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Friday, January 14, 2011

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GEOG 4440: Remote Sensing & Image Processing

Assignment 1: Data Description : Metadata and More
Professor: Tarmo Remmel

TA: Yikalo Araya

Student Name : Jinha Bok

Student #: 209216631

Data: January 21, 2011

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.

Question 2: Finding Two Landsat 7 Images

About Landsat 7 :)

Landsat 7 Satellite:

Landsat 7 is a U.S. satellite used to acquire remotely sensed images of the Earth's land surface and surrounding coastal regions. The Landsat 7 satellite was launched in 1999 and was designed to last five years. It continues to function at diminished capacity. The Landsat Data Continuity Mission, scheduled to be launched in 2011, will be the next satellite in the Landsat series. The goal of the Landsat satellite program is to improve our understanding of the Earth as an integrated system, including how it responds to natural and human-induced disturbances. (Heat Island Effect, 2009)

How to get Landsat 7 images

In order to give more detailed information about finding map data. I picked two interested images from GeoGratis(http://geogratis.cgdi.gc.ca/geogratis/en/index.html).

In the "Landsat 7 Level 1-G Imagery over Canada" there are about 1150 index covering all over the area of Canada. In order to get to know about the Landsat 7 image that the site provides, I downloaded both two image files and metadata of those two images (data about data).

Import two maps to PCI Geomatics

It was possible to open TIFF. compressed file with PCI Geometis, however, with this compressed file, it is not able to have all bands (seperate TIFF files of each band). Therefore, we should download all separate band files and make sure that all files are TIFF files. From the two maps of Canada that I downloaded from the GeoGratis site, there were no tiff. file available. So, in order to get the TIFF file, we should get the data as TIFF format from GLCF- esdi website.

http://glcfapp.glcf.umd.edu:8080/esdi/index.jsp

After download the areas of two maps of Canada. In order to extract the GZ. files from the GLCF website, download the Altap Salmander 2.54 from http://www.altap.cz/download.html

Extracting files with Altap Salamander 2.54

How To MERGE ALL SEPERATED BANDS

Go to "PCI Moderler"

From Module Librarian find "Merge", "Import","Export" icons

Drag one merge icon, 6 import icons, and one export icon. (we have six bands to merge)

Question 3: Details of my two maps

Scene: L71007028_02820010826

[Image Production Informaion]

Source:Geomatics

OrderId: 00-00884-269
Satellite: LANDSAT-7
Sensor: ETM+
OrbitSense: 'D'
Input DatasetId = "RSI-2728";
Product Generation Time = "2001 10 07 10:10:16.000";
Output Format = "HDF";

[Image Informaion] Browse Image File Path: .././00-00884-269_
Start Time: 2001 08 26 14:43:33.334
End Time: 2001 08 26 14:43:59.855
Centre Time: 2001 08 26 14:43:41.874

[Locational Informaion]

Centre Location      latitude: 4.603171129914435e+01
      longitude: -6.217700231669508e+01

Corners
      Upper Left
       latitude: 4.699947576763559e+01
       longitude: -6.318641633054710e+01

      Upper Right

        latitude = 4.663566311042554e+01
        longitude = -6.069273787443211e+01

      Lower Right
        latitude = 4.505540635023829e+01
        longitude = -6.120225979416796e+01

      Lower Left
        latitude = 4.540861617205387e+01
        longitude = -6.362894454659147e+01

Product Framing Method: "Path Row"
PATH = 7
ROW = 28
Scene Shift = 0
Product Orientation = "Satellite"
Numer of Lines = 6002L
Number of Pixels = 6484L
Pixel Spacing = 3.000000000000000e+01
Line Spacing = 3.000000000000000e+01
Width = 1.945200000000000e+02
Height = 1.800600000000000e+02

CorrectionLevel = "Systematic Geocorrection"
Map Projection: "UTM";
Zone Number: 20
EarthEllipsoid: NAD83
Resampling Kernel: CC
Elevation Correction: None

[Sensor Information]

Off Nadir Angle = 4.322774128055714e-02;
Sun Azimuth = 1.467131722544012e+02;
Sun Elevation = 5.054643148082491e+01;

Scene: L71019013_01320020801

[Image Production Informaion]
Order ID: 02-01303-033
Station ID: MDA
Satellite: LANDSAT-7
Sensor: ETM+
Orbit Sense: 'D'

Input DatasetId: RSI-4329
Product Generation Time: 2002 09 18 20:19:49.000
OutputMediaType = "CD"
OutputFormat: HDF
Media Interleaving: BSQ

[Image Informaion]
Browse Image File Path = .././02-01303-033_
Start Time: 2002 08 01 15:51:12.751
End Time: 2002 08 01 15:51:39.310
CentreTime: 2002 08 01 15:51:25.995

[Locational Informaioin]    Centre Location      latitude = 6.693539813327550e+01;
      longitude = -6.811795025302996e+01;

    Corners
      upper Left
        latitude = 6.799306174992407e+01;
        longitude = -6.947498051820500e+01;

      Upper Right
        latitude = 6.735222534394103e+01;
        longitude = -6.528201210953019e+01;

      Lower Right
        latitude = 6.586707281769353e+01;
        longitude = -6.687390758133233e+01;

      Lower Left
        latitude = 6.646954780666432e+01;
        longitude = -7.085350707587294e+01;

Product Framing Method: "Path Row"
PATH = 19
ROW = 13
Scene Shift: 0
Product Orientation: Satellite
Number of Lines = 6000L
Number of Pixels = 6386L
Pixel Spacing = 3.000000000000000e+01
Line Spacing = 3.000000000000000e+01
Width = 1.915800000000000e+02
Height: 1.800000000000000e+02
Correction Level: "Systematic Geocorrection"
Map Projection: UTM
Zone Number: 19
Earth Ellipsoid: "NAD83"
Resampling Kernel: "CC"
Elevation Correction: "None";
Base Elevation: 0.000000000000000e+00
Line Spacing: 3.000000000000000e+01
Pixel Spacing: 3.000000000000000e+01
[Sensor Information] Off NadirAngle: 3.138047149186559e-02
Sun Azimuth: 1.651117985737949e+02
Sun Elevation: 4.054566548431400e+01

This matadata is derived from:

http://www.geogratis.gc.ca/download/landsat_7/hdf/

Question 4: Global Locator Map

Global Locator Map

Map of Canada (by Google)

http://itouchmap.com/latlong.html

Geogratis does not tell geographical name of the area in each index, however, by looking at the latitude and longtitude that the description file (productdescription.self) shows we can find the location of the area in each index.

Fortunately, some websites help us to find the location by searching latitude and longitude of a point. The description file tells us lat. & long. of central location and it of four corners. It will be good to use the central location lat. & long. first, when we search the point.

How to find the geographic locale

that your data represent

This index shows east coast of Canada covering parts of Prince Edward Island, Nove Scocia and Newfoundland.

due to the fact that the size of the map data is too big, I cropped the image by remaining just Eastern PEI regions.

This index shows the north-east part of Canada covering Auyuittuq National Park of Canada in Nunavut.

Also, the size of the map is too big to handle in this experiment, I used cropped mat that covers just some part of the Auyuittuq National Park.

Question 5: What I can see

[True & False Colour Images]

[True Colour]

A true-color map is an image that appears to the human eye like the original subject would.

So, green vegetation areas appear as green in the image, the Oceans appear as dark blue, clouds and snow covered areas appears as white, etc. In order to make a true colour image, the three bands that represent red, green, and blue (RGB) in the visible spectrum are combined. Each band is displayed in a monochromatic scale corresponding to its appropriate colour.

http://oceancolor.gsfc.nasa.gov/SeaWiFS/TEACHERS/TrueColor

[False Colour]

In a false-color image, subject color and image color is different. This alternation can be happened in many ways.For example, the near infrared band (band 4 is projected onto colour film through a red filter (R), band 3 through a green filter, and band 2 through a blue filter. In this case, the red coloured area will represent VEGETATION, Black coloured area will represent WATER in false colour image.


REG Mapper

[Greyscale Images]

Grayscale image is an image with black and white colours. All three Red, Green, Blue bands should be chosen together.

IMAGES OF Prince Edward Island

IMAGES Of Auyuittuq National Park of Canada

[NDVI]

the Normalized Difference Vegetation Index (NDVI) was run on both images to analyze the vegetation degree in both locations. During the analysis, the first image shows denser vegetation in the overall area compared to the second Image. The darker the shade of red means that the area is dense in vegetation. Consequently, the lighter the shade of red the less vegetation density there is in the area. If the location is blue, then this means that there is no vegetation, clearly seen in the water bodies in both images.