Space4SDG15: Life on land

Published by- Joy Agrawal on 29/07/2021

Land life has always been drastically affected since industrialisation at. Steady pace but now on a catastrophic level. Marine life has witnessed the problems a lot later than life on land. The basic problem has been pollution, desertification and deforestation. Increasing air and sound pollutions levels have lead to a decline in the population of aerial life on Earth. Animals in forests don’t have a home due to the extensive deforestation carried out. Poaching another major chunk in decline of animals. The forests serve as basins to draw rain towards land. They help reduce the carbon footprint that we emit. We are slashing our saviours, without forests no rains will happen and the some portion of our carbon emissions sucked in by the trees of also gone. All organisms are necessary in the cycle because it is essential to maintain ecological balance. We must have all studied the food chain and all of it is a cycle. So how can space technology help here?

Space technology can aid in monitoring land conditions and all. The foremost thing is monitoring the forest cover. This has been given importance because monitoring the deforestation done and the forest cover lost will help in law enforcement to keep a check on the timber and agro industries for illegal deforestation or deforestation above permitted limited. How is the forest cover gauged, this can simply be done utilising our good friend the SAR data. As discussed in pervious articles, the SAR data can give a lot of data points despite clouds and weather conditions irrespective of the time for it uses transmission and receiving technology. Due to the uneven general terrain of the forest, the millions of rays will be reflected at different angles and at different times, this created multiple data points which are then arranged into a point cloud where essentially all the points transmitted are plotted and then this is processed to get the map. Then algorithms are used especially machine learning to detect uneven terrain and based on the continuity and the population density of the trees, the pattern is detected. The main advantage of SAR over regular photography is that, some people use a clever technique of only cutting trees from the different regions so it doesn’t create a void in a single regions instead over multiple regions. Regular imagery can miss these data points but the SAR will plot all points.

There is something we haven’t discussed about yet with respect to space technology and that is GNSS i.e. Global Navigation Satellite System. Its commonly known as GPS or global positioning system. This technology is actually helpful in putting GPS tags on animals to keep a track of them. This can help in tracking the health of animals and also the location which can help in identifying poaching of animals. We all know what GNSS is and how it is used but very few know the actual working of this technology. Here is it,

A GPS Satellite sends out signals continuously in all directions 3 dimensionally... They send out a time stamp and the position of the satellite. Your phone receives these signals and calculates how much time did it take for the signal from the satellite to reach the phone and therefore using the formula for speed we can calculate the time, but there is certain ambiguity here, you may at that distance anywhere in a sphere, it is like you are a point and the distance between you and satellite in the radius, so the point can be anywhere on the surface area of the sphere. So the GNSS system uses what is known as satellite lock if there are a minimum of 4 satellite signals being received by the receiver then it is a lock and it uses the distance from the 4 satellites and there positions in the 3D frame to find the location of the receiver.

Now in our case this works by finding the location of the animal and transmitting the location for the forest department to take note of it.

This is exactly how poaching control is done through GPS tracking, if an animal is showing less of no activity than usual then after a prescribed amount of time it can be considered dead, and if there is movement to some place which has never been the place of movement for the animal then this can be considered as a smuggling route which can then be confirmed through other sources.

Finally, there is one of the most important points to be done and that is control and detection of forest fires. Satellite imagery can also be used to track ongoing bush fires and forest fires to locate new regions being affected using optical as well as temperature sensing of the area. Newer areas being affected with fires can be given immediate attention to avoid the spread of fire to new regions. We can compare the past heat maps of region under normal conditions with the latest one amid the fire to understand changes in temperature over newer regions. Secondly even SAR can be used because burning will reduce the height and amid the forest fire, the knowledge of brunt down areas and the wind direction can be used to predict further spread so that the situation can be prevented for happening.

As discussed above space technology can be very useful in the helping curb the side effects of extensive human population explosion and industrialisation.