Question 1: Free Remote Sensing Imagery/Data.

 There are many websites and government agencies that provide free remote sensing imagery/data.  These data ranges from visible, infrared, LiDar to multispectral data, and could be very useful for research and overall analysis of land cover for a particular area.

a. Earth Explorer

http://edcsns17.cr.usgs.gov/EarthExplorer/

This website is managed by the U.S. Geological Survey, and they are dedicated to providing extensive image data to people with no charge.

This website offers a lot of kinds of data sets  including Aerial Photography, AVHRR, IKONO-2, declassified data, digital elevation data, digital line graphs, digital maps, Land Cover, Landsat etc.

b. USGS

http://www.usgs.gov/

The United States Geological Survey(USGS) was established in 1879. The USGS, as the largest water, earth, and biological science and civilian mapping agency, collects monitors, analyzes and provides very detail scientific and geographic information to people. With the scientific data that they collect, they provides impartial information on the health of our ecosystems and environment, the natural hazards that threaten us, the natural resources we rely on, the impacts of climate and land-use change.

c. GeoGratis

http://geogratis.cgdi.gc.ca/geogratis/en/index.html

GeoGratis provide geospatial data available online for free and without any restrictionl.

GeoGratis is a portal provided by the Earth Sciences Sector (ESS) of Natural Resources Canada (NRCan) which provides geospatial data at no cost and without restrictions via your Web browser.
Due to the fact that GeoGraties website offers not olny a useful a geographic map as a image files but also vector layers of digital data on a classified multiband image, with a digital elevation model as a backdrop.
The geospatial data are grouped in collections and are compatible with the most popular geographic information systems (GIS), with image analysis systems and the graphics applications of editing software.
However, this site only offers only maps of Canada becuase this site is created by Candian Government.

d. NASA Global Change Master Directory (GCMD)

http://www.blogger.com/goog_969775003

The GCMD is one of the largest public metadata inventories in the world. The GCMD’s primary responsibility is to maintain a complete catalog of all NASA’s Earth science data sets and services.  The GCMD has more than 25,000 Earth science data set and service descriptions, which cover subject areas within the Earth and environmental sciences. 
The directory also offers online authoring tools to providers of data and services, facilitating the capability to make their products available to the Earth science community. 

Users can searches through the Directory’s website using controlled keywords, free-text searches, and map/date searches.  Users may also can search map datas by data center, location, instrument, platform, project, or temporal/spatial resolution.








e. Earth Science Data Interface (ESDI) / Global Land Cover Facility (GLCF)http://glcfapp.glcf.umd.edu:8080/esdi/index.jsp

The Earth Science Data Interface is the GLCF's web application for searching, browsing, and downloading map data from Internet for free. The GLCF is a center for land cover science with a focus on research using remotely sensed satellite images and products to assess land cover change for local to global systems.This website provide not only Landsat data with various coordinate systems but also other types of data such as elevation data, MODIS products, AVHRR. This website has very simple and straight-forward map search system, so users will be able to find data they want very easily.

f. GeoBase

http://www.geobase.ca/geobase/en/index.html

 

In Canada, students and researchers are able to access data from GeoBase, overseen by the Canadian Council on Geomatics. The data covers federal, provincial and territorial areas and are up-to-date. Under no cost, the website offer data for geographic regions of the student or researcher’s interest. Next, the data provided are very compatible with modern GIS and Remote Sensing programs. PCI Geomatica is able to utilize these data and provide land cover classification in order to analyze the research subject.