Remote sensing is the science and technique of obtaining information about an object, area or occurrence through measurements made from a distance. Simply put, remote sensing is observing things from a distance and collecting information about them without actually touching them. The information is then recorded and stored. All remote sensing systems consist of parts that collect information, record and store it, and then process and analyze it.
There are many kinds of remote sensing. For example, our eyes act as sensors that see things in response to the light energy the objects reflect. This information is sent to our brains where it is recorded and analyzed in our brains. For example, every time we read we are remote sensing. Our eyes detect the light and dark places on the page. The image is sent to our brains where it is recorded, and then analyzed. Our brains interpret the black splotches as letter which form words and have meaning. Only then do we "see" what it is.
Human beings have at least five senses that serve as sensors. We have brains to record, store, analyze and interpret the information. We can see reflected light and feel heat, which represent only a very small portion of energy in the electromagnetic spectrum. When compared to other animals or to human technology, our remote sensing capabilities are very limited. Many insects and some birds have senses much more sensitive than ours, and some are able to see beyond the visible part of the spectrum and into the ultraviolet and infrared. To make up for our limitations, humans (mostly scientists) have developed special instruments to detect, record and analyze electromagnetic radiation.
One of the simplest is the camera. A camera takes light energy and records it chemically on film. The film is then processed and the image transferred to paper where we can look at it. We call this final form a photographic image. The chemicals on the film can be sensitive to visible light energy. This means it will record the same images a human eye can see. Camera film can also be chemically sensitive to the "invisible" infrared energy, and can record on the film images that the human eye cannot see.
Scientists have also created very complex detectors that can sense many different wavelengths in the electromagnetic spectrum. These sensitive instruments record the reflected energy as numbers or digits. This digital information is often recorded on magnetic tape, like in a tape recorder or video cassette.
Divide the class into four groups that will each focus on one sense: sight, touch, sound and smell. Have the members in each group work in pairs to take "blind walks" to isolate the sense they are investigating. One member of each pair should close their eyes (they are the "sensor"), while the other member of the pair (the "scientist" positioning the sensor) carefully leads them to the object(s) or area to be sensed. (The school parking lot is an ideal place with warm cars still popping and smelling hot.)
Each student should be taken with eyes closed to the parking lot, with care not to reveal where they are going. They must then use that one sense and record in their minds as much information as they can about the parking lot with that one sense only. The scientist may want to place the sensor in one place for the entire time or move it to different places. IMPORTANT: The sight sensors should be led eyes closed to the parking lot and placed in a particular spot where they can see the whole thing. They should then open their eyes for one minute only. They may not move around, nor turn their bodies or heads. They must sense what they can with their eyes only with their head still. The touch sensors may not touch anything, but the scientist may put their hands or face near warm or cold objects. The smell and sound sensors may be positioned by the scientists near points of interest.]
The partner will then guide them, eyes closed, back to the classroom. Once back in the classroom the sensor student should write down as much information as they can remember. The sensor then gives this information to the scientist who must compile it in such a way -- without using object names -- so that another scientist might be able to deduce what it is based on the properties the sensor sensed.