Validating remote sensing observations

Adventure movies make it seem like satellites can see everything from space, but is this fact or fiction?

Remote sensing satellites provide us with lots of information, but as demonstrated by this image, they don’t tell us everything. We can see roofs, sunshades and trees – from which we can make inferences about these structures – but we can’t tell for certain what’s under the structures and what functions they may serve. For real proof, we need direct on-the-ground observations!

This activity helps students discover the benefits of using satellite and ground-based observations to build a more accurate picture (or model) of what is being observed. Careful teacher questioning can aid students in transferring this experience to more-abstract satellite measurement scenarios.

In this activity, students use satellite images of their school or other well-known locations to practise the science capability ‘Gather and interpret data’. Comparing what they observe from space with what they directly observe on the ground enables students to explore the concepts of data validation and ground-truthing. Validation and ground-truthing are vital for ensuring the accuracy of the information we get from satellites.

• observe a satellite image and describe what they see
• make inferences about what is in the image (predictions about what they cannot directly observe)
• observe the same location at ground level and describe what they see
• make comparisons between the observations to ensure a match with the satellite image/location and observed objects
• discuss whether their inferences are correct
• discuss how both sets of observations provide more-accurate detail when used together
• discuss the importance of validating and ground-truthing data provided by satellites. (optional).

The activity Interpreting observations from satellite images has strategies for helping students interpret images. It may be helpful for students to learn some of the strategies prior to doing this activity.

Download the Word file (see link below).