The steps in the process were these. First, sunlight was reflected from the fire through the atmosphere to the spacecraft where it was optically captured and converted to a coded electrical signal. This signal was in turn converted to a radio signal that was transmitted back to Earth, received at Alice Springs and converted back to an electrical signal. The very long sequence of electrical signals that comprise this image was stored as numbers on a magnetic tape. I purchased a copy of that magnetic tape and, using a computer and other hardware, converted the electronically coded numbers into light signals that were focussed onto optical film. The result is the image you have just examined.
By using relatively simple technology we can in effect put ourselves into the Landsat spacecraft to obtain this remarkable view of the Earth.
This view is an awe inspiring panorama, the like of which is entirely unobtainable on Earth.
What is more, the image that we are analysing will never die.
What was happening on the ground in Kakadu National Park on the morning of September 2, 1986 is stored on magnetic tape in several locations. Forever into the future, this image can be recalled and re-analysed whenever and wherever anyone is interested.
With these thoughts in mind, what else can be interpreted from the wildfire image? What other information can be extracted?
With a little thought and no specialised knowledge, it is possible to infer other details of this wildfire and of the environmental conditions at 0930 hours AEST on September 2, 1986. For example, it is possible to determine which direction is North and then decide the direction as well as the speed of the prevailing wind on that morning. The second answer follows from the first. The first answer can be arrived at by recalling the time of Landsat overpass, then deducing where in the sky the sun will be. The location of the shadows of the smoke plumes is useful here.
