What is Rapid Revisit and Why Does it Matter?

Rapid revisit is a qualitative term used in satellite monitoring to describe the ability of the system to make repeated image captures separated by short time intervals. This implies both that the constellation can respond at short notice to collect a target without waiting days for the satellites to pass overhead, and also that frequent collects can be made of a target over a given time of interest. 

What “rapid” precisely means can vary depending on who you ask, but here at Planet we define this as being able to take multiple images per day of the same location anywhere on Earth (something only our SkySat constellation can do today). This intra-day revisit capability has myriad benefits across diverse industries, from disaster relief to defense and intelligence to energy to business intelligence to global news events. 

Combined with other sources like the Automatic Identification System (AIS) data broadcast by ships, rapid revisit imagery can help track global commerce. These SkySat images show a tanker arriving at a Chinese oil terminal between 10:32 a.m. and 1:26 p.m. local time on May 21, 2019. © 2019, Planet Labs Inc. All Rights Reserved.

Many imaging satellites provide global coverage but are limited when it comes to revisit times, with some providing revisit rates as much as 5-10 days apart. It’s beneficial however to have the option of shorter intervals between images to really understand and characterize the rapid changes driven by human activity or unusual events. 

What makes Planet’s SkySat constellation so unique is that we are able to provide multiple observations a day, providing fresh and frequent data to better monitor change. Our satellites are positioned to image any point on Earth every day at 10:30am and 1:30pm. This is particularly useful in instances where cloud cover is an issue, increasing the likelihood that you’ll get a cloud-free image each day, or where specific shadow angles are important.

Six images captured between August 18, 2018 and August 21, 2018 show the movement of the Tupolev Tu-22M (Backfire) and Tupolev Tu-160 (Blackjack) bombers on the flight line of Engels Air Base, Russia. SkySat’s sub-daily rapid revisit capability allows “pattern of life” analysis for locations around the globe. © 2019, Planet Labs Inc. All Rights Reserved.

Of course, how rapid the revisit rate needs to be varies for different applications. For disaster monitoring, each minute and hour can bring about significant change—so a rapid revisit rate that provides imagery sub-daily or daily is incredibly valuable for those responding to the disaster. This is the case for defense and intelligence purposes as well, where early and frequent intelligence on strategic areas of interest or rapidly unfolding events is crucial to smart decision making and resource allocation. For the energy industry, the desired rapid revisit rate could be biweekly, like in the case of monitoring well pads, where construction happens over the course of several weeks.

Missouri River floodwaters arrived overnight in the town of Pacific Junction, Iowa. SkySat’s ability to collect imagery of selected locations at daily and higher frequency allows close to real-time monitoring of events as they unfold. © 2019, Planet Labs Inc. All Rights Reserved.

Planet’s unique constellation gives the options that meet each customer’s needs, providing the flexibility necessary to suit imaging needs no matter what your industry or business needs. 

Burning Man draws tens of thousands of visitors to Nevada’s Black Rock Desert annually. These SkySat images show the temporary city of 70,000 at the height of the 2018 festival: on August 28, morning and afternoon of August 29, and August 30. The sequence shows the playa’s famously variable weather—from bright sun to fierce dust storms. © 2019, Planet Labs Inc. All Rights Reserved.

To learn more about our SkySat offerings, please get in touch with our Sales team.