The h5py module daniel kahn science systems and applications, inc. Since hdfeos2 and hdfeos5 are built on hdf4 and hdf5, this library can also be used to access hdfeos data fields. Substituting hdf5 tools with pythonh5py scripts daniel kahn science systems and applications inc. A nasa earthdata login account is required to download the data used in this tutorial. Goddards technology, expertise, and facilities are a national asset that can be leveraged to develop new products and processes that benefit the united states.
Binary executables are available for windows windows 7 or later and mac os x yosemite or later at the project page listed below. It contains ncl, matlab, idl and python example scripts and the associated images. The output geotiff file is ingestible into commonly used gis applications. Python client library that abstracts cmr api calls for search, ingest, update, and deletion of collections and granules. Download data directly or order data to be optionally post processed andor staged for download.
Simple example about how to read a modis hdf file using python and the pyhdf library note. In this tutorial, you will use python to define the coordinate reference system. Introduction to the hdf4 data format earth data science earth lab. Genrate grid information file from modis hdfeos data stack. Hdf compass is written in python, but ships as a native application on windows, os x, and linux, by using pyinstaller to package the app. Download and unpack then cd into that directory and run. R a statistical computing library that supports hdf4 and hdf5. Hdf is the prescribed format for standard data products that are derived from eos missions.
Nco netcdf operators the netcdf operators, or nco, are a suite of file operators which facilitate manipulation and analys. Some aster hdf eos products lack any georeferencing. What youre seeing is just the api that gdal provides to access an hdf4 dataset and its subdatasets. Converting from hdf to ascii format national snow and. You will also need to download a free hdf viewer from the hdf group website. Hdf files are hierarchical and self describing the metadata is contained within the data. Introduction to the hdf4 data format earth data science. To use these, click download source to download or copy and paste the code into a file with an extension reflecting the programming language. Hdfeos tools and information center help was so nice to provide a script to deal with. Cloudnative, service based access to hdf data python docker aws hdf5 asyncio dataanalysis multidimensional python apache2. Download follow the directions below to download and install heg standalone v2. Example programs of how to use hdf5 are provided below. Lastly, open a terminal or shell and execute the file. It supports hdfeos and landsat data, as well as spot data.
The hdf group is a notforprofit corporation with the mission of sustaining the hdf technologies and supporting hdf user communities worldwide with productionquality software and services. This module can read and write files in both the new netcdf 4 and the old netcdf 3 format, and can create files that are readable by hdf5 clients. If youre a docker user, please try our docker images of anaconda through docker hub that include all the required python modules e. Download anaconda 32bit python and install it at the default location c. We illustrate the use of ncdump to extract the metadata information from the hdf file header. Gdal is used to read some hdfeos grid files both version 2 and 5. If you need support for reading hdfeos 5 files, then you will need to download and install the following packages. Yet, its powerful enough to do almost anything you can do from hdf5 c. These benefits include increasing the nations competitiveness, improving the balance of trade, and enriching the lives of the citizenry.
The szip option is not widely used, and may be omitted for simplicity. Open and use modis data in hdf4 format in open source python. I first heard of hdf during the data format wars of the 1990s. How to read a modis hdf4 file using python and pyhdf. The moderate resolution imaging spectroradiometer, modis, can see the earth in true color as it appears from the satellite terra. The hdf group ensuring longterm access and usability of. Since hdf5 is the current and most supported hdf format, it may be easiest to first convert hdfeos files to hdf5 files using a conversion tool. Read, map and extract modis aerosol data using python scripts. Application for working with hdfeos files downloads.
It also measures an unprecedented number of parameters related to global change including ocean plant life, cloud properties, atmospheric particulates aerosols and land surface change. In each case, the file has one or more hdfeos object grid, swath, point and corresponding structmetadata. In addition to the standard conversion of hdfeos objects, the experimental program identifies and converts noneos objects in an eos dataset, creating a more complete hdfeos5 file. Hdfeos hierarchical data format earth observing system is a selfdescribing file format for transfer of various types of data between different machines based upon hdf. Fedora 20 the fedora 20 netcdf rpm is built with hdf4 support, so therefore netcdf4python can read hdf4 files out of the box, and the gdal rpm includes support for hdfeos, so for python2, everything just works. In conclusion, this experiment shows that the h4toh5 library provides a toolkit to more easily construct conversion utilities for nasa hdfeos files. Because the data are hierarchical, you will have to loop through the main dataset and the subdatasets nested within the main dataset to access the reflectance data the bands and the qa layers. Because this software was developed under a nasa contract and was intended for the use of eos instrument teams and science investigators, access to download was password protected. The fedora 20 netcdf rpm is built with hdf4 support, so therefore netcdf4python can read hdf4 files out of the box, and the gdal rpm includes support for hdfeos, so for python2. If your os distribution already contains prebuilt hdf library you can use one from the distribution. The hdf group is a notforprofit corporation with the mission of sustaining the hdf technologies and supporting hdf user communities worldwide with productionquality software and. Click on a tool title for the detailed description and download information of that tool available through nasa data centers. The pythonhdf4 package wraps the functionality of the ncsa hdf version 4 library inside a python oop framework.
Hello everyone, is there any python or matlab code for conversion of nasa smap hdf5 l3l4 products to geotiff or netcdf formats. The sd scientific dataset, vs vdata and v vgroup apis are currently implemented. Gdal is a translator library for raster geospatial data formats such as hdf4 and hdf5. If using a hdf5 files, h5py or pytables can be used to access the data in the file. Chapter 12 modis hdf4 remote sensing data in python. Hdf4eos, the format adapted from hdf4, is the currently used format for. Im trying to read modis 17 data files into r, manipulate them cropping etc. Makes possible the management of extremely large and complex data collections. To download automatically a modis granule on your local repertory, see download modis granule hdf files from lads using python note 1.
These battles centered on the selection of a format for the emerging nasa earth observing system archives, and there were a number of contenders. While the transition to hdf5 has occurred for many remote sensing products, hdf4 is still the primary data format that is adapted for modis data products published. Be sure the unix execute permissions are set for the file. Start by launching in a console window the ipython interpreter.
Not only is the format itself platformindependent, but nearly every analysis platform in common use can read hdf5. The heosls utility 2 was used to summarize the objects in the file table 1, left column. Pomegranate is an open source python application that implements w10nsci api. How do i get the sdp toolkit, hdfeos, mtd toolkit and. The hdfeos to geotiff conversion tool heg is a tool developed to allow a user to reformat, reproject and perform stitchingmosaicing and subsetting operations on hdfeos objects. Working with daily nasa viirs surface reflectance data lp daac. Hdf4 is an older hierarchical data format as compared to hdf5, which is the latest version promoted by the hdf group, the publisher of the libraries and standards for these formats. Hdfview a visual tool for browsing and editing hdf4 and hdf5 files.
Once you have the hdfeos 5 source code, you can build and install it with. Hdf won that battle in the end because of the inherent flexibility of the format and the tools for reading and writing it. This page contains some suggestions and links to get you started reading and using omi level 2 data. The sdp toolkit, hdfeos and related tools are available via our download site observer. In the previous code, we have seen a way of neatly creating the filenames required by gdal to access the independent datasets. An enormous amount of effort has gone into the hdf ecosystem over the past decade.
This is an extension of standard hdf5, mainly standardising how metadata is stored in the files, and the location of certain groups within a file. Starting to use python to work with geospatial data gdal. It can also reformats and reproject some smap, viirs and srtm products. These are hdfeos files, specified by nasa and based on the hdf4 specification. Netcdf files can also be read and modified with pythonhdf4. For hdfeos specific examples, see the examples of how to access and visualize nasa hdfeos files using idl, matlab, and ncl on the hdfeos tools and information center page examples.
Once you can run anaconda successfully, use conda install h5py from anacondas python shell. Because of a concerted effort between the hdf group, standards bodies, and analysis software vendors, hdf5 is one of the best technologies on the planet for sharing numerical data. Read, map and extract modis aerosol data using python. If using hdf4 data with python, check these resources.
1079 777 1230 860 362 903 1075 434 1330 1152 284 499 509 1052 1241 1466 1011 940 782 665 1127 365 703 439 791 1249 1382 680 1341