1. Folder Structure, Terrain Feature Dataset, and Geodatabase Creation

Transcription

1 1. Folder Structure, Terrain Feature Dataset, and Geodatabase Creation You will be working with a lot of different files and it is important to keep them organized so that is easy to place and locate things. The best way to keep track of data and your calculations is to have a folder for your project that contains a data folder. A. Create a folder with the following subfolders: I. Data i. Data Geodatabase ii. Results Geodatabase a. Terrain Feature Dataset with the following properties: 1. XY Coordinates: NAD 1983 State Plane VA South FIPS 4502 (US Feet)/your local State Plane system 2. Vertical Z Coordinates: NAVD 1988 (add _Feet to name) **It would be useful to save these to Coordinate Systems as favorites I. Documents II. Downloads III. Maps B. Set your projection as StatePlane Virginia FIPS South 4502 (US Feet)/your local State Plane system Folder Setup Data Data Results Documents Downloads Maps Terrain 2. Downloads A. Go to earthexplorer.usgs.gov/ B. Create an account and remain logged in C. Click on Dataset Tab

2 D. Scroll down to LIDAR>Expand>Check Toggle Coverage Map box E. Return to the Search Criteria tab F. Click the predefined area tab I. Select add shape i. Fill in: 1. State: Virginia 2. Area type: County 3. Area: Colonial Heights City ii. Click Add **You should see a red triangle highlighting options for Colonial Heights G. Click on the Results tab H. Look for the LIDAR Entity ID: I. VA_FEMA_MIDDLECOUNTIES_2011_ **This should be the second on the list II. Click on the foot to show the footprint **You will now see a highlighted tile of LIDAR Data for Colonial Heights III. Click on the icon with a green arrow point down labeled Download Options IV. A box will pop up and click download I. Save the download into the suggested Download folder that was created J. Once the download has finished go to the download and locate the zipped file I. Right click and extract all **The extraction should default to wherever the zip file is located Make an account on Earth Explorer Download correct LiDAR entity into specified folder 3. LAS Dataset A. Create new LAS Dataset by right clicking the Data folder > New > LAS Dataset I. Name the LAS Dataset II. Right click the created LAS Dataset > Properties

3 i. LAS Files Tab: Add Files > Navigate to Downloads folder ii. Surface Constraints Tab: Add Study_Area from Data.gdb > Set as Hard Clip iii. Statistics Tab: Calculate Statistics iv. XY Coordinate System Tab: Projected Coordinate Systems > StatePlane > NAD 1983 (US Feet): NAD 1983 StatePlane Virginia South FIPS 4502 (US Feet) v. Z Coordinate System Tab: Vertical Coordinate Systems > North America > Double Click NAD 1983 > Change Meter to Foot_US under linear unit vi. Click OK B. Customize LAS Dataset Toolbar I. Click Customize > Toolbars > LAS Dataset II. Dock the LAS Dataset Toolbar III. Right click the Dataset and go to Properties i. Display > Change point limit value to 5,000,000 ii. Change point density to Fine iii. Check Use scale to control full resolution **Full resolution scale: 5,000 iv. Check Always display LAS file extents v. Click Ok Create new LAS Dataset with proper items Dock LAS Dataset Change LAS Toolbar settings

4 4. Pointclouds and Terrains A. Create new Pointcloud I. Search LAS to Multipoint using the Search tool and select LAS to Multipoint (3D Analyst) (Tool) i. Input: LAS File(s) ii. Output Feature Class: Terrain feature dataset > Name Pointclouddem iii. Average Point Spacing: 1.5 iv. Input Class Code: 2 (Ground) v. Coordinate System: Local StatePlane Coordinate System B. Create new Terrain I. Right click on Terrain feature dataset in Results.gdb > New > Terrain i. Name: pointclouddemterrain ii. Check pointclouddem and Study_Area iii. Approximate Point Spacing: 1.5 iv. Change Study_Area to Hard Clip v. Calculate Pyramid Properties vi. Finish and Build > Bring into Table of Contents

5 Create Pointcloud Create Terrain