Let’s take a closer look at the misconceptions and myths surrounding Earth Observation or satellite imagery. Earth Observation or satellite imagery has become an essential tool in the geospatial industry, providing valuable insights into the Earth's surface, atmosphere, and human activities. However, there are some misconceptions about this technology that need to be addressed.
Here are top 10 myths people hold about EO:
Satellite imagery is just for government spies or military organizations.
It's not just intelligence entities and soldiers playing spy games up there anymore! Satellite imagery is used by a wide range of organizations, including private enterprises, academic institutions, and non-governmental organizations. Today, integrating satellite imagery into enterprise-grade data systems entails a combination of cloud-based computing, APIs, machine learning, and geospatial data management technologies. By leveraging these tools, organizations can unlock the full potential of satellite imagery for a range of applications, from disaster response to environmental monitoring to supply chain management.
Satellite imagery is expensive and difficult to access.
Sure, some high-resolution satellite imagery sources can be pricier than others, but there are many sources of free or low-cost imagery that are available to the public. It's like the buffet of geospatial data - there's something for everyone and with recent advancements in technology, accessing and analyzing satellite imagery has never been easier. For those who are unsure about what imagery is best suited for their needs or who leverage several sources of data, their best option is to leverage a data agnostic platform like that of Astræa to avoid paying subscription fees to and managing lengthy contracts for each individual data provider. Rather, with data aggregation platforms, you can leverage a multitude of data sources from one API, under one contract, and with one statement.
Satellite imagery is always accurate and reliable.
Unfortunately, like most things, satellite imagery isn’t perfect all the time, but at least it’s objective information. Just like humans, satellite imagery has limitations, such as cloud cover or atmospheric interference, which can affect the quality of the data. Unlike with humans, however, mitigating systemic bias can be relatively straightforward. Just make sure you analyze the data thoroughly before making any conclusions or get expert guidance to ensure your insights are accurate.
Satellite imagery only shows pretty pictures built for visual inspection.
While satellite imagery can be stunning and you should definitely swipe right, it's more than just a pretty face. Not only can satellite imagery provide compelling visual information, but it can also produce a wealth of other data, such as temperature, humidity, vegetation indices, and atmospheric gasses. It's not just a picture, it's a whole package.
Satellite imagery is only useful for monitoring large-scale changes.
Many satellite imaging platforms are excellent at detecting small changes, with high spatial resolution and frequent revisits. If implemented correctly with a process called “tip-and-cue”, satellite imagery can even serve as a sort of ‘Ring Camera’ for your site. For example, Planet Labs' Dove and SkySat constellations offer spatial resolutions ranging from 5 m to 50 centimeters per pixel, with revisit rates as often as every day. This level of detail allows for monitoring changes as small as a single car at a facility. Similarly, Maxar's WorldView-4 satellite, which offers a spatial resolution of 31 centimeters per pixel and a revisit rate of a little over a day, allows for monitoring changes in urban areas, construction sites, and even individual trees. Clients of Astræa can do their large scale monitoring with archive data from something like Sentinel 2, which has lower resolution but is constantly taking images of the Earth, apply AI/ML on top to detect changes, and then trigger an image request or “image tasking” once something is detected to asses the small scale changes.
Satellite imagery is only useful for monitoring natural phenomena.
Sure, satellite imagery is great for monitoring natural phenomena, but it's also useful for planning and monitoring human activities. From planning infrastructure development like a new solar facility to monitoring deforestation and mining, satellite imagery can help keep us on track and accountable. It's like a consultant to help you optimize your next investment and a watchdog that keeps tabs on bad actors and verifies reports without needing boots-on-the-ground.
Satellite imagery is only useful for monitoring changes over long periods of time.
Not quite. Satellite imagery can be used to monitor changes over a range of time scales, from days to years. With a process called tasking, we can even request images to track the development of rapidly evolving events like wildfires, floods, or deforestation in near real-time. Today with the increasing popularity of SAR data and night-imaging, one could even investigate the difference between an image taken during the day and a SAR image taken that same night.
Satellite imagery is only useful for monitoring land surface changes.
Incorrect. While satellite imagery is undoubtedly great for tracking land use and land cover change, it can also be used to monitor changes in and on water, as well as in the atmosphere.For instance, some satellite platforms are highly effective for monitoring changes in the atmosphere, such as air pollution, ozone depletion, and weather patterns. Some examples of these platforms include Sentinel-5P, which provides data on atmospheric pollutants, and NASA's Aqua satellite, which measures parameters like sea surface temperature, cloud cover, and aerosol concentration. Satellite imagery can also be used to monitor changes in and on water, such as monitoring the spread of harmful algal blooms, detecting oil spills, and tracking water quality. For instance, Umbra's Synthetic Aperture Radar (SAR) data is great for monitoring marine traffic and detecting oil spills, while Maxar's WorldView data has been used to map coastal erosion and detect harmful algal blooms.
With satellite imagery, you can look at any location at any time.
This is a tough one. Admittedly, some satellite tech marketers have taken liberties in describing, or even obfuscating, what revisit rates are. Revisit rates refer to how often a satellite passes over a particular area of the Earth. While some satellites may have a high revisit rate of just a few hours, others may take several days or even weeks to revisit the same area. It’s important to note that just because a satellite passes over an area and CAN take an image, it doesn’t mean that there will be availability (i.e, too much demand on the satellite) nor does it guarantee that the image that is taken will be of sufficient quality, although this can be mitigated by specifying low cloud cover acceptance and your preferred incidence angle. Revisit rate is particularly important for applications that require near-real-time monitoring or frequent updates. Depending on the specific use case, it may be necessary to use multiple satellite sources to ensure sufficient coverage and revisit rates.
All satellite imagery is created equal.
Satellite imagery is a tool that can be leveraged to gain insights for your business. Like any tool, there are specific use cases where it makes sense to use one tool over another. A good mechanic would never recommend tightening a bolt with a hammer. It’s important to know that different satellites have different coverage and resolutions which helps determine which use cases it aligns best with. Even more, some tools are well standardized while manufacturers may not standardize their tools very well. In the EO space, there has been a recent push for standardized formats like STAC. This standardization helps you analyze the data at scale and therefore is an important aspect to evaluate when choosing your imagery.
Now that we've cleared up these misconceptions, let's talk about the importance of transparency within the geospatial industry. It's crucial that we are open about the limitations of satellite imagery, and communicate clearly and honestly with our clients and partners. We also need to analyze data at scale to ensure that we are making informed decisions based on accurate and up-to-date information. As purveyors and analysts of EO data, we at Astræa recognize how important it is to consider the revisit of satellites and what the coverage is to set realistic expectations with those less familiar with satellite imagery and we also advocate for the standardization of data formats in order to future-proof scalable, analytical solutions. So the next time you’re evaluating what new data pipelines could level-up your business processes, consider the power of satellite imagery, how much the EO market has changed, and where platforms like Astræa’s can give you a leg up!
