GRASS and LIDAR

Randal Halenorthrivergeographic.com

FOSS4G Boston 2017 August 14th - 18th

Seaport Hotel & World Trade Center

Boston, MA USA

● Workshops ● Cutting Edge Geospatial Talks ● Vibrant Community ● See Software/Data Standards and how they can work for you● Everything being done there is applicable to your situation● Do something Different for your “one big conference”.

Join the Southeast OSGEO Listserve

THERE WILL BE A CONFERENCE IN THE SPRING OF 2017 SOMEWHERE IN EAST TENNESSEE

Randal Hale

Owner/Operator/Janitor - NRGS

In operation for 10 years

Primarily using FOSS4G/Fulcrum/(little bit of ESRI)

Clients include:

● Forestry

● Territorial Gov’ts

● Counties

● Other Mapping Companies

● Utilities

What is FOSS4G?

Free and Open Source Software 4 GIS

Definition by Bruce Perens:

1. Free Redistribution 2. Source Code 3. Derived Works 4. Integrity of The Author's Source Code 5. No Discrimination Against Persons or Groups 6. No Discrimination Against Fields of Endeavor 7. Distribution of License 8. License Must Not Be Specific to a Product 9. License Must Not Restrict Other Software

10. License Must Be Technology-Neutral https://en.wikipedia.org/wiki/The_Open_Source_Definition

Geographic Resource Analysis Support System

● First Developed in 1982 by the US Army COE CERL (Construction Engineering Research Laboratory)

● Last US COE release was in 1992 at version 4.1 . USA-CERL stopped Active Development of GRASS for commercial software.

● Transferred to Open Grass Consortium in 1992

● 1999 GRASS 5 was released***

● 2006 OSGEO adopted GRASS

● 2010 Version 6.4.0 was Native Windows Compatible

● 2016 Version 7.0.5 Will be out shortly

GRASS - It boldly went where no GIS had gone before

GRASS Interface

GRASS Tools

Tools Available:

● Topology

● Networking

● Terrain Analysis

● Raster Calculator

● Watershed Tools

● Wildfire Modeling

● LIDAR

LIDARLight Detection and Ranging

State of Tennessee

● TN has a robust GIS Program

● Started in 1996 with Parcel Data Conversion

○ Finished around 2006

● 201x(ish) started collecting LIDAR/New Imagery

● State is now participating in 3DEP along with USGS and other partners. LIDAR will be free to Download and use. Accessed through tngis.org

● The Exciting part is the Generation of Derived Products

LIDAR in Tennessee

Why LIDAR and FOSS4G

● Most of my workflow is FOSS4G these days

○ FOSS4G support is community based. The community is wide and varied. It’s standards oriented.

○ It is Professional Software● Clients start turning up and asking about LIDAR. Which

means LIDAR has become commonplace

● Run into people doing a lot of work with LIDAR in the FOSS Community:

○ PDAL○ GRASS

LIDAR in GRASS

First Hurdle:

● LIDAR in TN is released in zLAS format and not LAS or LASz format.

● zLAS is a Vendor Specific Format used by ESRI. ○ Not open ○ Only used in ESRI products and Extensions

● I have to “jailbreak” the Format to get it into FOSS4G. ● RapidLasso released LASliberator

--------------RANT---------------

Sharing Data is an awesome thing and thank you TN for doing that

BUT

Zlas format is an unnecessary tax

You’re excluding everyone not on ESRI

You’re adding one step to get it out of zlas

It’s not an ASPRS standard

Please release it as lasz

TNGIS Server and LIDAR

LIDAR File

● Thankfully there is Metadata and from that:

● The LIDAR can generate a 5 foot pixel (if I’m understanding this correctly)

● The data was classified as follows*:○ Class 1 = Unclassified. This class includes vegetation,

buildings, etc.○ Class 2 = Ground○ Class 7= Noise○ Class 8= Model Key Points○ Class 9 = Water○ Class 12=Overlap Points (high scan angles)○ Class 13= Bridge Deck Points

*Which follows the LAS Standard

GRASS LIDAR Processing

Import your LAS or LASz file into GRASS using v.in.lidar

● 30984894 points

● Classes 2,8,9

● 11327257 imported

Commands used in this Demo

● v.in.lidar

● g.region

● v.surf.idw

● r.relief

Demo Time

YOU CAN DO MORE

● V.lidar.edgedetection

● V.lidar.growing

● V.lidar.correction

● Point Counts to see how many points per unit you have

● Spatio temporal analysis

● Solar analysis

More Tools coming with every release.

GRASS and Lidar: More is coming

Extreme thanks go to:

● Doug Newcombe - USFWS ● Vaclav Petras - NCSU/GRASS Developer ● Martin Isenburg - Rapidlasso and LAS Developer● USGS and TN

Thoughts, Anger, Questions, Joy?