In this monthly feature, we span the globe to examine Our Changing Landscape with a time series of medium-resolution PlanetScope satellite imagery. The PlanetScope constellation dates back to 2016 and collects hundreds of millions of square kilometers of four and five-band 3-meter imagery daily! During March we focused (unsuccessfully) on flooding in one of Africa’s best-known cities, and for this edition of Our Changing Landscape we travel to the recent crisis in Texas with a view at the sudden and drastic weather change in Dallas which left the region crippled.

The PlanetScope Microsat Constellation

Click on the image above to see an animation of 3-meter natural color PlanetScope imagery collected over Dallas, Texas, USA on February 1, 16, 19 and 22, 2021. In this animation you can see how quickly the region changed from a snow-free late winter landscape – as is seen in the February 1^st image – to a snowy-icy mess in the images from the 16^th and the 19^th. And then as quick as this disaster struck the region, the snow and ice had melted away by the 22^nd. In the February 16^th image, you can even see snow and ice on the major roads that crisscross the Dallas metropolitan – presenting an additional barrier to timely emergency rescue operations. (Images Courtesy: © Planet 2021)

PlanetScope is a constellation of more than 150 microsats referred to individually as Doves. Each Dove is able to collect up to 20,000 square kilometers (sq km) per day of 3-meter (m) 4-band multispectral (i.e. blue, green, red and near-infrared [NIR]) imagery; and newly launched SuperDoves collect 5-band multispectral adding in valuable red-edge spectral data. Across the constellation, PlanetScope is archiving more than 200 million sq km of medium-resolution imagery a day, making it the go to source for daily imagery over most locations. This massive archive dates back to 2016, offering the most complete and continuous record of spatial data on the planet since the start of the constellation’s ongoing launch schedule. Collecting 3-meter multispectral imagery is the equivalent of ‘high-resolution’ multispectral data imaged by a 75-centimer (cm) satellite (as this satellite would feature 75-cm panchromatic and 3-m multispectral), making PlanetScope an extremely competitively priced option at just $1.80 per sq km. With well registered images and nearly daily collections of most locations, PlanetScope is the ideal imagery source for this current-events focused series, Our Changing Landscape.

Mid-February Snow and Ice Storm in Dallas, Texas

Located in north-east Texas about 60 miles (100 kilometers) from the Oklahoma border, Dallas is the ninth largest city in the United States and when combined with its near-neighbor Fort Worth it is the fifth largest. The city has a subtropical climate with hot and humid summers and mild winters, where snow is uncommon. During the month of February, Dallas has an average high temperature of 61 degrees Fahrenheit (16.1 degrees Celsius) and a low of just 41 degrees Fahrenheit (5 degrees Celsius). So you can imagine the crippling impacts of a severe winter snowstorm when Dallas recorded about 4 inches (10 centimeters) on Feb 14^th and then about 2 more inches (5 centimeters) on the 17^th. But that is only half of the story as the region was also rocked with about a ten of an inch of ice in subsequent storms as well as freezing cold temperatures that lasted more than a week. In fact, on February 16^th, Dallas recorded its second coldest temperature ever at some -2 degrees Fahrenheit (-19 degrees Celsius) where it was colder than Anchorage, Alaska that day.

This crippling snow and ice storm, as well as the record cold, had a devastating impact on Dallas and the whole of Texas in general. Over the week plus of freezing temperatures, millions of Texans lost power and/or were plagued with rolling blackouts. In Dallas, at the height of the outages, some 194,000 customers struggled through nights of freezing temperatures without power for heating and most of them without running water. And of course, these freezing temperatures, lack of running water and inability to access food, medicine and other life-saving devices killed at least 17 people in Dallas and this number is expected to climb as more investigations are completed. The devastation in Texas (and across the states in general) also crippled local economies and even led to a significant dip in the daily COVID-19 vaccine count. In fact, Apollo Mapping was not immune to impacts from the snow and ice storms as one of our key vendors for elevation data products has offices in Texas that were closed for nearly a week, hampering our ability to deliver these datasets in a timely fashion. Now it is time to turn to the 3-meter PlanetScope archive to get a sense of just how quickly and drastically these record storms impacted the Dallas region – our heart goes out to all those who lost their lives to this unforeseen and dire weather event.

If you would like to find out more about using 3-meter PlanetScope imagery for your academic studies, engineering projects or any landscape analysis, let us know at sales@apollomapping.com or (303) 993-3863.