International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004
2. HIGH-RESOLUTION SATELLITE IMAGES (HRS)
A photogrammetric breakthrough has been realised by the
use of space images. The earth observation started with
photographic cameras used for national security reason
(Lavrov, 2000). However, the first digital space camera
system used in space, especially designed for unclassified
mapping purposes was SPOT 1, launched in February 1986.
It was followed by SPOT 2, 3, 4 and others such as IKONOS
and QuickBird. More detailed information on space cameras,
space images and space mapping can be found in Jacobsen
(2001a,b).
The features of the satellites used in the projects subject to
this paper are listed in Table 1. They play a very significant
role as many countries have an intense need for detailed,
accurate satellite imagery for a multitude of important
applications, such as mapping, agricultural monitoring,
resource management and urban planning. A brief discussion
on IKONOS and QuickBird images, GCPs, DEMs and
orthorectification is provided subsequent sections.
Table 1. The main features of HRS used in our projects
sj
1
company Or | first number | mode pixel swath pointing | pointing | height orbit storage
country launch of pixel size [km] in-track | across
(nadir)
Quick Earth 2001 27000 pan 0.61 17 +/-30° +/-30° 450km | inclinat. | 64
Bird 2 Watch multispr 17 52 scenes
6700 4 bands | 2.44
11 bit
lkonos | Space failed 13816 pan 0.82 -|11.3 +-45° | +/-45° 680 sun- 64Gb
active Imaging April 99 multisp. | 2.0 synchr
since EOSAT success | 3454 4 bands | 3.2-8
2000 Sept 99 1 1bit
Resours | Resours 21 | 2001 2000 multisp | 10 205 +/-30° | +/-40° 743 sun 176 Gb
21 5 bands | 20 MIR synchr
SPOT 3 {SPOT 2002 12000 pan 25 30 +/-19.2° | +/-27° 830 sun- 132Gb
Image multisp | 10 synchr
6000 4 bands | 20 MIR | 60
Land- USA since 1 ETM+ 15 185 -- 705 sun- 375Gb
sat 7 April 99 pan synchr
16 multisp | 30
7 bands | 60 TIR
2.1 IKONOS Images
The world's first commercial, high-resolution imaging
satellite has been successfully launched on Sept. 24, 1999
from Vandenberg Air Force Base. The 720 kg IKONOS was
launched into a sun-synchronous, near-polar, circular low-
Earth orbit.
IKONOS is the first commercial imaging satellite of its kind.
It simultaneously collects one-meter resolution black-and-
white (panchromatic) images and four-meter resolution
colour (multispectral) images. Designed to take digital
images of the Earth from 400 miles (680 kilometres) up and
moving at a speed of about four-and-a-half miles (seven
kilometres) per second, the satellite camera can distinguish
objects on the Earth's surface as small as one meter square in
size.
One of the pictures of this satellite belonging to our project
area is shown in Fig. 1.
1029
2.2 QUICKBIRD Images
The QuickBird Satellite was launched on October 18", 2001
at Vandenberg Air Force Base in California. The satellite is
positioned at an Orbit altitude of 450 Km with an orbit
inclination of 97.2°, sun-synchronous.
The QuickBird Satellite sensor provides Panchromatic (P)
Image data at 11 bits with a pixel resolution of 0.61 m at
nadir to 0.72 m at 25° off-nadir and MultiSpectral (MS)
Image data at 11 bits with a pixel resolution of 2.44 m at
nadir to 2.88 m at 25° off-nadir. The swath width of the
QuickBird Satellite is 16.5 km at nadir. Pan sharpened
Natural Color Standard or Ortho Image data is provided with
a pixel resolution of 0.7 m.
The 0.61 m to 0.72 m Pan-sharpened Panchromatic or
Natural Color products can be used for a wide variety of
applications and represents the highest resolution satellite
imagery currently commercially available. The satellite
