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Esri's ArcGIS is a geographic information system (GIS) for working with maps and geographic information.
It is used for: creating and using maps; compiling geographic data; analyzing mapped information;
sharing and discovering geographic information; using maps and geographic information in a range of applications;
and managing geographic information in a database.
The system provides an infrastructure for making maps and geographic information available throughout an organization,
across a community, and openly on the Web.
ArcGIS provides many products and solutions and we will focus on
ArcGIS for Desktop
.
A free 60-day trial version of ArcGIS for Desktop can be downloaded from
here
and
downloading the software requires Esri Global Account registration.
Please note that ArcGIS Desktop runs only on Microsoft Windows operating systems.
ArcGIS for Desktop is packaged as one big (~810MB) self extracting binary file. If you execute the downloaded file, it will extract all files at a location that you specify and start setup application after finishing extraction.
Upon successful installation, you can find the ArcMap application under a program file directory
such as C:\Program Files (x86)\ArcGIS\Desktop10.2\bin.
If you run the application, you'll get a screen as shown in Figure 1.
ArcGIS relies on GDAL library to read HDF data. Since GDAL can handle some NASA HDF-EOS files, you can open and visualize some NASA HDF-EOS data with ArcGIS on a map.
First, select WorldPlateCarree map under New Maps/Templates/Traditional Layouts/World as shown in Figure 2.
Then, you'll see a world map as shown in Figure 3.
Second, add an HDF-EOS data. In this example, we'll use an AIRS HDF-EOS2 Grid data, which you can download here. Since ArcGIS cannot handle .he2 file extension (.he5 for HDF-EOS5), you must rename the extension of HDF-EOS2 file to .hdf (.h5 for HDF-EOS5) if the file has .he2 extension. To load the sample file, select File > Add Data > Add Data as shown in Figure 4.
The above menu item selection will pop up a new dialog box as shown in Figure 5.
Click the Look in: drop-down selection box to select the folder that has the downloaded HDF-EOS2 file.
If you don't see the folder that has the downloaded file
under the Look in: drop-down selection box in the dialog box,
please click the Connect To Folder icon
in the dialog box and select the folder where you saved the HDF-EOS2 file.
The dialog box will list all types of files that ArcMap can handle in the folder.
After you select the AIRS.2002.08.01.L3.RetStd_H031.v4.0.21.0.G06104133732.hdf file,
press the Add button.
Then, you'll get a list of datasets that you can plot as shown in Figure 6. You can scroll down the list to pick a dataset of your interest. Please select only a 2-D dataset because ArcMap will treat any 3-D dataset as RGB band composite dataset, which is wrong because the 3rd dimension in AIRS has a different physical meaning. In this example, we will pick the subdataset 10 that has description [180x360] SurfAirTemp_A ascending (32-bit floating-point).
Then, click OK button and you will get a new warning dialog box as shown in Figure 7. You can ignore this message and press Close button.
Finally, you will see the data on top of the world map as shown in Figure 8.
If you want to change the color scheme, click on the grey color bar in the Table of Contents window on the left side of the map. You can also adjust labels and texts by double clicking them. To capture and export your final map, use the File > Export Map menu item. The Figure 9 below demonstrates the exported map in PNG format with color and text adjustment. Please click Help menu item for more details on how to customize your final map.
The method of directly accessing HDF data in the previous section doesn't work with some HDF-EOS files due to the geo-referencing issues. ArcMap will either fail to draw data on a map or plot the data at the wrong location. For example, if you apply the direct access method on OMI-Aura_L2-OMCLDO2_2009m1001t0941-o27729_v003-2009m1001t155925.h5 file, you will get an image as shown in Figure 10 below.
If you compare the Figure 10 above with Figure 11 below, you'll immediately notice that ArcMap plotted the data at the wrong location by examining south pole and greenland location.
If you have an issue with your NASA data as described in the previous section, there are other ways to visualize NASA data. In this section, we will explain 3 different ways of accessing HDF data with ArcGIS.
If the data is an HDF-EOS2 file, you can use HEG tool and convert the data into GeoTIFF. ArcGIS supports GeoTIFF format so it is very easy to visualize the converted GeoTIFF file. Simply use the File > Add Data > Add Data command as shown in Figure 4 above and you will see an image appear on the map almost right away.
One drawback of HEG tool is that it cannot support all HDF-EOS2 products, not to mention HDF4, HDF5, and HDF-EOS5. If your NASA data falls outside the HEG's supported product list, another solution is to convert HDF to NetCDF and then visualize the converted NetCDF data. You can convert HDF-EOS2/HDF4 to NetCDF through either HDF4 OPeNDAP Handler or H4CF Conversion Toolkit. You can convert HDF5 to NetCDF through HDF5 OPeNDAP Handler.
If you want to know how to get NetCDF through HDF4/HDF5 OPeNDAP handlers,
please refer to
How to Obtain Data in NetCDF Format via OPeNDAP
from GES DISC Services Cookbook website.
If you want to get NetCDF through H4CF Conversion Toolkit,
please read
How to Use the HDF4-to-NetCDF Conversion Tool.
Please note that the H4CF Conversion Tool is for only HDF-EOS2/HDF4 files and in beta version.
Once you converted your HDF into NetCDF successfully, please follow the steps in
How to Import Satellite Swath Data in NetCDF Format into ArcGIS
or
How to Import Gridded Data in NetCDF Format into ArcGIS
.
The Figure 12 below shows the plot of
NetCDF file that was converted from
our OPeNDAP demo server.
Please note that we used Feature to Raster tool in To Raster box
instead of Natural Neighbor tool in Spatial Analyst Tools > Interpolation box,
which is discussed in the
How to Import Satellite Swath Data in NetCDF Format into ArcGIS
document.
We could not get the desired plot for the OMI example using the interpolation tool.
It is possible that OPeNDAP service doesn't provide Get as NetCDF service.
In addition, Get as NetCDF service may fail to generate the correct NetCDF file for various reasons.
In such cases, one solution is to convert OPeNDAP data to NetCDF through ArcMap.
This is possible through a separate download and installation of Multidimension Supplemental Tools
available from ArcGIS Resources.
Please visit
here
for more information.
The Figure 13 below confirms that the plot of NetCDF file
that was created by OPeNDAP to NetCDF tool in Multidimension Supplemental Tools
is the same as Figure 12 above.
The tool allows subsetting and downloading individual dataset like OPeNDAP web form does.
