cloud computing and satellite imagery

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The document introduces to the concept of cloud computing and how it can be and is being used in the world of satellite imagery?

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Page 1: Cloud Computing and Satellite Imagery

CLOUD COMPUTING & SATELLITE IMAGERY

Anupam Tiwari :[email protected]

INTRODUCTION

1. Opportunities for improving IT efficiency and performance through centralization of resources have increased dramatically in the last few years with the maturation of technologies such as SOA, virtualization, grid computing, and management automation. A natural outcome of this is what has become increasingly referred to as ―cloud computing‖, where a consumer of computational capabilities sets up or makes use of computing ―in the cloud‖ (i.e. over a network) in a self-service manner, without direct involvement in how that computing is resourced. The cloud in cloud Computing provides the means through which everything — from computing power to computing infrastructure, applications, business processes to personal Collaboration can be delivered as a service wherever and whenever you need. Having made a bizarre explosion of millions of possibilities and advantages at the door step of the regular commercial and single user customer, how can sky be left behind alone? The awesome power of the cloud computing has not left the skies unaffected. 2. The growing prevalence of instruments and sensors deployed to continuously observe nature at fine spatial and temporal granularity is causing a surge in the volume of observational data collected, leading to increased resource needs for storing, managing, analyzing and sharing it. This is particularly true for data that stream in from various satellites.Much of data is collected and managed at the long-tail of scientific research, legacy tools running on single-system servers serving a small community of users. 3. Cloud computing is emerging as a viable platform for executing these scientific workflows and/or their constituent tasks . Clouds hold the promise of on-demand availability of computation and data resources using simple service abstractions .Cloud resources are more accessible to a large fraction of scientific users, when compared to costly capital and management costs of local clusters or the complexity and access limitations.

AIM 4. To study the concept of cloud computing and explore possible applications of the same in the field of satellite imagery.

SCOPE 5. This article will be covered as under : (a) Part-I : Basic Concept (b) Part-II : Applications (c) Part-III : Deployment models (d) Part-IV : Satellite imagery & Cloud (e) Part-V : Case Study

(i) Nebula @ NASA Cloud Platform (ii) Server Sky

(f) Part-VI : Security issues (g) Part-VII : Conclusion

Page 2: Cloud Computing and Satellite Imagery

PART 1 : BASIC CONCEPT 6. Cloud computing portends a major change in how we store information and run applications. Instead of running programs and data on an individual desktop computer, everything is hosted in the ―cloud‖—a nebulous assemblage of computers and servers accessed via the Internet. Cloud computing provisions access to all applications and documents from anywhere in the world, freeing one from the confines of the desktop and making it easier for group members in different locations to collaborate. Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. 7. To make it in more simple words, with traditional desktop computing, we run copies of software programs on each computer we own. The documents created are stored on the computer on which they were created. Although documents can be accessed from other computers on the network, they can’t be accessed by computers outside the network. The whole scene is PC-centric. With Cloud Computing, the software programs no more run from the traditional personal computer, but are rather stored on servers accessed via the Internet. If our computer crashes, the software is still available for others to use. 8. Anyone with permission can not only access the documents, but can also edit and collaborate on those documents in real time. Unlike traditional computing, this cloud computing model isn’t PC centric, it’s document-centric. It is not important that which PC is being used to access a document. What Cloud Computing Isn’t ? 9. First, cloud computing isn’t network computing. With network computing, applications/documents are hosted on a single company’s server and accessed over the company’s network. Cloud computing is a lot bigger than that. It encompasses multiple companies, multiple servers, and multiple networks. Plus, unlike network computing, cloud services and storage are accessible from anywhere in the world over an Internet connection; while network computing access is over the company’s network only. What Cloud Computing Is ? 10. Key to the definition of cloud computing is the ―cloud‖ itself which is a large group of interconnected computers. These computers can be personal computers or network servers; they can be public or private. For example, Google hosts a cloud that consists of both smallish PCs and larger servers. Google’s cloud is a private one (that is, Google owns it) that is publicly accessible (by Google’s users).This cloud of computers extends beyond a single company or enterprise. The applications and data served by the cloud are available to broad group of users, cross-enterprise and cross-platform. Access is via the Internet. Any authorized user can access these docs and apps from any computer over any Internet connection. And, to the user, the technology and infrastructure behind the cloud is invisible. It isn’t apparent whether cloud services are based on HTTP, HTML, XML, JavaScript, or other specific technologies. 11. There are six key properties of cloud computing which are depicted below in the figure :

Page 3: Cloud Computing and Satellite Imagery

PART 2 : APPLICATIONS & KEY FEATURES 12. The applications of cloud computing are practically illimitable. With the right middleware, a cloud computing system could execute all the programs a normal computer could run. Potentially, everything from generic word processing software to customized computer programs designed for a specific company could work on a cloud computing system.In broad terms,the following services and applications are offered by cloud computing :

(a) SaaS (Software as a Service) (b) PaaS(Platform as a Service) (c) IaaS(Infrastructure as a Service) (d) DaaS(Data as a Service) (e) Storage as a Service

13. SaaS : Cloud application services or "Software as a Service (SaaS)" deliver software as a service over the Internet, eliminating the need to install and run the application on the customer's own computers and simplifying maintenance and support. 14. PaaS : Cloud platform services or "Platform as a Service (PaaS)" deliver a computing platform and/or solution stack as a service, often consuming cloud infrastructure and sustaining cloud applications. It facilitates deployment of applications without the cost and complexity of buying and managing the underlying hardware and software layers.Regular use platform by various companies include iCloud,CLOUDO,eyeOS etc. 15. IaaS : Cloud infrastructure services, also known as "Infrastructure as a Service (IaaS)", delivers computer infrastructure - typically a platform virtualization environment - as a service. Rather than purchasing servers, software, data-center space or network equipment, clients instead buy those resources as a fully outsourced service. Suppliers

CLOUD COMPUTING

User-centric

Task-centric

Powerful

Accessible

Intelligent

Programmable

KEY PROPERTIES OF CLOUD COMPUTING

Page 4: Cloud Computing and Satellite Imagery

typically bill such services on a utility computing basis and amount of resources consumed (and therefore the cost) will typically reflect the level of activity. IaaS evolved from virtual private server offerings. 16. DaaS : Data as a Service is based on the concept that the data, can be provided on demand to the user regardless of geographic or organizational separation of provider and consumer. Additionally, the emergence of service-oriented architecture (SOA) has rendered the actual platform on which the data resides also irrelevant.

CLOUD STORAGE 17. Storage as a Service : Cloud storage is networked online storage where data is stored on multiple virtual servers rather than being hosted on dedicated servers. Hosting companies operate large data centers; and people who require their data to be hosted buy or lease storage capacity from them and use it for their storage needs. The data center operators, in the background, virtualize the resources according to the requirements of the customer and expose them as storage pools, which the customers can themselves use to store files or data objects. Physically, the resource may span across multiple servers.Cloud storage services may be accessed through a web service application programming interface (API), or through a Web-based user interface. 18. In addition to the key Features listed vide para 11,the following advantages augment the concept :

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PART 3 : DEPLOYMENT MODELS

19. Four deployment models are discussed below :

(a) Public Cloud: In simple terms, public cloud services are characterized as being available to clients from a third party service provider via the Internet. The term ―public‖ does not always mean free, even though it can be free or fairly inexpensive to use. A public cloud does not mean that a user’s data is publically visible; public cloud vendors typically provide an access control mechanism for their users. Public clouds provide an elastic, cost effective means to deploy solutions.

(b) Private Cloud: A private cloud offers many of the benefits of a public cloud computing environment, such as being elastic and service based. The difference between a private cloud and a public cloud is that in a private cloud-based service, data and processes are managed within the organization without the restrictions of network bandwidth, security exposures and legal requirements that using public cloud services might entail. In addition, private cloud services offer the provider and the user greater control of the cloud infrastructure, improving security and resiliency because user access and the networks used are restricted and designated.

(c) Community Cloud: A community cloud is controlled and used by a group of organizations that have shared interests, such as specific security requirements or a common mission. The members of the community share access to the data and applications in the cloud.

(d) Hybrid Cloud: A hybrid cloud is a combination of a public and private cloud that interoperates. In this model users typically outsource non business-critical information and processing to the public cloud, while keeping business-critical services and data in their control.

Key Advantages

Agility Cost

Device/Loc independence

Sharing of resources

Centralization

Peak-load capacity

Utilization

Scalability & Reliability

Security??

Maintenance

Metering

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PART 4 : SATELLITE IMAGERY & CLOUD STORAGE

20. Satellite imagery consists of photographs of Earth or other planets made by means of

artificial satellites. There are four types of resolution in context of satellite imagery in remote

sensing which include the following :

(a) Spatial resolution is defined as the pixel size of an image representing the size of

the surface area (i.e. m2) being measured on the ground, determined by the sensors'

instantaneous field of view (IFOV);

(b) Spectral resolution is defined by the wavelength interval size (discreet segment of

the Electromagnetic Spectrum) and number intervals that the sensor is measuring;

(c) Temporal resolution is defined by the amount of time (i.e. days) that passes

between imagery collection periods;

(d) Radiometric resolution is defined as the ability of an imaging system to record

many levels of brightness (contrast for example).Radiometric resolution refers to the

effective bit-depth of the sensor (number of greyscale levels) and is typically

expressed as 8-bit (0-255), 11-bit (0-2047), 12-bit (0-4095) or 16-bit (0-65,535).

21. Owing to relatively brobdingnagian and critical requisites of high resolution of the received satellite images, further results in demand of large capacity storage requirements of data. In such scenario’s cloud architectures can come to rescue to easily and conveniently provision larger amounts of storage and computing power; they also offer easy access to centrally located information reachable through any compatible device a user wishes to implement; they can provide a back-up to locally stored data; they allow people to easily share their data with others. But at the same time there is always going to be an optimum 'balance point' that identifies the 'best' mix of local (PC) processing and storage, on-premise (enterprise data centre) processing, storage and networking, as well as 'cloud' processing. That balance point changes would again be dependent on the relative cost-effectiveness of processing power, storage, and data communication changes. The advantages are briefly mentioned below :

(a) Investment only for storage that is used and no idle & wasted space.

(b) No need to install physical storage devices in their datacenters or offices, which reduces IT and hosting costs.

(c) Storage maintenance tasks, such as backup, data replication, and purchasing additional storage devices are offloaded to the responsibility of a service provider, allowing organizations to focus on their core business only.

PART-V : Case Study Brief

NEBULA @NASA : Cloud Computing for a Universe of Data 22. Nebula combines cloud computing and data center containers. It is a new data powerhouse, which provides on-demand computing power for NASA researchers. The Nebula application lives in a 40-foot container at the NASA Ames Research Center in Mountain View, Calif. The ―data center in a box‖ was built inside a container from which is filled with Cisco Systems’ Unified Computing System and servers from Silicon Mechanics.

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23. Nebula is a self-service platform built from open source software that provides high capacity computing, storage, and network connectivity for NASA research. It has been designed to automatically increase the computing power and storage available to science- and data-oriented web applications as demand rises. Nebula thus allows for rapid expansion of IT infrastructure, and can provide excellent energy efficiency by offering more precise control of airflow within the container. It provides high-capacity computing, storage, and network connectivity and uses a virtualized, scalable approach to achieve cost and energy efficiencies 24. The project began in 2007 and is an open-source project and uses a variety of open-source components, including Eucalyptus, Lustre and RabbitMQ.The Ames Internet Exchange hosts the Nebula Cloud, and also provisions Nebula to connect with 10 GigE connections. 25. Nebula provides three classes of storage:

(a) Local Storage: Virtual Machines use local storage to run, but the information is local disk and is not saved by default. Nebula uses hot-swappable commodity drives in a hardware RAID configuration. This allows up to 3 drives to fail before data loss occurs. (b) Persistent Block Device (iSCSI): Nebula uses iSCSI to provide a persistent network storage block device. This storage is always backed up. This type of storage can be used by conventional applications that have not been converted to cloud architectures. This allows highly-reliable and permanent storage, and decouples the storage from the connected server as a single point-of-failure. (c) Object Store: With Object Store, it is easy to store petabytes of data and billions of files. Open-Source implementations of object stores have been used with custom code that adds in the access control layer (ACL) and management and potentially the API layer.

26. Thus when we speak of benefits of the same, all the advantages as listed vide Para 18 automatically get augmented with the subject attempt including Rapid Provisioning, Cost Savings, Resource Elasticity, Scalability, Integrated Reporting and Policy Compliance etc.

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SERVER SKY 27. A typical server farm is a collection of computer servers usually maintained by an enterprise to accomplish server needs far beyond the capability of one machine. Server farms often have backup servers, which can take over the function of primary servers in the event of a primary server failure. Server farms are commonly used for cluster computing. Many modern supercomputers comprise of giant server farms of high-speed processors connected by either Gigabit Ethernet or custom interconnects such as Infiniband or Myrinet. 28. Server sky is a proposal to build large dispersed arrays of ultra light solar powered server satellites and launch them into 6000km earth orbit, between the inner and outer Van Allen belts. A 50 gram server-sat consists of a thinned 12 inch solar cell, with an efficient 2GIPs processor, terabit solid state disk, and microwave transmitter bonded to the back. Thousands of server-sats position themselves into dozens of dispersed three dimensional clouds (kilometers on a side) using light pressure for thrust and liquid-crystal shutters for trim tab steering. A server-sat array acts as a large phased array antenna, permitting it to steer thousands of communication beams at receiving stations and communities under its position in orbit, handing off communication and control to the server-sat clouds that follow it in orbit as it passes overhead. 29. Since server-sat arrays operate outside the biosphere, the environmental impact of power generation and heat disposal is close to zero. Server-sat arrays can grow to practically unlimited size – space is big, and filled with unused solar energy. In time, new launch techniques, and solar cells made from lunar rock, can greatly reduce the environmental and economic costs of manufacturing and launch. There is room for 1 trillion server-sats within a 100 millisecond ping time distance from earth. Someday, quintillions of server-sats scattered around the solar system will perform cluster computation.

PART-VI : SECURITY ISSUES 30. Cloud computing is revolutionizing how organizations are constructing their networks and systems; it is changing how organizations invest in their information technology infrastructure; and it is forcing organizations to reconsider how they secure critical information—security is critical and at the forefront of cloud computing. The obvious security concerns include data integrity, data availability, protection of personally identifiable information, data protection, data destruction, and communications security. Trust, security and privacy always pose issues in any internet provided service, but due to the specific nature of clouds, additional aspects incl issues related to multitenancy and control over data location etc. arise. Thus new security governance models & processes are required that cater for these specific issues arising from the cloud model. 31. Data and operations security are largely alleviated by today’s mature scalable and redundant multitier architectures, and shared resources environments. Third-party data centres offer facilities to isolate customer data, perform regular backups, and minimize failure through redundancy. Detailed service level agreements spell out responsibilities. There are standards for disaster recovery and business continuity to protect ,PaaS,IaaS, SaaS etc customers.But irrespective of agreements, building confidence measures, it is a well understood fact that all these security claims are somewhat limited in nature. 32. The cloud computing industry is in the early stages of the technology adoption cycle as many products are still "vaporware" that faces major hurdles particularly in the area of data security. However, cloud computing in one form or another will eventually be part of most IT organizations due to its significant cost savings.

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33. Cloud security is an ill-defined, little-understood area of distributed computing. However, gradual progress is being made to provide a level of assurance that accommodates the resources needed to support organisations information processing requirements.

PART VII : CONCLUSION

34. Cloud computing represents an exciting opportunity to bring on-demand applications to customers in an environment of reduced risk(????) and enhanced reliability. However, it is important to understand that existing applications cannot just be unleashed on the cloud as is. Careful attention to design will help ensure a successful deployment. In particular, cloud-based applications should be deployed as virtual appliances so they contain all the components needed to operate, update and manage them. Simple design will aid with scalability as demand for the application increases. And, planning for failure will ensure that the worst doesn’t happen when the inevitable occurs.

35. The environmental benefits of cloud computing is a key driver as many technology companies are going to great lengths to make eco-friendly data centers. As an extreme example, Google was recently awarded a patent for a floating data center that would be located 3 to 7 miles off shore that incorporates wave energy machines to create electricity from ocean waves to power its servers. Whether Google will actually build these floating data centres is debatable, but if Googlers can build a data center in the ocean, why can't the satellite industry build one in space? This is a concept recently presented in form of idea of "Cloud Computing On Orbit" which involves orbit satellites powered by solar energy as space based server farms(Figure above)