CONDUCTING A LiDAR PROJECT AND WHAT YOU CAN DO WITH … · 2015-12-11 · Standard LIDAR – Nominal 1m point spacing 15 cm RMSEz vertical accuracy Hydro Enforced breaklines 20 foot

CONDUCTING A LiDAR PROJECT AND WHAT YOU

CAN DO WITH THE DATA

CHRIS GUY

LIDAR PRODUCTION MANAGER

Meeting The Needs Of The Project

Choosing Appropriate System And Platform

Project Planning Methods

Processing Workflow

Resources Necessary To Meet Schedule

Applications

Advantages of LiDAR

Software

Outline

Meeting The Needs Of The Project

Transportation

Contours

Transmission Lines

Contours

Volumes

Buildings

Feature Extraction

Vegetation

Erosion

Deciding Accuracy and Application

Appropriate Platform

Helicopter

Airplane

Train

Boat

Automobile

Tripod

Choose the Correct Sensor

Large area sensor – Leica ALS70

Corridor sensor - Optech Orion

Mobile LiDAR sensor- Optech Lynx

Fixed tripod scanner

Cameras to support the LiDAR

LiDAR Project Planning

Plan based on

Flightline distance limitations

Workable blocks of data

Delivery tiles

Baseline requirements

Control locations

Accuracy

Application

Topography

• Day or Night

Safety considerations

• Leaf on or Leaf off

Application dependent

• Summer, Spring, Fall, or Winter

Most collects done in the spring and fall

Summer collects take place for special

applications such as forestry

Winter collects based on geographic

location

• Weather

• Smoke

LiDAR Project Planning

Establish a Flight Plan

• Altitude

• System PRF

• Scan Angle

• Speed

• Overlap

Standard LIDAR – Nominal 1m point spacing

15 cm RMSEz vertical accuracy

Hydro Enforced breaklines

20 foot nominal widths for rivers

1 acre lakes/ponds

General-use, Meets most needs for LiDAR-based DEM

USGS Compliant LIDAR – Nominal 1m – 2m point spacing

15 cm RMSEz Vertical Accuracy

Hydro Enforced Breaklines

100 foot nominal widths for rivers

2 acre lakes/ponds

Points removed off breaklines in separate class

1m – 3m DEM

Metadata

Processing and Vertical Assessment Reports

High Accuracy LiDAR – 0.7m or more Point spacing

9.24 cm RMSEz

Supplemental 1 foot accuracy specifications

50% overlap for very dense vegetation

Supplemental breaklines

Vertical Assessment Report provided

Requires very good calibration: Keep overlap

LiDAR Specifications

Terrain Impacts Collection and Processing Techniques

Swath Gap?

Possible Void Area

Flightlines with Proposed Base Stations

Data collection as required by client

Contour products

Sample density – 8 points per meter and higher

3-D building extraction

Clients requiring

additional classification

Water

Vegetation

Buildings

Planning Specialized LiDAR

Review and Initiate Project

Area 7,754 square miles

Flying Height 1,500 meters

Ground Speed 160 knots

Flight Line Sidelap 50%

Pulse Repetition

Frequency 70 KHz

Scan Angle 40° (total)

Scan Rate 35 Hz

Proposed Tile Format 2000 ft x 2000 ft

Total Number of Tiles 54,064 tiles

Units US Survey Feet

Project Work Flow

LiDAR Acquisition (field)

Control Survey (field)

Airborne or Mobile

GPS/IMU

Output LAS

Mission Calibration

Build Project

Classify LiDAR point cloud

Create Deliverables

Flight Plan Overlay On Imagery For Estimating

Establishing Control

Check Point Surveys

Five Main Categories

Hard Surface

Low Grass

High Grass

Brush

Forest

What does this mean?

By region?

Point distribution?

Verification of Point Class

Legend High Vegetation Points

Medium Vegetation Points

Bare Soil points

GPS/GNSS Processing

• Launch GNSS Processor

• Convert Raw data files to

GPB format

• Aircraft

• Base Station

• Published Position and

Antenna Height and Type

LiDAR Processing - Processing

Checking Calibration Differences between bad calibration and correct calibration

Unresolved Area Resolved Area

Checking Calibration DZ ortho from several missions

All Points Surface Before Point Classification

Surface After Classifying Points To Ground

Surface From Point Cloud Classified to Ground

Applications

Hydro Breakline Collection Process (LiDARgrammetry)

Additional Classification

• Smooth Water Bodies

• Vegetation - Low, Medium, High

• Buildings - Points, Footprints

More Detailed Line work Buildings, Curbs, Oil Tanks, Road Center Lines

Further Classification Techniques

Class Examples

-Building

-Ground

-Water

-Non Ground

-Above or Below Ground

-Transmission Lines

-Pipeline

-Rails

DAM Management

DSM- Digital Surface Model Intensity Image

Building and Vegetation Extraction

3-D Buildings

Airborne -Planemetrics

LiDAR of Bridge at 0.3 meter collection

LiDAR of Mile High Stadium

Airborne- Security Management

Airborne – As Built

Airborne – Transmission Mapping

Airborne – HCA and Risk Analysis

Pipeline Mapping

Materials calculations – construction

Site Design

Airborne – Change Detection

Contour and Orthorectification Generation

Filtered Bare Earth LiDAR & LiDAR DEM

Bare earth surface model Contours draped on surface Contours

Photography draped over

LiDAR data Contours draped over

orthophotography

Terrestrial LiDAR –Construction and Engineering

44

Terrestrial LiDAR (AEC) Architecture, Engineering, Construction

45

Terrestrial AEC Architecture, Engineering, Construction

46

Terrestial Emergency Management

47

Terrestrial -Transportation

48

Terrestrial -Accident Reconstruction

49

Rail Survey

Rail Survey – Image fused with LIDAR

Terrestrial LiDAR

Levee – Picked up cracks in the pavement on the levee

Terrestrial LiDAR

Geomorphology- Coal veins

Terrestrial and Helicopter

Transmission

3D models and Site design

3D Modeling

Survey-Grade Contour and Planimetric

Data

Advantages of LiDAR over Photogrammetry

Collection day or night

No sun angle requirements

Ground data through canopy

Measure heights of canopy

Accurate surface models in forest

Thank You