especially in case of emergency or also in medium scale
cartographic production, particularly in the zones of difficult
access and in developing countries.
The satellite Ikonos and Geoeye is able to acquire images in
stereopair with two different perspectives, during the same
orbital transit and with a revisit time of 3 days for every point
on the terrestrial surface and it can effect two-way scannings
and acquire up to 7 crawled adjoining strips (each of around
11-13 kms) in a single step.
2. STEREO IMAGES
IKONOS® Pro 1-meter and 4-meter products are perfect for
projects requiring high-resolution imagery and positional
accuracy when ground control may be costly, difficult, or
impossible to acquire.
Providing a strong base for three-dimensional feature
recognition, extraction and exploitation, the product provides
two images with stereo geometry to support a wide range of
stereo imagery applications such as DEM creation and three-
dimensional feature extraction. Stereo products in epipolar or
map projections provide RPC camera model data.
The present study reports on the metric comparison between the
DEMs respectively realized with the Stereo aerial pair and with
the satellite Ikonos stereo pair, and another test with
photogrammetric DEM and a Lidar survey. In a short time we
will compare also GeoEye-1 stereo pair.
The satellite metadata are:
IKONOS METADATA
Sensor Type: Satellite
Sensor Name: IKONOS-2
Processing Level: Standard Geometrically Corrected
Image Type: PAN/MSI
Pan Resolution mt.1.0
MSI Resolution mt 3.28
Interpolation Method: Cubic Convolution
Multispectral Algorithm: Projective
Map Projection: Universal Transverse Mercator
Datum: WGS84
File Format: GeoTIFF
Bits per Pixel per Band: 11 bits per pixel
Multispectral Files: RGB File
Spectral range
Pan 526-929 nm
Blue 445-516 nm
Green 505-595 nm
Red 632-698 nm
Near IR 757-853 nm
Launch date 24-Sep-99
Life Cycle Over 8.5 years
evisit Time — 3 days
Orbital Altitude 681 km
GEOEYE-1 METADATA
Sensor Type: Satellite
Sensor Name: GEOEYE-1
Processing Level: Standard Geometrically Corrected
Image Type: PAN/MSI
Pan Resolution mt.0.50
MSI Resolution mt 1.64
Interpolation Method: Cubic Convolution
Multispectral Algorithm: Projective
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
Map Projection: Universal Transverse Mercator
Datum: WGS84
File Format: GeoTIFF
Bits per Pixel per Band: 11 bits per pixel
Multispectral Files: RGB File
Spectral range
(pan) 450-800 nm
Blue 450-510 nm
Green 510-580 nm
Red 655-690 nm
Near IR 780-920 nm
Launch date ^ 06-Sep-08
Life Cycle 7 years
Revisit Time 3 days
Orbital Altitude 681 km
Figure 1. Test area Ikonos + Aerial
Figure 1 shows the test area, chosen in the Basilicata region for
its characteristics of rockfall area, which was part of the
comparison indicated.
The Ikonos stereo pairs were used for the extraction of DEM by
automatic correlation, with different software (LPS, Socet Set,
Micromap) by geometric parameters of the satellite with the
relevant RPC.
The stereo pairs were obtained using a Wild 15/4 UAGA-F
aerial camera with C=153.22 mm wide frame of about 1: 16000
suitable for cartography at a scale of 1: 5000.
The cartography and its DEM autocorrelation were obtained
using standard procedures of Photogrammetric survey.
