How to Access and Interpret AVHRR Data from NOAA CLASS: A Guide for Weather Satellite Analysis

The Advanced Very High Resolution Radiometer (AVHRR) is a sensor aboard several weather satellites that provides data for weather forecasting and climate monitoring. Data collected by AVHRR include measurements of sea surface temperature, vegetation health, cloud cover, and atmospheric temperature profiles. The National Oceanic and Atmospheric Administration (NOAA) provides access to AVHRR data through the Comprehensive Large Array-data Stewardship System (CLASS). This article discusses how to open AVHRR files downloaded from NOAA CLASS.

Step 1: Downloading AVHRR Data from NOAA CLASS

Before we can open AVHRR files, we need to download the data from NOAA CLASS. To do this, we must first create an account on the NOAA CLASS website. Once we have created an account, we can search for AVHRR data by specifying the date, time, satellite, and other parameters. Once we find the data we are interested in, we can add it to our shopping cart and download it as a zip file.

Step 2: Extracting the AVHRR data

Now that we have downloaded the AVHRR data from NOAA CLASS, we need to unzip the files. The zip file will contain several files, including a metadata file, a browse image, and one or more data files in HDF format. To unzip the files, we can right click on the zip file and select “Extract All”. This will create a new folder containing the unzipped files.

Step 3: Install HDFView

To open the AVHRR data files, we need to install HDFView, a free software tool for viewing and editing HDF data files. HDFView can be downloaded from the HDF Group website. Once we have downloaded and installed HDFView, we can open the program.

Step 4: Opening the AVHRR Data File in HDFView

To open the AVHRR data file in HDFView, we can go to File > Open and select the data file we want to open. The data file will have a .hdf extension. Once we have opened the file, we will see a list of datasets in the left pane. We can expand each data set to see the variables and attributes associated with it. We can also use the tools in HDFView to visualize the data, extract subsets of the data, and export the data to other file formats.

Conclusion

Opening AVHRR files downloaded from NOAA CLASS can be a daunting task, but by following the steps outlined in this article, we can make the process much easier. With the right tools and a little practice, we can access and interpret AVHRR data to gain insight into weather patterns and climate trends. By using AVHRR data, we can contribute to the understanding of our planet’s environment and take steps to mitigate the effects of climate change. Remember, the data provided by NOAA CLASS is a valuable resource that should be used responsibly and with care.

FAQs

1. What is AVHRR data?

AVHRR data is collected by sensors aboard weather satellites and includes measurements of sea surface temperature, vegetation health, cloud cover, and atmospheric temperature profiles.

2. How do I download AVHRR data from NOAA CLASS?

To download AVHRR data from NOAA CLASS, you need to create an account on the NOAA CLASS website, search for data by specifying the date, time, satellite, and other parameters, add it to your shopping cart, and download it as a zip file.

3. What is HDFView?

HDFView is a free software tool for viewing and editing HDF data files. It is used to open AVHRR data files downloaded from NOAA CLASS.

4. How do I open an AVHRR data file in HDFView?

To open an AVHRR data file in HDFView, you need to go to File > Open and select the data file you want to open. The data file will have a .hdf extension. Once you have opened the file, you will see a list of datasets in the left-hand panel.

5. What can I do with AVHRR data once I have opened it in HDFView?

Once you have opened AVHRR data in HDFView, you canuse the tools to visualize the data, extract subsets of data, and export the data to other file formats. You can also explore the variables and attributes associated with each dataset to gain insights into weather patterns and climate trends.

6. Are there any other software tools I can use to open AVHRR data files?

Yes, there are several other software tools that can be used to open AVHRR data files, such as Panoply, IDL, and MATLAB. However, HDFView is one of the most commonly used tools and is a good place to start if you are new to working with AVHRR data.

7. What are some best practices for working with AVHRR data?

Some best practices for working with AVHRR data include using appropriate software tools, carefully examining the metadata associated with the data, and being mindful of the limitations of the data. It is also important to acknowledge the sources of the data and to use the data in accordance with any licensing agreements or guidelines provided by the data providers.