 Is there any place on earth where we can hide and not be found? No. This series of satellites by USRO provides all weather earth observation. So now you can't go and hide anywhere and say that you can't be found. Do you want to know which satellite will catch you? Watch this video. First of all let us see about the RISAT series of satellites. See radar imaging satellite. This is only abbreviated as RISAT. So this radar imaging satellite is a series of Indian radar imaging reconnaissance satellites built by USRO. Now what is meant by radar imaging and reconnaissance? See radar imaging is a concept that uses radar technology to take pictures. It works the same like a flash camera. As we all know a flash camera sends out a pulse of light and records the light on the film that is reflected back at it through the camera lens. In the same way radar uses its own light to eliminate an area on the ground and take a snapshot picture. But note that small differences are here when compared to normal camera. See radar it uses an antenna and digital computer tapes to record its images. But in camera what did we see? We saw it uses components like lens and film. So this is one difference. See in a radar image we can see only the light that was reflected back towards the radar antenna. We cannot see the clear image but in camera we can see the clear image that was captured. Now this is about the radar imaging. Now coming to the term reconnaissance. See reconnaissance is the activity of getting information about an area for military purpose using soldiers, planes, drones, satellites etc. So RASAT uses these two concepts. One is radar imaging that uses its own light to eliminate an area on the ground and takes a snapshot picture and the other concept is reconnaissance. So it uses satellite to get information about an area. Now coming back know that the previous Indian observation satellites relied primarily on optical and spectral sensors which are hampered frequently by cloud cover. So this is one drawback of the previous Indian observation satellites. See there was no possibility of all weather surveillance because of this cloud cover. So to overcome this problem only the RASAT series of satellites were planned. And RASAT series are the first all weather earth observation satellites of ISRO. It provides all weather surveillance using synthetic aperture radar that relies on radar imaging technology. See initially RASAT-1 was planned to launch but after the 2008 Mumbai terrorist attacks India was in immediate need of surveillance capability. But at that time the indigenous technology that needed to develop the RASAT-1 was still on development. So with the help of Israeli technology in April 2009 ISRO launched RASAT-2 and this is the first of the RASAT series to reach the orbit. And this satellite enhanced India's capability for disaster management applications and also the country's surveillance capabilities. So what do we know from this we know that RASAT-2 is not an indigenous satellite. And then only in 2012 ISRO launched the RASAT-1 and this was India's first indigenous all weather radar imaging satellite. See the other satellites in the series include RASAT-2B, RASAT-2B-R1 and they were launched in the year 2019. And the RASAT-2, BR-2 and RASAT-1A they were launched in November 2020 and February 2020 respectively. Now these are some of the information regarding the RASAT program. Now coming to the applications of it, firstly this RASAT satellite series they are used for spot imaging. See the satellite will be used for high resolution spot imaging of locations of interest. So using this we can easily find out terrorist locations or wanted criminals location or even we can use it for wildlife protection. So this is one application. Secondly the remote sensing applications of the RASAT are used to monitor vegetation of a particular region and then in the field of agriculture they can be used to monitor the health of the crops and they can also be used in monitoring of forest, soil moisture, geological factors, coastal regions and oceans. So remote sensing is another application. And thirdly the RASAT provides tremendous support in the field of disaster management. See during the time of exigencies the high resolution and all weather imaging capabilities could be utilized for search and rescue. So this is another application and finally in the aspect of surveillance and security the all weather imaging capabilities could be utilized for border management and counter insurgency applications. Like I already said it helps us by providing views of terror camps, bunkers etc. See ISRO has said that on October 30th the RASAT two satellites had made an uncontrolled re-entry in the Indian Ocean and ISRO also highlighted that the initial designed life of the satellite was four years. But due to proper maintenance of orbit, mission planning and economical usage of fuel RASAT two provided very useful payload data for 13 years. Now that's all in this discussion we saw about radar imaging satellite series RASAT we saw about two concepts radar imaging and reconnaissance and after that we saw the satellites that were launched under the series and finally we ended our discussion by seeing some applications of the RASAT series. Now if you want to know more science related topics like this subscribe to Shankar A.A.'s Academy's YouTube channel or watch the daily news analysis of Shankar A.A.'s Academy. Thank you.