This month’s 30-cm WorldView-3/4 image features Alcatraz Island, a former maximum-security, minimum-privilege federal prison located 1.25 miles offshore from San Francisco, California that in 1972 became designated as an island within the Golden Gate National Recreation Area per an act of Congress. The island opened to the public in the fall of 1973 and has become one of the most popular Park Service sites with more than one million visitors from around the world visiting each year. There’s even the option to visit virtually. In 1850, a presidential order set aside Alcatraz Island for use as a United States military reservation. The California Gold Rush, the resulting boom in the growth of San Francisco and the need to protect San Francisco Bay led the U.S. Army to build a Citadel, or fortress, at the top of the island in the early 1850s. By the late 1850s, the first military prisoners were being housed on the island. From 1909 through 1911, the military prisoners on Alcatraz built the new prison, which was designated the Pacific Branch, U.S. Disciplinary Barracks for the U.S. Army. It was this prison building that later became famous as “The Rock.” The U.S. Army used the island for more than 80 years – from 1850 until 1933, when the island was transferred to the U.S. Department of Justice for use by the Federal Bureau of Prisons. The federal government had decided to open a maximum-security, minimum-privilege penitentiary to deal with the most incorrigible inmates in federal prisons, and to show the law-abiding public that the federal government was serious about stopping the rampant crime of the 1920s and 1930s. During the 29 years (1934-1963) that the federal prison operated, 36 men (including two who tried to escape twice) were involved in 14 separate escape attempts. Of these, 23 were caught, 6 were shot and killed during their escape and 2 drowned. Two of the men who were caught were later executed in the gas chamber at the California State Prison at San Quentin for their role in the death of a correctional officer during the famous May 2-4, 1946, “Battle of Alcatraz” escape attempt. On March 21, 1963, USP Alcatraz closed after 29 years of operation because the institution was too expensive to continue operating. An estimated $3-5 million was needed just for restoration and maintenance work to keep the prison open. Alcatraz also has been home to several art installations. This 30-cm WorldView-3 image of Alcatraz was captured on November 2, 2018. The image has been processed by Apollo Mapping for improved perspective, clarity and colors. (Satellite Imagery © 2024 Maxar Technologies)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 June, we couldn’t pull our eyes away from the Dun Briste Sea Stack in County Mayo, Ireland. For this edition of the 30-cm Color WorldView-3/4 Image of the Month, we visit Alcatraz Island which is offshore of San Francisco, California, a former maximum-security, minimum-privilege penitentiary designated to house the most taxing prison inmates such as Al Capone, George “Machine-Gun” Kelly, Alvin Karpis (the first “Public Enemy #1”), and Arthur “Doc” Barker.
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:
- 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, sales@apollomapping.com.
You can also find more WV3 samples and technical information on our website here and then WV4 samples and information can be found here.
Copyright © 2025 All Rights Reserved - 
Leave a Reply