When Remote Sensing Satellites Were First Launched....
Did you know that the first photographs of the Earth’s surface were taken during the early Apollo missions as practice for mapping the Moon?
These early photographs provided the stimulus for launching the Landsat satellites in the 1970s - a program that provided the first civilian uses of satellite data - and is still going strong today. In today’s world of commercial satellites ringing the Earth, it seems almost quaint to remember that one of the arguments used most often against the Landsat program was that high-altitude aircraft could do the job just as well. In fact, the story of how the Landsat program was created and the battles to get it off the ground is fascinating!
Back in the 1960s and 1970s, scientists were familiar with data from weather satellites and the kinds of questions they could answer. But what else could be seen from space? And how useful was it?
So, when the first Landsat satellite was launched on 23rd July 1972, the biggest questions were about the type of sensors, how useful the data were and the kinds of applications that could use the data. That’s why the first satellite carried 2 sensors that would be used to monitor the Earth’s landmass - an RBV camera to capture images and an experimental multi-spectral scanning (MSS) sensor that scientists hoped would be useful but had no idea if it would be. And, in the fun and annoying way that science often works - scientists discovered that the experimental MSS sensor produced data that were much more useful and accurate than the RBV camera! So, while the RBV camera system was carried by the next 3 satellites in the Landsat program, the MSS data were what scientists focused on.
NASA asked a team of over 300 scientists from all over the world to discover different applications of the Landsat data to their fields. And the scientists found that satellite data could be used for all kinds of applications - identifying different crops from space so that governments could make better decisions about their agricultural sector, monitoring the behavior of cyclones and storm systems, mapping deforestation, exploring changes in how land was used by people around the world and even identifying unknown mountains in the Arctic and Antarctic.
The Landsat program continued adding more sensors over the years - with Landsat 7 having the most accurate and detailed data of all the satellites. The data were finally unlocked and offered for free in 2008 - and since then, we’ve seen an explosion of both commercial and scientific uses for the data. Fun fact - Google Earth uses Landsat data to visualize the planet!
Today, we have data from all kinds of sources - satellites, aircraft, drones, and submarines. All these come under the banner of remote sensing - that is, any data collected at a distance from the source. And they are equipped with a wide variety of sensors that help us collect different types of data at different resolutions and solve a range of problems. Together they help us understand different aspects of our planet - what happens on the surface, below ground, in the ocean, in the atmosphere, in forests, in crop fields - all kinds of things.
If you’re interested in learning more about remote sensing and how to access and analyze data from remote sensing, join us for our live workshop and online course this Sunday, June 14th from 11am to 12.30 pm Pacific Time. Click here to sign up!
