Data Covered in the Topic - Open Source Geospatial Tools: Applications in Earth Observation - page 327

A.1.3 3D Point Data

The web site from the libLAS C/C++ library for reading and writing the LAS LiDAR
format provides a number of sample data. 5 A number of snippets in this topic are
based on the point cloud acquired with an airborne LiDAR sensor over Mount St.
Helens. The data is available in LAS format in the coordinate reference system
NAD83 / UTM zone 10N (EPSG:26910). In Sect. 15.3.1 we convert a subset of the
point cloud to vector format (ESRI Shapefile).
The LiDAR derived products in Sect. 15.4 are based on a point cloud of a forested
area in Belgium. In addition to height information, the data also contain the energy of
the return pulses (intensity). They have been acquired with a full waveform LiDAR
sensor for a research project. 6 The data are converted to discrete pulses in LAS
format and available on our website. 7 The coordinate reference system is Belge
1972 (EPSG:31370).

A.2 Geospatial Raster Datasets

A.2.1 Medium Spatial Resolution Multispectral Data

The moderate resolution imaging spectroradiometer (MODIS) is an instrument
aboard the Terra and Aqua satellites. These twin satellites have overpasses in the
morning and afternoon respectively. Products can be downloaded from the land
processes distributed active archive center (LP DAAC). 8 We have prepared monthly
composites (based on the median value) for all months in 2010 over a region in north-
ern Italy. For each month, we then calculated the normalized difference vegetation
index (NDVI). The result is available as a multiband GeoTIFF image with 12 bands
( modis_ndvi_2010.tif ) and can be downloaded from our website.
Another derivative product from MODIS is the global NASA blue marble image
(Stöckli et al. 2005), available from NASA's website. 9 It is a JPG image that covers
the full globe from

90 (lower right corner) in
21,600 columns and 10,800 lines (check with gdalinfo ). We select a geographical
coordinate systemWGS84 (EPSG:4326) as the target coordinate system, using only
three GCP for the transformation.

− 180 90 (upper left corner) to 180 −

5 http://www.liblas.org/samples/
6 Hyperforest, with thanks to the Belgian science policy office.
7 http://opensourcegeospatialtools.org/data
8 https://lpdaac.usgs.gov/
9 http://visibleearth.nasa.gov/view.php?id=74418