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HS3 HIWRAP Radar Reflectivity Profile Quick View

Description

The Hurricane and Severe Storm Sentinel (HS3) airborne field campaign used the High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) instrument to collect wind and precipitation measurements.  This data recipe enables users to generate a time-height plot of the measured HS3 HIWRAP radar reflectivity through a Python plotting routine. The Python routine requires users to define the GHRC OPENDAP path to a data file and measured variable of interest.  This data recipe then plots the data to provide a quick visualization of radar reflectivity.  To run this Python routine, a pre-installed version of Python and additional Python packages are required. Advanced users may alter the code to plot other HS3 HIWRAP data variables.

Data Recipe Type
Data Visualization
Supporting Software Information
TYPE ACCESS
Python Script Open Source
 
This data recipe is available as a Python script.  To run the Python script, please install the following Python packages: matplotlib, NumPy, and Pydap.
 
Step 1
Follow the location link on this page to access the GHRC DAAC data-recipe folder on GitHub and obtain the HS3 HIWRAP Quick View Python Script: “HS3_HIWRAP_Quickview.py”.
 
You can preview the script by clicking the file name. To download, select the green “Clone or download” button located on the right side of the webpage to download the script as a zipped file or to open on your desktop. Save the file to a desired folder location on your computer.  You may also directly copy the script from the GitHub preview and paste in within your Python environment.
 
Step 2
Open the Python environment installed on your computer and make sure the required Python packages outlined in the “How to Use” section are installed. 
 
Navigate to the location on your computer where the data recipe Python file is saved and open the file within your Python environment.
 
Step 3
This Python script contains editable fields that can be used to plot the variables provided within each HS3 HIWRAP data file. This data recipe focuses on the radar reflectivity (ref) parameter.
 
A GHRC OPeNDAP link is used to pull in and plot variables within these data files. To access the GHRC OPeNDAP, a free NASA Earth Data user account is needed to access this page.  If you do not have an account, you will first need to create one.
 
 
Once your NASA Earthdata account has been created, you can access the GHRC OPeNDAP for the HS3 HIWRAP data files categorized by year here. Simply navigate to the desired year and day, then copy the name from the web page as shown below.
 
 
Step 4

Within the Python script, to change the default data file to the one you want to use, simply paste your file name in the "datafile" variable in the region highlighted below. Make sure to update the OPeNDAP URL path to reflect the year and day of the data file in the OPeNDAP path.

 

Step 5

Within the “Set Parameters” portion of the code, there are two variables for defining the final plot font sizes.  To change the font size of the plot labels, you may alter the “pltlbl_size” variable in the area highlighted.

To change the font for the rest of the plot (e.g. axis font, color bar etc.) change the font size within the matplotlib parameters highlighted below.

 

Step 6

Within the data file, the time field is defined in hours since the beginning of a given flight on a given date.  For the data file used in this data recipe, the start time is 00:00 UTC on October 17, 2014. To make this information more readable, the next portion of the code reformats the time field so that the time is shown in standard UTC time on the final plot.  You do not need to make an alterations to this section.

 

Step 7

Once the time is formatted, the array of values containing the radar reflectivity in dBZ and associated time and range information is split in half to generate two separate panel plots.

 

Step 8
The remaining code in this data recipe formats the plot.  
 
To change the color scale used, change the highlighted portion of the cmap variable shown below.  Additional color scale options may be accessed here.
 
 
This data recipe also provided the option to manually change the font size of the color bar labels. To do this, comment out the existing cbar.set_label and cbar2.set label parameters highlighted.
 
 
Then, un-comment the two parameter lines provided as shown below.
 
 
Step 9

To create the final plot, simply run the code and the generated plot shown below should appear.

Please note that this Python script may be reused and altered to plot additional HIWRAP data variables.  This plot has not undergone any quality control measures, so additional alternations are needed for scientific use.

 

Dataset Name Hurricane and Severe Storm Sentinel (HS3) High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP)
Platform Global Hawk UAV
Instrument High Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP)
Science Parameter Radar Reflectivity
Format NetCDF-4/CF
Data Information Data information

 

Variable Description Dimension Units Scale Factor
time UTC time 1D hours (since start of flight) none
range Range from radar 1D meters none
ref HIWRAP radar reflectivity 2D dBZ none

 

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