{ "cells": [ { "attachments": {}, "cell_type": "markdown", "metadata": {}, "source": [ "# Getting Started with GEDI L2A Version 2 Data in Python\n", "### This tutorial demonstrates how to work with the Elevation and Height Metrics ([GEDI02_A.002](https://doi.org/10.5067/GEDI/GEDI02_A.002)) data product.\n", "The Global Ecosystem Dynamics Investigation ([GEDI](https://lpdaac.usgs.gov/data/get-started-data/collection-overview/missions/gedi-overview/)) mission aims to characterize ecosystem structure and dynamics to enable radically improved quantification and understanding of the Earth's carbon cycle and biodiversity. The GEDI instrument produces high resolution laser ranging observations of the 3-dimensional structure of the Earth. GEDI is attached to the International Space Station and collects data globally between 51.6 N and 51.6 S latitudes at the highest resolution and densest sampling of any light detection and ranging (lidar) instrument in orbit to date. The Land Processes Distributed Active Archive Center (LP DAAC) distributes the GEDI Level 1 and Level 2 Version 1 and Version 2 products. The L1B and L2 GEDI products are archived and distributed in the HDF-EOS5 file format. \n", "\n", "---\n", "## Use Case Example: \n", "This tutorial was developed using an example use case for a project being completed by the National Park Service. **The goal of the project is to use GEDI L2A Version 2 data to observe tree canopy height and profile over Redwood National Park in northern California.** \n", "\n", "This tutorial will show how to use Python to open GEDI L2A Version 2 files, visualize the sub-orbit of GEDI points (shots), subset to a region of interest, visualize GEDI canopy height, and export subsets of GEDI science dataset (SDS) layers as GeoJSON files that can be loaded into GIS and/or Remote Sensing software programs. \n", "\n", "- [Redwood National Park GeoJSON](https://github.com/nasa/GEDI-Data-Resources/Additional_files/RedwoodNP.geojson) \n", " - Contains the administrative boundary for Redwood National Park, available from: [Administrative Boundaries of National Park System Units 12/31/2017 - National Geospatial Data Asset (NGDA) NPS National Parks Dataset](https://irma.nps.gov/DataStore/DownloadFile/594958)\n", "- [waveform.csv](https://github.com/nasa/GEDI-Data-Resources/Additional_files/waveform.csv) \n", " \n", "*** \n", "### Data Used in the Example: \n", "- **GEDI L2A Elevation and Height Metrics Data Global Footprint Level - [GEDI02_A.002](https://doi.org/10.5067/GEDI/GEDI02_A.002)**\n", " - _The purpose of the L2A dataset is to provide waveform interpretation and extracted products from each GEDI waveform. This includes ground elevation, canopy top height, relative return energy metrics (describing canopy vertical structure, for example), and many other interpreted products from the return waveforms._\n", " - **Science Dataset (SDS) layers:**\n", " - /rh \n", " - /elev_lowestmode \n", " - /elev_highestreturn \n", " - /lat_lowestmode \n", " - /lon_lowestmode \n", " - /shot_number \n", " - /quality_flag \n", " - /digital_elevation_model \n", " - /degrade_flag \n", " - /sensitivity \n", " - /selected_algorithm\n", "*** \n", "# Topics Covered:\n", "1. [**Get Started**](#getstarted) \n", " 1.1 Import Packages \n", " 1.2 Set Up the Working Environment and Retrieve Files \n", "2. [**Import and Interpret Data**](#importinterpret) \n", " 2.1 Open a GEDI HDF5 File and Read File Metadata \n", " 2.2 Read SDS Metadata and Subset by Beam \n", "3. [**Visualize a GEDI Sub-Orbit**](#visualizeorbit) \n", " 3.1 Subset by Layer and Create a Geodataframe \n", " 3.2 Visualize a Geodataframe\n", "4. [**Work with GEDI L2A Data**](#L2A) \n", " 4.1 Import and Extract Specific Shots \n", " 4.2 Plot Relative Height Metrics \n", " 4.3 Combine RH Metrics and Waveforms \n", " 4.4 Select Data from non-Default Algorithm \n", "5. [**Plot Transects**](#plottransects) \n", " 5.1 Quality Filtering \n", " 5.2 Plot Beam Transects \n", " 5.3 Subset Beam Transects \n", " 5.4 Plot RH Metrics Transects \n", "6. [**Spatial Visualization**](#spatialvisualization) \n", " 6.1 Import, Subset, and Quality Filter all Beams \n", " 6.2 Spatial Subsetting \n", " 6.3 Visualize All Beams: Canopy Height and Elevation \n", "7. [**Export Subsets as GeoJSON Files**](#exportgeojson) \n", "***\n", "# Before Starting this Tutorial:\n", "\n", "This tutorial requires a compatible Python Environment and GEDI L2A Version 2 granule from June 19, 2019 (orbit 02932, sub-orbit `02`) to download. To setup the Python environment and download the file, follow the steps in sections 1 and 2 of the [set-up instruction](https://github.com/nasa/GEDI-Data-Resources/Setup/setup_instructions.md). \n", "\n", "## Source Code used to Generate this Tutorial:\n", "The repository containing all of the required files is located at: https://github.com/nasa/GEDI-Data-Resources \n", "\n", "