Tag Archives: Satellite

On the dark side of the Moon

Were we ever lost in the moon while looking up high in the skies? You might remember, maybe you’ve dreamt about touching the moon or maybe walking towards it with a ladder. They might sound silly, but these facts used to fantasize us when we were young and heard such stories from our parents and grandparents too. We see the moon is round, and then it changes shape to crescent and diminishes one day. Do you know there are eight phases of the moon? They are :

  • new moon
  • waxing crescent
  • first quarter
  • waxing gibbous
  • full moon
  • waning gibbous
  • third quarter
  • waning crescent.
The phases of the moon in a single frame.

We know only one moon, but there are 219 in total in our solar system. Our planet earth has one, Mercury and Venus even have a single one, don’t they feel lonely, you can comment down. You may know the Venus does appear in the sky, so does the Mercury, try finding them next time. The other moons with the distribution as Phobos and Deimos of the Mars planet, 14 moons of the Neptune, 27 satellites of the Uranus, 79 moons of the Jupiter planet. The most leading number of moons is bound to Saturn, with 82 moons discovered till now. Moon, also a natural satellite, still can face a lunar eclipse.

We, humans, have put the first foot on the moon in the year 1969. Well, the moon is lighter being almost one-fourth than Earth and by 80 times with its diameter of 3476 kilometres. Can we see the entire moon surface, even during a supermoon? It does come a little bit close, but there is the other unknown side to discover. Recently, findings say that there are a minute number of radioactive elements on the near sides. There is around 31 percent dark region present on the near side. Let us know more about these sides. Mare, the dark zone, is usually at a lower elevation and typically flat. You may also notice the dark spot; those spots known as craters traditionally formed by the impact of a meteor attack. NASA also bought some rocks collected during Apollo missions.

An astronaut on the moon surface.

The worst thing among this situation was that the US, in the earlier 1950s, planned to destroy the moon using bombs. As in a book by John Greenwald, Jr, with the title called “Secrets from the Black Vault,” where it gets mentioned. It was due to the Soviet Union accomplished several missions and feared that they might dominate it. But luckily, the US reached the moon first, and such plans vanished out somewhere, and hopefully, someone didn’t talk about the topic.

Coming back, KREEP, a new rock found, is named before the initials of potassium (K), rare-earth elements, and phosphorous on the moon’s surface. The near side has regions with items like Uranium, Thorium which is rarely present on the other sides of the moon. These will help to know about the formation, and it’s earlier existence.

Well, even the moon, as we see, is not round in nature, but it’s an oblate spheroid. There are more things to discover, let’s us keep for the next time.


Starlink: Connecting People to Faster Data

Among the 4.57 billion internet users and growing, you are also a part of it, currently reading this post. Half of the total users are in Asia, where the youth is consuming most of the data. Most of them are creating an online presence by spending almost 6.5 hours a day on average. You might even think to ask a question to yourself, who owns the internet? The answer is no one. You are also a part of the internet, and you own it on your devices. You watch videos on YouTube, Netflix, chat with your friends, share posts on Instagram, share your opinion on Reddit, etc. It all started in the 1960s with the project known as ARPANET, originally started being a four-node network.

Internet: Where all the ideas originate.

The average internet speed around the globe is around 33 Mbps on Mobile, where South Korea tops the chart with a whopping 100 Mbps. On the other hand, fixed connections have a much higher number at 76 Mbps, with Singapore on the top of the list with 205 Mbps. You may not be experiencing the speed. In most cases, surfing the web, listening to songs like other users, is a priority. But the time has ended up to be a power user. Several opportunities are helping people to connect to the internet for the first time. Facebook, in 2013 launched a service known as Free Basics powered by Internet.org, which was a massive success, but some problems do arise. China banned Facebook since 2009, so no opportunities for them, India refused the offer due to net neutrality. Google’s initiative Project Loon, the balloons in the stratosphere, helped to connect around 200 thousand people in 2017 during Hurricane Maria that emerged in Puerto Rico.

A bunch of cubicles where the company connects to its employees through the network.

Now, a visionary man with fulfilling all his dreams is all geared up with the project called the Starlink. Elon Musk, the owner of SpaceX in 2015, presented his idea to the world how satellite communication can help us to get stable and faster internet connections. Five hundred forty satellites launched in orbit as of June 13, 2020. There are more launches in the future to make it the largest constellation consisting of 12 thousand satellites. The Russian Sputnik I was the first satellite to make its journey to space. Currently, there are more than 8 thousand satellites, out of which only 2, 218 are functional.

A switch used to connect several devices to a network

The problem is that the future can have issues like a traffic jam in orbit, yes, along with the space debris of non-functional parts of the older satellite. An incident on September 2, 2019, where ESA changed Earth observatory satellite from its usual path as Musk refused to change the same for Starlink. So this created some disagreement with the organizations. Six satellites have failed to add up to 20 thousand space debris, which is currently under strict observance.

A space rocket launch

A positive fact about the project is that to reach internet connectivity to the remotest area in the world. Do you know that the world fastest internet speed recorded recently peaked at 44.2 terabytes, which can download a thousand high definition movies just in a second? Starlink is aiming to provide speed in gigabits with low latency, and now it is inviting you to test the network. You can be a part of this.

“Satellites And Their Outweighing Assistance”.

The era which we see around is a total definition of how technology and science have made our life’s more comfortable and entertaining. We use technology in everything we admire to work on, be it our smartphones, vehicles ,cooking and many more. Our life is incomplete without these applications and thus are an important part of our day today activities. But these technologies are not only limited to this planet only. We have been able to accomplish the goal to reach the space with all the research work and various new ideas to develop the required technologies for them. The journey to space started with the launch of a satellite to it and till date it’s no looking back. We have sent a number of satellites to space irrespective of their size, rockets and even human beings. These surely have helped human in many way out. Satellites have been a part of our life for more than 5-6 decades and helped humans depending up on their needs. 

So the first question which comes to the mind of any individual is “What really is a satellite and how is it able to perform different activities”. We have been using satellites in anything we use today. Be it for watching television, weather reports, calling, GPS,Defence and many more. We are surrounded by technologies which do work with the help of these satellites and make our life more and more simple. So these satellites are objects which orbit our earth by remaining in its orbit. These are usually artificial satellites as these are man made, while the moon being our only natural satellite which do orbit our earth. The size of these orbits depends on the type of function they are meant for. These could be as small as mobile in your hand and could be as big as any vehicle or more. 

So “How these satellites work and get power from”. It’s difficult for us to charge these satellites regularly by bringing them back and also very costly. So these use the solar energy as power source for their functioning. Solar panels are usually attached on  the sides of these satellites, which trap the solar radiation and thus generate power. These usually consist of a transmitter in between which transmits the signal which they receive. These can also be controlled by the motors which are used either to change its orientation , if it gets deflected from its orbit or sometimes to power them so as to get away from any space debris coming in the same orbit which could surely harm the satellite. These satellites usually are divided on the basis of the phases or zones they work in. These could be named as:


  1. LEO or Low Earth orbit. – These satellites orbit our earth at a height ranging from 160-1600 km
  2. MEO or Medium earth orbit– These orbit earth at an height of 10000km to 20000 km and thus are placed at distant places from earth. These are widely used for navigation and locating places. 
  3. HEO or High earth orbit- These stay in orbit of earth to the farthest of points which is 36000 km and are also called geostationary satellites and rotate with the speed of earth and widely used for communication. 


“These satellites and technologies related to have more often helped us in many ways,and would be befitting in future also. But the only thing these add up to is the space debris.These are more often remained in space when there time period gets completed and are left to lose out in deep space. But all of this adds up as junk in space and might be harmful in our future trips to space. But usage of these satellites are more than their disadvantages , and thus have made life on earth More comfortable, knowledgeable and also given birth to a lot more complexities with it”. 

Delineation of watershed in Amravati tehsil using geomorphological investigations through Remote Sensing and GIS techniques

Khadri S.F.R*, Sachin Thakare and Pooja Surkar


In this study an attempt has been made to understand various geomorphological factors controlling the various landforms which in turn helpful in the delineation of watershed in Amravati tehsil through remote sensing and GIS techniques. The study area exposes part of Pedhi River and Kholad River which is a part of Wardha Watershed. The present investigations have helped to understand the groundwater potential as well as nature of the watershed with the help of detailed geomorphological investigations. Satellite remote sensing data as well as topographic data has been widely utilised in this study to identify the watershed and groundwater potential zones with the help of latest available techniques.

The results of the present study demonstrate the presence of various hydro geomorphological zones showing their groundwater potentialities which vary from excellent to poor. The study area covering Pedhi watershed shows excellent to good ground water quality whereas the Kholad and Kapasi watersheds show moderate to poor ground water quality. Overall, the present study demonstrates the useful ness of remote sensing and GIS techniques in the delineation of potential aquifers in the region which plays a major role in the sustainable   management of water resources in the Amravati region.

Key Words: Remote Sensing, GIS, Geomorphology, Watershed, Satellite, Topography.



A watershed can be defined as the area of land that drains to a particular point along a stream. Each stream has its own watershed. Topography is the key element affecting this area of land. The boundary of a watershed is defined by the highest elevations surrounding the stream. A drop of water falling outside of the boundary will drain to another watershed (Sewickley Creek Watershed Conservation Plan, 2003). From a planning standpoint, watershed is considered the most ideal unit for analysis and management of natural resources. For optimal use of environmental resources in a region, integrated watershed development approach is still viewed by many to be the most ideal as it helps in maintaining the ecological basis of resources utilization (Sahai 1988). Geomorphology is defined as the science of landforms with an emphasis on their origin, evolution, form, and distribution across the physical landscape. The science that deals with surface features of the earth, their forms, nature, their origin and development is termed as geomorphology. DAVIS (1912) first projected the concept of geomorphic cycle. According to bauling (1950), the role of factors that are important the geomorphology are lithology, stratigraphy, climatic variation and the regional basis for the development of landforms. The use of remote sensing technology for Geomorphological studies has definitely increased its Importance due to the establishment of its direct relationship with allied disciplines, such as geology, soils, vegetation/Land use & hydrology.

Geomorphological mapping involves the identification and characterization of various landforms and structural features. The various landforms can influence a conservation area in many ways like slope gradient, elevation and aspect, affect the quantity of solar energy, water, nutrients and other materials, while the slope affect the flow of materials. Slope is also the deciding factors of intensity of disturbance, such as fire and wind, which are strongly influenced by the pressure of vegetation (Swanson et al 1988).

Study Area:

Amravati Tehsil basically part of Amravati city and the villages around it lying between 220 45” N to 210 20” N and 770 32” E to 780 02” E. Amravati is District place and major city in Vidharbha region. Amravati names comes from Hindu goddess “Ambadevi”, in Mahabharata epic Amravati is a capital of Vidarbha Naresh, and it is a part of Varhad (Berar).


Amravati Tehsil is bordered with Achalpur tehsil as well as Murtizapur Tehsil in North direction and Chandur Bazar Tehsil touches the boundary in east and west direction. Wardha River is naturally separate Amravati District from Wardha District. Wardha River is a major River of Vidarbha region which is join Painganga River in the boundary of Marathwada. Pohra Malkhed is protected forest area in Amravati. The average elevation is 543m from MSL.


Climate of Amravati Tehsil is hot and dry, April to June Month having extremely heat and temperature goes to 450 C as well as winter season temp goes down 110 C which shows temperature variation, Rainy season start from end of June Month to September in an average.


There are three main types of soil present in Amravati Tehsil which is-

  • Deep Black Soil b) Medium Black Soil           c) Shallow black Soil

Crop pattern:

Amravati Tehsil is having different types of Crop Pattern such as Cotton, Sorghum (Jawar), Green Gram (Moong), Soybean etc. but Amravati tehsil as well as whole District is famous for Orange (Citrus Spp.)


In Amravati tehsil Badnera is Major Railway Station of Central Railway. National Highway 6 is passed through the Amravati Tehsil.Fig.1 shows the location of Amravati Tehsil.

Fig. 1 Location Map of Study Area

Materials and Method:

Data Used

  1. Toposheet Approved by Survey of India Having 1:50000 scale
  2. Satellite Imagery LISS data having 23.5m resolution
  • ERDAS Imagine Remote sensing Software
  1. ARC GIS Software






Fig.2: Flowchart showing the methodology used for Watershed

Software used:

  • Arc GIS 10: This software has been developed by ESRI Inc. it is one of the leading software for desktop GIS and mapping. Arc GIS gives the power to visualize, explore, query, and analyze data geographically. In this project Arc GIS has been used to display raster map, digitizing different features and querying the data for finding the attributes for any feature on map. Arc GIS Spatial Analyst is a tool which helps in analysis and understanding of spatial relationships in our data. Reclassify tool has been used to reclassify different data and raster calculator has been used for overlay analysis and calculation of final results.
  • Generation of contour map: Contours are polyline that connect points of equal value of elevation. The elevation points were prepared from toposheets on a scale of 1:50000 collected from Survey of India (SOI). The collected toposheets were scanned and registered with tic points and rectified. Further, the rectified maps were projected. All individual projected maps were finally merged as a single layer. The contours were digitized with an interval of 10m. The contour attribute table contains an elevation attribute for each contour polylines. The contour map was prepared using Arc Map of Arc GIS 10. Contour map is a useful surface representation because they enable to simultaneously visualize flat and steep areas, ridges, valleys in the study area.

Fig. 3: Contour Map of Amravati Tehsil

  1. Generation of digital elevation model (DEM): A DEM is a raster representation of a continuous surface, usually referring to the surface of the earth. The DEM is used to refer specifically to a regular grid of spot heights. It is the simplest and most common form of digital representation of topography. The Digital Elevation model for the study area was generated from the Tin.

Fig. 4: Digital Elevation Model of Amravati Tehsil

  1. Generation of slope map: The Slope function in Arc GIS 10 calculates the maximum rate of change between each cell and its neighbors. Every cell in the output raster has a slope value. The lower the slope value indicates the terrain is flatter and the higher the slope value, the steeper the terrain. The output slope raster was calculated in both percent of slope and degree of slope. Slope map was prepared from the DEM.

Fig. 5: Slope Map of Amravati Tehsil


  1. Generation of watershed: Watershed of the study area was demarcated using the software Arc GIS. Drainage pattern was taken as the input data.

Fig. 6: Drainage Map of Amravati Tehsil


Fig. 7: Water body of Amravati Tehsil

Fig. 8: Watershed of Amravati Tehsil

  1. Ground Potential zones map: Ground Water Potential Zones map of Amravati Tehsil Shown in fig. 9 having four different types of zone, they are Excellent, Good, Moderate and Poor. The Ground Water Potential Zone of Study area generated with the help of drainages, geomorphology and land use land cover with integration of Remote Sensing and GIS technique as well as Geology of that area plays an important role. Geomorphology of the study area having alluvial plain, Denudation Hills and Platues. During weighed overlay analysis, the ranking has been given for each individual parameter of each thematic map and weights of 25%, 35%, 30% and 10% were assigned according to their influence for Soil, Hydro-geomorphology, Land use/Land cover, and Slope themes respectively and obtained the ground water potential zones in terms of Excellent, Good, Moderate and Poor zones in the form of a GIS map.

Fig. 9: Ground Water Potential Zone of Amravati Tehsil


  1. Geomorphology Map: Geomorphology as a science developed much later than geology although several aspects of geomorphology are embedded in geological processes. Geomorphology deals with the genesis of relief forms of the surface of the earth’s crust. Geomorphological mapping and necessary supporting data are crucial to developing countries that are usually under severe environmental and demographic strains. Approaches and methods to map the variability of natural resources are important tools to properly guide spatial planning. In this paper a comprehensive and flexible new geomorphological combination legend that expands the possibilities of current geomorphological mapping concepts. The piece-by-piece legend forms a “geomorphological alphabet” that offers a high diversity of geomorphological information and a possibility for numerous combinations of information. This results in a scientific map that is rich in data and which is more informative than most previous maps but is based on a simple legend. The system is developed to also be used as a basis for applications in GIS.
  2. 10: Geomorphological Map of Amravati Tehsil

Results and Discussion

Five major watersheds were identified in the area. The area occupied by the largest watershed is 167 Sq.km and it falls under the Sub-watershed category which covers around 66.01 % of the area under study, the second watershed has an area of 37 sq km and this also falls in the sub-watershed category and covers around 14.62 % of the study area, the third watershed has an area of 35 Sq.km and falls in the category of Micro-watershed occupying about 13.83 % of the study area. There are two small watersheds having an area of 5 Sq. Km. and 9 Sq. Km respectively falling in the category of Mini-watershed and covers around 4% of the study area

  • DEM is the 3-D presentation of the surface derived by the interpolation of contour map. It represents x, y and z-axes in pixel size of the order 23.5 meters. The altitude or z axis ranges from 291 meters to 466 meters above sea level
  • Digital slope was derived from DEM on pixel size of order 23.5 meters
  • Ground water potential zones were identified on the basis of slope of the area. Five classes i.e. very good, good, moderate, poor, very poor, were identified. Most of the area comes under very good and good ground water potential zones. The area which has 1-3% slope has very good ground water potential due to nearly flat terrain, area having 3-5% slope has good ground water potential due to slightly undulating topography and some run-off, area with 5-10% slope has moderate ground water potential because these areas have relatively steep slope leading to high run-off, areas with 10-15% and 15-35% slope has poor ground water potential due to steep slope and higher run-off


Geomorphology as a science developed much later than geology although several aspects of geomorphology are embedded in geological processes. Geomorphology deals with the genesis of relief forms of the surface of the earth’s crust. Certain Natural Processes are responsible for the forms of the surface of the earth. The earth’s surface forms are primarily due to hypo gene or endogenous processes, which include diastrophism, leading to geologic structure, tectonic activity and volcanism leading to volcanic landforms.

Alluvial Plain:

An alluvial plain is a relatively flat landform and created by the deposition of highlands eroded due to weathering and water flow in study area. The sediment from the hills is transported to the lower plain over a long period of time. It identified on the imageries dark reddish moderate to fine texture due to agriculture activities. Alluvial deposits of the area constitute gravel, sand, silt or clay sized unconsolidated material. The area under alluvial plain cover in geomorphological map is 246 sq km.

Denudational Hills

Denudetional hills are the massive hills with resistant rock bodies that are formed due to differential erosional and weathering processes. These hills are composed of Vindhyan sediments which are fractured, jointed having no soil cover moderate to steep slope. On the satellite image, these landforms were identified by light or dark brownish with mix green color due to thick forest cover. The area under Denudetional hills cover in geomorphological map is 32 sq km.

Structural Hills

Structural hills are representing the geologic structures such as- bedding, joint, lineaments etc. in the study area. They are located in the eastern parts of the study area having greenish and reddish tone with rough texture on the satellite image. The area under structural hills cover in geomorphological map is 3 sq km.

Flood Plain

A flood plain is an area of land that is prone to flooding. People realize it is prone to flooding because it has flooded in the past due to a river or stream overflowing its banks. A flood plain usually is a flat area with areas of higher elevation on both sides. The area under flood plain cover in geomorphological map is 1 sq km.

Habitation Mask:

A habitation Mask is an area of land that is occupied by human being. It is human settlement area. It is defined as an area of human habitation developed due to non-agricultural use and that which has a cover of buildings, transport, communication utilities in association with water, vegetation and vacant lands. The area under Habitation Mask cover in geomorphological map is 118 sq km.


A plateau is an elevated land. It is a flat topped table standing above the surrounding area. A plateau may have one or more sides with steep slopes. The area under plateau cover in geomorphological map is 458 sq km.

Water Body:

It is an area of impounded water, areal in extent and often with a regulated flow of water. It includes man-made reservoirs/lakes/tank/canals, besides natural lakes, rivers/streams and creeks. The area under water body cover in geomorphological map is 32 sq km.


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