Posted on April 2nd, 2024

30-cm Color WorldView-3/4 Image of the Month – The Afon (River) Dwyryd

Every time we look at WorldView-3 and WorldView-4 (WV3/4) imagery, we are blown away. And we hope you are equally impressed with the data! In March, we checked out and were intrigued by an image of the abandoned Six Flags amusement park in New Orleans. For this edition of the 30-cm Color WorldView-3/4 Image of the Month, we visit the Afon Dwyryd, a river in Gwynedd, Wales, that flows westward.

WorldView-3 launched in late 2014 and WorldView-4 launched in late 2016; taken together they are the most advanced satellite constellation the commercial marketplace has ever had access to. Here are a few of the features that really set these satellites apart from the competition:

This month’s 30-cm WorldView-3 image features the Afon Dwyryd, a river (afron means river in Welsh) which flows through a wide valley formed by glaciation and joins the River Glaslyn in Wales, UK. Both enter Porthmadog Bay and eventually drain to the sea into Tremadog Bay. Despite its connection to the sea, the river isn’t deep enough to accommodate sea-going ships. Before Porthmadog was created, slates quarried at Blaenau Ffestiniog were carried by small sailing vessels from quays on the Afon Dwyryd. They were taken to an anchoring spot close to Ynys Cyngar, near the bar at the mouth of the Glaslyn, where they were then transferred into larger sailing vessels before for continuing on their course. The sailors of these little barges were known locally as Philistines. In fact, before the quays were built on the Dwyryd, the Philistines beached their boats on the banks of the river. The slates reached the Dwyryd’s banks by pack horses (actually donkeys and ponies) from the quarries. Over the years, the quarry owners had to spend money to improve the pack horse routes. Locally, anglers love fishing the river and there are several places where kayakers will set their kayaks afloat. This 30-cm WorldView-4 image of the Afon Dwyryd was captured on May 3, 2017. The image has been processed by Apollo Mapping for improved perspective, clarity and colors. (Satellite Imagery © 2024 Maxar Technologies)
  • Improved Resolution
    • Higher resolution means you can see more detail in WV3/4 imagery.
    • Data collected at nadir will have 31-centimeter (cm) panchromatic, 1.24-meter (m) visible and near infrared, 3.7-m SWIR (WV3 only) and 30-m CAVIS (WV3 only) bands.
    • At 20 degrees off-nadir, the resolution is 34-cm panchromatic, 1.38-m visible and near infrared and 4.1-m shortwave infrared.
  • Additional Spectral Bands
    • If spectral analysis is part of your project, then no other satellite can match WV3 with its: 8 bands of visible and near-infrared data; and 8 shortwave infrared bands which are crucial for geological studies.
  • Better Positional Accuracy
    • With accuracies of 3.5-m CE90% or better (without ground control even!), WV3/4 has no rivals for its enhanced positional accuracy.
  • Daily Revisits
    • At 40 degrees latitude, WV3 is able to image every location daily with 1-meter or better resolution and then every 4.5 days at 34-cm resolution or better.
    • WV4 is no longer collecting new imagery.
  • Increased Collection Capacity
    • WV3/4 feature 13.1-km swath widths (at nadir) with the ability to collect up to 680,000 square kilometer (sq km) of high-resolution data per day per satellite (though WV4 is dead now).
    • Improved control movement gyros translate into larger maximum contiguous collection areas per pass, with up to ~7,500 sq km of mono imagery and ~3,000 sq km of stereo possible.

If you are interested in WorldView-3 and/or WorldView-4 imagery for your next project, please let us know by phone, 303-993-3863, or by email,

You can also find more WV3 samples and technical information on our website here and then WV4 samples and information can be found here.

This entry was posted in The Geospatial Times and tagged , , , Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

    The Geospatial Times Archive