify low points as Ground, then re-process
Contour intervals too wide or too narrow	Re-process with different Major/Minor interval values
Building outlines too simplified	Re-process with "Urban" simplification mode

Step 6: Download Deliverables

Deliverable	Where to Download	Format
Classified point cloud	Project tree → Classified Point Cloud → Download	LAZ (for archive) or LAS
DTM	Project tree → DTM → Download	GeoTIFF (in ZIP)
DSM	Project tree → DSM → Download	GeoTIFF (in ZIP)
Contour lines	Project tree → Contour Lines → Download	DXF for CAD, Shapefile for GIS
Building footprints	Project tree → Buildings → Download	DXF for CAD, Shapefile for GIS
Topographic Map	Project tree → Topographic Map → Download	DXF (layered, in ZIP)

Step 7: Share with Your Client

Click Share in the toolbar and send the link to your client. They can explore the full 3D point cloud and all results in their browser without creating an account — a great way to get feedback before finalizing deliverables.

---

Recommended Resolution Cheat Sheet

Site Type	DTM/DSM Resolution	Contour Major	Contour Minor
Flat residential lot	25 cm	1 m	0.25 m
Rolling hillside	50 cm	5 m	1 m
Large rural property	100 cm	5 m	1 m
Mountain terrain	100 cm	10 m	2 m

---

What This Replaces

In a traditional workflow, you would:

1. Import LAS into TerraScan or CloudCompare (~10 min)
2. Manually classify ground points, adjusting parameters iteratively (~1–4 hours)
3. Generate a DTM in Global Mapper or ArcGIS (~30 min)
4. Generate contours and clean them manually (~1–2 hours)
5. Extract building footprints manually or semi-automatically (~1 hour)
6. Assemble the topographic map in AutoCAD (~2–4 hours)

Total: 5–12 hours of manual work.

With Lidarvisor, steps 2–6 happen automatically in one processing run. Your main job is verifying the results and making minor corrections.