Cat on the wall -1

Blogs and comments are the best way to get people talking. I like to listen to people discussing on a few murky aspects in remote sensing.

The first debate is on "Will contrast enhancement improve supervised classification accuracy?"

Preamble:

Analysts perform contrast enhancement to better visualize their objects of interest. So would this enhancement improve the between-class separability?

Scenario 1:

The analyst contrast stretches the image and chooses the training pixels. He burns the LUT (look up table) to create a new image. He uses the same training pixels for classification in the original image and on the stretched image.

Scenario 2:

The analyst uses a different set of traning pixels on both the images.

I would like to know your opinion on the results of the two scenarios. Which one would you consider better and the reason.

National Action Plan on Climate Change (NAPCC)

ISRO's contributions in climate change studies

This document is a condensed version of the original ISRO report titled 'National Action Plan on Climate Change – Strategic plans and technology initiatives from space'. The purpose is to provide the enlightened reader the list of activities planned and their contents at a glance.

Executive summary

The Prime Minister has earmarked 8 comprehensive projects to understand and tackle climate change. Out of this, ISRO has opted to carry out 6.

ISRO's array of data sources

Earth Observation Systems

• 8 operational RS satellites
  
  • IRS 1C, 1D, P3, Oceansat -1, TES, Resourcesat -1, Cartosats -1,2
    
• Meteorological satellites
  
  • INSAT 1,2,3, METSAT (Kalpana -1)
    
    • VHRR sensor covering 0.55 – 0.75 µm region with 2x2 km resolution
      
    • Thermal sensor covering 10.5 – 12.5 µm region with 8x8 km resolution
      
    • Water vapour sensor covering 5.7 – 7.1 µm region with 8x8 km res.
      
• Future missions
  
  • Resourcesat -2, Cartosat 2 series, Oceansat -2, RISAT, SARAL, Megha Tropiques
    
  • INSAT series with imagers, sounders and GeoHR imagers.
    

Ground Systems

• AWS (Automatic Weather Stations), AGROMET towers, DWR (Doppler Weather Radar) are used under the present GBP (Geosphere Biosphere Programme), ASP (Atmospheric Sciences Programme) in association with IMD (India Meteorological Dept.), MoES (Ministry of Earth Sciences), SASE (Snow and Avalanche Study Establishment).
  

Vertical Atmosphere Observation Systems

• GPS sonde (Pisharoty sonde) – (Temperature, Pressure, Humidity, wind parameters)
  
• Boundary Layer Lidar (BLL) – aerosol, boundary layer heating
  
• Multi Wavelength Radiometer (MWR) – columnar spectral size distribution of atmospheric aerosol optical depth
  
• TIFR Balloon Facility –to send payloads to upper troposphere, stratospheric altitudes.
  

National action plan on climate change

ISRO's strategic inputs for NAPCC is 6 comprehensive missions

The logistics and procedure for each of these missions is presented in the following sections.

Sustainable habitat

1. LULC (Land Use, Land Cover) assessment
   
   1. 1:250,000 for 5 years for cropping area and patterns
      
   2. 1:50,000 national wasteland map
      
   3. NUIS (National Urban Information System) – Urban GIS – ecological footprint of the resources, energy, infrastructure for SD of urban environment
      
   4. LULC changes in 14 river basins of India for 3 decades.
      
2. Keystone ecosystem of Indian coast
   
   1. Mangroves, coral reefs, sea grass monitoring
      
   2. Sea level rise and vulnerability index maps for next 25, 50, 100 years.
      
   3. Monitoring the shift in SST (Sea Surface Temperature) – shift from coral reef dominated habitat to micro algae dominated habitat.

National water mission

1. Water resource assessment
   
   1. Mapping, monitoring and management of water resources
      
2. Performance of irrigation commands
   
   1. Using temporal data, assessment of low performing catchments. Adaptation of new strategy, appropriate actions to augment and sustain productivity
      
3. Irrigation infrastructure
   
   1. AIBP – accelerated irrigation benefit programme.
      
   2. Use of high resolution RS data to monitor the physical progress.
      

Sustaining himalayan ecosystem

1. Snow and glacier
   
   1. IRS LISS 2 -> 1:250,000 map of Himalayas. 1702 glaciers covering 23,300 sqkm were found.
      
   2. Studies on glacial retreat, negative mass balance, early melting of seasonal snow, wintertime increase in stream runoff
      
   3. MSMR – monitoring of Antarctic region
      
   4. Snow cover monitoring of 28 sub basins of Indus, Ganges using AWiFS data
      
2. Biodiversity – western Himalayas regions of JK, HP, Utt, NE using GPS ground survey for vegetation type distribution
   
3. LU LC changes for 30 years on 14 river basins of GBP
   
4. Temporal satellite data – invasion of vegetation to higher altitudes. Vegetation ingression and timberline shift are indicators of climate change.
   
5. Bioclimatic index – quantification of areas and the extent of change.
   

Greening India

Some of the major LULC mapping projects relevant to this theme are

1. NR census – 2005 (ongoing)
   
2. NR census for land degradation using temporal data – 2005 (ongoing)
   
3. National wasteland mapping – 1986-99; 2003-06
   
4. LULC using AWiFS – 2005-08
   
5. LULC mapping for planning based on agro climatic zones – 1989-90
   
6. Nationwide wetland mapping – 1995 (ongoing)
   
7. Urban sprawl of million plus cities – 1988-90
   
8. Urban sprawl Information System – 1990
   
9. Integrated mission for sustainable development – 1992-98
   
10. Integrated resource for desert areas – 2002
    
11. INFFRAS – Indian Forest Fire Response and Assessment System using IRS, MODIS. Archived data from 2006 is available.
    
12. Bhoosampadha – WebGIS – LULC data, temporal snow cover, water bodies information all in raster format.
    

National mission on sustainable agriculture

1. IMSD – integrated mission for sustainable development to cover 174 districts, 84 Mha land and maps at 1:50,000 scale
   
2. IRIS –DA Integrated resource information system – Desert Areas.
   
3. Sujala – MIS for policy formulation, action plan, short and long term goals
   
4. AWiFS data, 3 times 1:250,000 for LULC under NR census programme
   
5. Inseason agricultural drought for 4 states using AWiFS data and 9 states using NOAA / AVHRR data
   
6. Landsat MSS, LISS soil resource maps at 1:250,000 to 50,000 covering the themes land capability, irrigability, erodability, retentivity, suitability for difference crops.
   

Strategic knowledge for climate change

1. Atmospheric Chemistry
   
   1. Methane emission from rice fields and seasonal integrated flux of rice ecosystem is computed
      
   2. Wetland maps –to calculate annual emission from wetlands
      
   3. Monitoring atmospheric chemistry of CO, CO₂, NO_x, O₃ using ENVISAT SCIAMACHY (SCanning Imaging Absorption spectrometer for Atmospheric CHartographY), GOME
      
2. Atmospheric aerosols
   
   1. GBP studies – 3 times increase in coarse particle abundance over mega cities – Delhi, Pune
      
3. RCM – Regional Climate Model – over 30x30km region and assimilating boundary conditions using RS data
   
4. Forest and agricultural carbon fluxes using RS and insitu data to understand carbon flux change due to afforestation and crop growth scenarios.
   
5. Impact of LC change on monsoon. It is observed that NDVI and vegetation fraction have positive relationship with monsoon.

Above the abode of clouds

My two-month long training programme came to an jolting halt. After the good byes and contact exchanges, I was left stranded in the Ahmedabad airport. I was the lone person from the group leaving to Bangalore. I patiently waited for two long hours for my much coveted window seat. It certainly seemed childish for the co-passengers to watch a grown up fellow peeping only through the window all through the journey. Yet, I was generous enough to let them look through the window during the takeoff and landing; perhaps they had an idea of waving to their loved ones as they flew over their rooftops.

  Air travel is like physics practical to me. Every time I fly, I learn a lot new things, encounter several natural phenomena and get several questions answered. This time is no exception. We took off in the early evening at 4:30 pm, the sun shone brightly at midway to the horizon from the zenith. We were travelling due south and the sun was to my right. I certainly had to thank Suganya for booking the seat on the sunny side; although, my co-passengers had a tough time getting sleep, as mine was the only window open in the entire right side of the plane.

Much as expected, the skies of the peninsular India were 

 blanketed with clouds. Most of them perhaps should be of convective origin. While most of them were seen stitched to one another, there were a 

few gaps and individual cloud groups formed a spectacle in the sky. The sun being the only source of illumination, but from an infinite distance sends its rays parallel to Earth. These clouds with high albedo and density remain largely opaque to the light. The result, beautiful parallel rays of light, just as you see in devotional pictures.

At 35,000 feet (11,666 meters) above the ground, we were flying at the higher end of the troposphere. The temperature as the captain echoed was sub zero outside and the pressure was considerably less. Only at these low pressures, or less denser atmospheres, we get the chance to see, of what I would call an invaluable picture. The sun above the horizon shone as a clear white ball, the clouds appeared white, the sky above was blue, but the reflection of the sun from the ocean below was red! How could this happen? To me, at 11.6 km above the ground, sun shines directly and appears least distorted in white, but to the waves on the beach, the rays have to inevitably pass through the denser atmosphere. Further, the evening condition takes the rays through a longer path through the atmosphere where wavelengths up to green get scattered as per Rayleigh law and only reddish orange light reaches. This light further has to pass through the same atmosphere to reach my eye where after additional scattering appears reddish.

As we moved a little further, the cloud cover started growing denser. Soon, it was beyond a point where I could no longer see any ground. These low altitude dense clouds should have been cumulous. They had a fluffy appearance and the evening sun shining obliquely caused small shadows adding to their coarse texture. All of a sudden, I wondered if I were flying above the arctic pole! These very much resembled the polar ice caps.

About an hour passed since we started, and I guessed we must have been at the mid section of the peninsula. The cloud cover had died with the calm interior of the Arabian sea beneath. Although the sea surface in general had a moderate brightness due to scattering because of the wave induced surface roughness, there were a few apparently dark spots seen. As we kept flying, my look angle changed, and when I came directly in line with them, they shone off too brightly. It was just like a mirror. Only then I understood these must have been oil spills. 

These notorious spills form a layer on the waters which are comparatively static and hence behave as specular reflectors. Further, they inhibit the mixing of gases with the sea water at the boundary layer reducing the dissolved oxygen content and causing a potential peril to the aquatic lives.

I wondered whether at this height, I could see a boat or a ship; a little later I found the answer to be yes and no. Although it is not possible to see a small boat, one can see the trails it leaves behind. Generally, the trails are much larger than the boat itself and because of the churning, they appear white and this can be seen from the sky. I recollected how satellite images are used for surveillance; while they cannot resolve tiny boats, they effectively pick up their trails and help calculate the velocity and direction of the boats.

Another hour passed, at 6:30 pm the earth has rotated considerably and sun had declined below the ground horizon; its rays now had to travel through the notorious atmosphere reaching me in red. I feel it is this atmosphere which makes our planet special, for life to exist and climates to sustain. This seemingly transparent and innocuous layer has telltale effects on our lives. Atmosphere means differently to different people, for me, it is a domain less understood, less modeled, an adventure and my area of research.

Are you the Martian the world is looking for?

“Martian water has been touched and tasted” quotes a triumphant report from NASA. The Phoenix lander has been doing phenomenal research on the Martian soils. The MRO (Mars Reconnaissance Orbiter) has been beaming radar images of the surface and subsurface of Mars for over 4 years. Huge teams of scientists, ET (extra terrestrial) geologists, from across the world regularly analyze these data searching for vital clues to know if life ever existed or could exist on that red planet.

Since the beginning of the 19th century (or perhaps, since humankind could develop powerful optical telescopes) our curiosity for Mars is afresh. People in every walk of life from planetary observers to common man like you and me are interested in knowing about this mysterious neighbour. The number of spacecraft missions to Mars between 1960s to 2000 is a whooping 37, which holds testimony to our relentless search for knowledge about this planet.

What are we indeed looking for? Water? Minerals? Rare metals? Fuel? Or life itself? What is that one thing which pins is down to this planet? Despite finding frozen water beneath the surface of Titan (moon of Saturn), our search in Mars has never been quenched.
“Part of the reason we are so eagerly searching for extraterrestrial life is that we have not yet determined the origins of life on the Earth!” writes Dr. Alexander Bagrov from the Russian Institute of Sciences. This is the turning point in the story.

Why could it not be, that life on Earth was impregnated from Mars?

Why could it not be, that an earlier, more sophisticated life form from Mars has seeded our evolution? I believe the whole problem has to be seen from this new perspective.

I may sound absurd or wildly imaginative, but if you can fix the results from various explorations together, you may end up in my favour. “The images from Mars3 orbiter depict features which looked very much like river canyons. This made scientists wonder if water had existed on Mars! We now know that Mars was once a warm and humid planet with rivers presumably capable of supporting life” writes Bagrov. Facts like these only add to my claim.

Yes, I hear your question. Although we don’t quite well know about the origin of life on Earth, we have proved scientifically about evolution and how complex organisms evolved from the simplest amoeba. If such would be the case, how could life come from Mars?

To answer this question, we must review that one factor which is hindering human space travel – COSMIC radiation. These high energy rays would spare space crafts, but cause fatal mutations in complex organisms. Hence our ancestors in Mars should have been left with the only option of protecting and sending the simplest of all life forms – amoeba.

Mankind has always been thirsty to know its own roots, whether be the attachment to races or the highly scientific global genome mapping project. Perhaps this is one such search. We should await until the bigger picture unfolds.

Global Food Crisis - the urban animal’s work of art

Global food crisis, food scarcity – page after page, every paper, every channel, every meeting in the cabinet moots about this eerie subject. Ministers, economists, chiefs of the countries are yet to get relieved from this shock. On one hand there are articles of condemnation on the poor countries’ plight and on the other richer countries asserting themselves that their citizens would not starve.

The World Food Program (WFP) has recently identified at least 30 “high risk” countries from around the globe and 21 among them are in Africa. A 100 million people are now urgently at risk of not having enough food to eat – a report from the United Nations shudders. With one child dying every five seconds from hunger-related causes, the time to act is now," Gordon Brown, the Prime Minister of Great Britain stresses in a meeting. The WFP has characterized this as the ‘Silent Tsunami’ warning that may lead to a potential catastrophe.

Why? When? How did this start? Did the population surge suddenly? Did the monsoons fail? Did the climate change and global warming burn down all the crops? Or did we all just start to munch more? None of the above!

We have foolishly inflated our own currency. Food has become increasingly costlier. Wheat prices have increased by 200%. Grains are available in the market but just that nobody can buy it. This season Cambodian farmers witnessed a harvest which they claim is the best in memory; but this has not shielded them from the global food scarcity. Why? Because food is becoming less and less affordable to those who grew it! Millions more of the world's most vulnerable people are facing starvation as food shortage looms and crop prices spiral ever upwards.

Short of cash, the World Food Program (WFP), the UN agency which feeds the world’s poorest people, can no longer supply 4,50,000 Cambodian children with its breakfast. WFP estimates it needs an additional $500 million to keep feeding the 73 million people in Africa, Asia and Central America. The increasing cost of grains is also pushing up the price of meat, poultry, eggs and dairy products. And there is every likelihood that prices will continue their relentless rise, according to expert predictions by the UN and developed countries.

Food, not for people, but for cars!
Bio fuel is another culprit. The global drive for a new green fuel to power cars, lorries and planes is worsening world food shortages and threatening to make billions go hungry. Biofuels, enthusiastically backed by the US, UK and other European governments, have been sold as the solution to global warming. Converting large amounts of land to crops for biofuels is reducing food production just when the world needs to increase it.

When the crisis retaliates
For the first time in history, say experts, the impact is spreading from the developing to the developed world. Wal-Mart’s cash and carry division, Sam’s Club, announced it would sell a maximum of four bags of rice a person to prevent its supplies from running short. This is the face of new hunger. Experts lament that even those better off countries which erstwhile were never under their scanner are presently at the risk of this scarcity.

With every bite of food we consume, we should remember that we all have played a part in this inflation. Our government / company pays us various allowances which grow up each year. We have lived with this inflation without knowing it. But who gives them to our farmers? They live as isolated servants who ensure that our bellies are always full while putting theirs on starvation. These poorest of the poor suffer silently, too weak for activism or too busy raising the next generation of hungry. As responsible citizens, we are obliged to uplift the plight of our farmers. Let us act now.

A Bangalore fly-by

It was a beautiful sunset and a busy evening; I packed my back-pack as I had to leave to Hyderabad from Coimbatore after a long vacation. Those long years in college and the grooming as a corporate professional could remotely change my attitude from a whining school boy reluctant to leave home for school. I found hard to push myself to leave for work the next day.
As I waited in the verandah, dad arrived and we left for the Coimbatore domestic airport. Ours is a simple, small and a quiet airport, much unlike that of any other metro in India. The serene look and the calmness in the milieu had a soothing effect; I and dad drifted to our chat soon. We started with the world of IT and when we finished talking about grid computing I realized that only 20 minutes were left for the take off!

When I entered the airport, the security check had finished and I was the last one to report! The routine screening and checks were over and I found myself sitting beside a window inside the airplane. The aircraft took off, houses, roads and people became miniatures; the horizon expanded and the strange bliss I acquire every time I flew arrived – perhaps it was the desire to become a photogrammetist which was getting fulfilled, at least partially.
I flipped open my sony phone in in-flight mode and tried my best at capturing the beauty of rustic India at sunset. Alas, the cabin lights were too bright and caused an internal reflection subverting my photography. I settled with the Deccan Airways magazine and skimmed quietly through it.

An hour passed and raspy voice echoed through the speakers. The captain announced the bearings, the 17,000 ft altitude, 490 kmph velocity and the -2°C outside temperature. What he announced next was had such a lasting impact on me that it motivated me to write this entire article. It was the Bangalore fly-by; a night vision of Bangalore from the sky.

Hurriedly, I switched off the reading light and peeped down the window. I was awe-struck. I saw the Las Vegas of India, our silicon city dazzling with its jewel like lamps. Glistening, sparkling lights, the traffic inching through the roads gave the reality of Bangalore even from the sky. An arterial road looked like a sparkling platinum chain and a splatter of lights forming a disc below it looked like a dollar and on the whole I saw a mammoth necklace dazzling in the night.The plane canted to its right and I got an even better vision of the city. The roads emerged clear with their street lamps, ambient glow from roadside shops, discrete and berserk run of vehicle lamps. From the sky this vision recalled that of an artery and the red blood corpuscles rushing down it. Now anyone who had seen this would know why, are these roads termed as arterial!The sight was so irresistible; I had to pen down those few words that blurt out of my mind during my first sight, thankfully my habit of carrying the ATM slips came to rescue. As I jotted down these visions on the back of the slips, I saw the air hostess watching me with a tinkle in her eye depictive of surprise and joy.

This fly-by lasted for just ten minutes after which I saw the dull and occasional sparks of light from the suburban places below. The sporadic distribution of lights appeared in unique and peculiar shapes. Those clusters of tiny lights in abstract shapes looked as if it were a weird communication with aliens.

In another half hour the plane landed in the brand new Shamsabad airport, Hyderabad. The airport was gleaming clean an obviously fine work from GMR group of companies. With the geographer and writer satisfied in my, I started towards the office.

Solar Spheres

On a busy and darkening evening, I strolled down the streets of Hitec city, Hyderabad. Mammoth buildings, edifices, dazzling office spaces, lounges, non-stop air conditioning machines, ever running computers and servers, and on the whole the entire new city was a giant energy guzzler. As I reached the 13th floor of the service apartment in which I lived then, the entire Hitec city looked like Las Vegas, bleached with glaring lights! - all in a time where we proclaim about carbon control and global warming.

I called it a day as I was tired and retired to bed. But I was annoyed thinking where all this might lead us to. As I closed my eye, my thoughts drifted to a series of abstract possibilities and wired ideas. I wish to share it with all my environment conscious friends (green warriors) though this article.

We all know about super-conducting materials (those with zero resistance to conduction of electricity). What if we were able to make super-reflecting materials? Materials which are ultra efficient than mirrors and thus the quantum of energy impinging on the surface is always equal to the quantum of energy getting reflected. Thus the material remains to be in absolute inertness with respect to Electro Magnetic Waves.

So how would these materials behave?
Well, if you were to keep two super-reflecting mirrors facing each other, and if you were to focus a laser beam onto on of the mirrors for a fraction of a second, the ray of light from the laser would get reflected from mirror A to mirror B and back to A. This way the cycle repeats a number of times.
While in usual cases this series of reflection would die down in a fixed extent of time since the intervening air particles and to a minute extent the mirror surface would absorb the light.
But, when this experiment is conducted in absolute vacuum with super reflecting mirrors, the cycle would become endless, no matter even after millions of years.

Now how will this help us?
Let us construct a hollow sphere whose inner surface is super reflecting. On the north pole of the sphere, there is a unidirectional vent with a lid through which sunlight is allowed to enter for a fraction of a second. Since the space inside the sphere is devoid of air, this quantum of EMW would undergo an endless reflection spree. We could examine this activity if we place a CCD sensor on the south pole of the sphere. Since the CCD sends a pulse of electric current by converting the light which impinges on it, our energy inside the sphere would have a mild time-decay function. If we replace the CCD sensor with a solar cell, we are now generating power!

From a pragmatic propensity
Giant solar spheres can be manufactured in large scale. These structures would have larger uni-directional vents with automatic lids – perhaps of the kind of polaroids. A number of solar cells can be disbursed on the inside of the sphere - just like doping a semi-conductor. These cells would lie under smaller polaroid lids whose outer surface is also super-reflecting. Thus when the smaller lids cover the solar cells, the inside of the sphere is 100% super-reflecting.
Now, during the day time, we would open the top lid of the sphere allowing sun’s rays to enter the sphere close them instantly. Since the smaller polaroid lids cover the solar cells, the light inside the sphere would remain alive to eternity. Then, during the night hours (or during the needy hours) we would like polarize the smaller lids, thus opening the solar cells beneath to face the inside of the sphere. Whenever a quantum of light hits a cell after undergoing eternal reflection, it gets converted to electric current. This way until the last quanta of light is used up, we can generate solar power.

How good is our idea?
On a production scale, solar spheres would require nothing more than a few thousand solar cells, polaroid covers and our new super-reflecting material.
The following are the advantages

• This method is maintenance free. Since the inside is vacuum, there is no means by which the apparatus could get damaged.
• The outer shell can be made of steel / concrete as per the convenience and it is an one time investment.
• There is no wear and tear.
• The energy is 100 % clean without any emissions. Thus it is the safest source of power.
• Energy can be generated instantly or could be stored up and generated after a million years too.
• It is the best way to store electric power. Compared to super-conducting materials which should be maintained at sub zero temperatures, this ultra simple apparatus stores electricity with no loss for endless amount of time.

It’s quite conspicuous that Geo Dexter feels Solar Spheres would be the most feasible solution to our pressing demands of energy.