ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is an imaging instrument that is flying on Terra, a satellite launched in December 1999 as part of NASA's Earth Observing System (EOS). ASTER is a cooperative effort between NASA and Japan's Ministry of Economy, Trade and Industry (METI) and the Earth Remote Sensing Data Analysis Center (ERSDAC). ASTER will be used to obtain detailed maps of land surface temperature, emissivity, reflectance and elevation. The EOS platforms are part of NASA's Earth Science Enterprise, whose goal is to obtain a better understanding of the interactions between the biosphere, hydrosphere, lithosphere and atmosphere.
ASTER Imagery Examples:
- Okanagan Mountain Park fire, Nearly 3200 people were ordered from their homes today in the Kelowna area as winds kicked up the huge Okanagan Mountain Park fire in British Columbia. The huge fire, which now covers almost 23,000 hectares, destroyed 238 homes on the southern outskirts of Kelowna about two weeks ago. At one point, nearly 30,000 people were forced out, about one-third of the city’s population. The ASTER image covers an area of 51.5 x 53.8 km, and was acquired September 2, 2003. The image is a simulated true color composite, with the active fires highlighted in red from ASTER’s infrared bands.
- Berlin is the capital and the biggest city of Germany. It has a population of about 3.5 million and extends over 889 square kilometers. It is located in central Europe, at the rivers Spree and Havel. Berlin was the capital of Prussia until 1945 and the capital of Germany between 1871 and 1945 and again since the reunification of Germany on October 3, 1990. Between 1949 and 1990, it was divided into East Berlin, the capital of the German Democratic Republic, and West Berlin. It was divided by the Berlin Wall (yellow line on image) between August 13, 1961, and November 9, 1989. This simulated natural color ASTER image covers an area of 22.5 x 20.2 km, and was acquired August 22, 2002.
- Baghdad, Iraq: The plumes, which originate along major roads and canals, are believed to be burning pools of oil from pipelines. The plumes, which blanket large sections of the city of approximately 5 million, are creating an environmental health hazard for residents of the city and surrounding regions. The image covers an area of 44 by 46 kilometers (27 by 29 miles) at a spatial resolution of 15 meters (49.2 feet). ASTER's broad spectral coverage and high spectral resolution are ideally suited for monitoring dynamic environmental conditions caused by natural and human-induced factors.
- London, England: For almost 2,000 years, the River Thames has served as the life force of London, capital of the United Kingdom and one of the world’s most famous cities. In AD 43 the Romans established the trading settlement of Londinium at a favorable crossing point on the river. The Romans remained until the 5th century, when the city came under Saxon control. The early 17th century saw enormous growth, but the deadly plague of 1664 and 1665 ravaged the population, and in the following year the Great Fire, which burned for four days, destroyed most of the city. A public transportation system and other city services in the early 19th century eased many of the increasing urban problems of the burgeoning capital of the wealthy British Empire. After coping with the devastating effects of bombing during World War II and the gradual dismantling of the empire, London today thrives as a vital modern metropolis. London is one of 100 cities being studied using ASTER data to map and monitor urban use patterns and growth. This image covers an area of 55.3 x 39.5 km, and was acquired on October 12, 2001.
Spatial Mapping offers over 2500 Landsat 7 scenes covering most of the North America, South America, Australia and the Mid-East dating from 1999 to the present. Delivery options include custom band combinations, projections, file formats and mosaics.
Different band combinations produce completely different images that highlight the particular features the client is interested in.
Bands 3,2,1 (Red, Green, Blue) combine to form a 'true' colour image that simulates what an observer would see from an airplane.
Bands 5,4,3 (MIR, NIR, Red) combine to a 'false' colour image that highlight the differences between vegetated and non-vegetated areas.
IHS Fuse of Bands 5,4,3 (MIR, NIR, Red) can be used to incorporate Band 8 (15 meter Panchromatic) with the 'false' colour image thereby resulting in a 15 meter resolution colour image.
LANDSAT ETM+ scenes contain 8 different bands of data:
- Band 1: 0.45-0.52 micrometres (blue) 30 metre
- Band 2: 0.52-0.60 micrometres (green) 30 metre
- Band 3: 0.63-0.69 micrometres (red) 30 metre
- Band 4: 0.76-0.90 micrometres (near-infrared) 30 metre
- Band 5: 1.55-1.75 micrometres (mid-infrared) 30 metre
- Band 6: 10.5-12.5 micrometres (thermal infrared) 30 metre
- Band 7: 2.08-2.35 micrometres (mid-infrared) 30 metre
- Band 8: 0.52-0.90 micrometres (panchromatic) 15 metre
Repeat coverage interval: 16 days (233 orbits)
Altitude: 705 kilometers
Quantization: Best 8 of 9 bits (256 grey levels)
IRS Pan data is acquired over the visible green to near infrared portion of the spectrum, and has 5.8 metre spatial resolution. However, compared to SPOT Pan data, which has 256 grey levels, IRS Pan has only 64 grey levels. Therefore, the increased spatial resolution of the IRS imagery has to be balanced against the better depth of SPOT data. Generally, IRS data is fine in lower latitudes.
SPOT 4 data has 10 metre panchromatic and 3 band 20 metre mulitspectral imagery, with scene sizes of 60km by 60km. SPOT data has a higher bit depth than IRS data (8 bit data compared to 6-bit data of IRS), which enables SPOT data to differentiate many of the same forestry related ground features as IRS, even though SPOT has a lower resolution.
SPOT 5 Earth observation satellite was successfully placed into orbit on the 4th of May 2002. It is scheduled to begin collecting commercial imagery in the 3rd quarter of 2002.
Balancing Spatial Resolution and Swath Width
SPOT 5 is the first of the high resolution satellites to truly balance large scene sizes with highly detailed imagery, with coverage of vast territories: scenes of 60 x 60 or 60 x 120 km.
SPOT 5 data are the first source of satellite imagery compatible with regular mapping standards and are an indispensable tool for:
- updating or producing base maps
- 2.5-metre data from Spot 5 are ideal for generating high-quality map products at scales of 1:50 000 up to 1:15 000
SPOT 5 Imagery Examples:
- Stockholm, 2.5 m B&W
- Stockholm, 5 m colour
- Stockholm, 5 m colour, True Colour Enhanced
- Naples, 10 m colour
EROS 1A satellite, which provides 1.8 meter panchromatic imagery, was launched on December 5, 2000. It operates in a sun-synchronous circular orbit at an altitude of 480 km. The EROS satellite weighs 240 kilograms and features a CCD Sensor with more than 7,500 pixels per line. The satellite features an agile push broom sensor which is capable of rotating 45 degrees in any direction. This maneuverability provides efficient use of the satellite resources, resulting in optimized data collection and same-pass stereo collection. Each EROS scene is 12 km square.
EROS data is sold by the square kilometer with the minimum order of 12.5km by 12.5km.
EROS 1A Imagery Examples
- France: Issoudun
- Pentagon: In this image the damage to the Pentagon is clear following the terrorist attack on 11 September 2001.
Spatial Mapping Ltd. uses IKONOS imagery to produce panchromatic images that are radiometrically corrected, geometrically corrected, and orthorectified. Panchromatic and multispectral images are available in easy-to-use 8-bit formats or wide dynamic range 11-bit formats. Applications include base mapping, map revision, GIS update, planning, site selection and development.
IKONOS imagery is offered in 1-meter resolution panchromatic, 4-meter resolution multispectral products and in 1m & 4m bundles.
IKONOS imagery Examples:
- One-meter resolution image of the Bushehr Reactor, Iran.
- One-meter resolution image of Venice, Italy.
- Hainan Island in the South China Sea. A US Navy plane made an emergency landing there after a mid-air collision with a Chinese fighter. The navy aircraft is clearly visible and parked on the taxiway adjacent to the north end of the runway (north is up).
- This one-meter resolution satellite image of Manhattan, New York was collected at 11:43 a.m. EDT on Sept. 12, 2001 by Space Imaging's IKONOS satellite. The image shows an area of white dust and smoke at the location where the 1,350-foot towers of the World Trade Center once stood.
QuickBird data is the highest resolution data commercial available to date. A 0.61 metre panchromatic sensor combined with a 2.44 metre 4 band mulitspectral sensor offer an unprecedented view of the earth. QuickBird data is sold by the square kilometer and has options for different band combinations.
QuickBird Data Examples:
- Mulitspectral Imagery (2.44m)
- Pan Sharpened Multispectral Imagery (0.61m)
- Washington Monument (0.61m)
This product combines up-to-date multispectral Landsat 7 data with high resolution panchromatic orthophotograhpy to produce detailed colour imagery perfectly suited for forestry planning activities.
The image on the left is an example of how Landsat data can be used to apply current information to outdated based data. This images was created from a 1997 (or possibly 1996) TRIM II orthophoto fused with Bands 5,4,3 (MIR, NIR, Red) of Landsat 7 data captured in 2000. You can view the before and after images here.
You can see that in 1997 the road connecting these cutblocks had been constructed, but the cutblocks were cleared sometime after the taking of the orthophoto and before the year 2000, when the Landsat image was collected.