10.4. Using Geo2Grid to Create Animations

The advantage of Geostationary Satellites is the temporal resolution of the observations. Geo2Grid offers an easy interface for creating animations from Geo2Grid GeoTIFF files. The following example demonstrates how Geo2Grid software can be used to create an animation of files from a latitude/longitude subset of GOES-16 ABI CONUS GeoTIFF images located over the Southeastern United States.

Create a series of GOES-16 ABI GeoTIFF files from a time sequence of data. In the bash shell script example below, I use the ABI CONUS Band 1 files to search for all files we have available from 4 January 2019. The files for this day are all located in the same directory. I then create true and natural color images from all time periods that are available.

#!/bin/bash

# Set GEO2GRID environment variables

export GEO2GRID_HOME=/home/g2g/geo2grid_v_1_1
export PATH=$PATH:$GEO2GRID_HOME/bin

# Get input list of files/times based upon ABI Band 1 files

ls -1 /data/abi16/20190104/OR_ABI-L1b-RadC-M3C01_G16_s2019004*.nc > file_list.txt

sort_list=$(cat file_list.txt | sort)

# Make images for each time period available
for file in ${sort_list} ; do

        echo ${file}
        # get date/time for geo2grid file search
        datetime=`basename $file | cut -c27-38`
        echo "datetime :"$datetime

        # Cut out a box with lat/lon bounds of 23N, 105W to 37N 75W
        geo2grid.sh -r abi_l1b -w geotiff --ll-bbox -105 23 -75 37 --num-workers 8 -p true_color natural_color -f /data/abi16/20190104/*${datetime}*.nc

done

exit 0

This script created 120 GeoTIFF images for my time period 10:00 UTC through 20:00 UTC, with a time step of every 5 minutes.

To create a 120 image animation, I use the Geo2Grid utility script gtiff2mp4.sh.

gtiff2mp4.sh my_true_color_animation.mp4  *true_color*.tif

The script wraps the ffmpeg video software, and combines all of the *true_color*.tif files found in the directory into an animation based upon defaults that make the output animations most compatible with modern video players. The output frame rate is 24 frames per second. The images will automatically be resized if they are large in order to ensure a smooth animation. I chose an output filename of my_true_color_animation.mp4. The software can also create animations from input .png files.

The figure below is the last image in the 120 loop sequence. The output MP4 animation is available for viewing at this site.

Fig. 10.8 The last GOES-16 ABI image from the 120 frame loop created with data from 4 January 2019. The image observations are from 19:57 UTC.