The glsldemo textures
were obtained from the USGS web site at
The description and credits for these images are as follows:
Dear User,
This site features a series of consistently processed datasets (land, sea
ice and clouds) from TERRA MODIS and related datasets (topography, land
cover, city lights), all at the 1km resolution. They all originate from processing of
this sensor's data through the years 2000-2001 and originate in the final version
from January 2002. You can find the blue
marble and related files at this site for public download:
It follows a short description of the datasets
All datasets are in the regular lat-lon grid with a grid spacing of
0.008333 degrees per pixel. This projection results in heavy distortion
over the poles, but is suitable for most imaging purposes and needs
least explication to the user. Once mapped onto a globe or reprojected
to a more suitable global map the distortions are no longer visible. The
files are all split into the western and eastern hemisphere with a pixel
dimension 21600x21600 each. This way people using Photoshop can read and
look at the files. Most are in the byte grayscale other in the
interleaved RGB 24bit space, but also some in the signed 16bit integer
data format (I am not sure if photoshop can handle signed integer...?). 
A lot more re-touching could be applied to the blue marble land+ocean
dataset, but considering the time constraints we have for the Olympics
display, I think that this is the best we can provide and I look forward
to hear your comments on the images and on the visualizations that are
going to be made with it. I will render some hi-res globes myself with
the new datasets when I find some time.
When using these datasets please give credits to:
Reto Stöckli, NASA/Goddard Space Flight Center, stockli@cyberlink.ch
Address of correspondance:
Reto Stöckli                    Phone:  +41 (0)1 271 8463
NASA GSFC/ SSAI                 Email:  stockli@cyberlink.ch
Landenbergstr. 16a              Web:    http://visibleearth.nasa.gov
8037 Zürich Switzerland                 http://earthobservatory.nasa.gov
Fritz Hasler and David Herring, NASA/Goddard Space Flight Center
This project was realized under the SSAI subcontract 2101-01-027 (NAS5-01070)
Original data sources
1. Land,ocean,sea ice and clouds: MODIS Atmosphere, Land and Ocean Discipline Groups
2. Antarctica: Pat S. Chavez, Jr., USGS, 2255 N. Gemini Dr., Flagstaff, AZ 86001
3. Topography (Land and ocean): USGS EROS data center
4. Land Cover: UMD 1km Land Cover, Hansen et al. (2000)
5. City lights: World Stable Lights Images - October 1994 to March 1995
   Derived from DMSP OLS Nighttime Imagery, produced at NOAA/NGDC.