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GLOBAL 1 KM INVENTORY OF HUMAN SETTLEMENTS 
DERIVED FROM DMSP-OLS DATA 
Christopher Elvidge 
Solar-Terrestrial Physics Division 
NOAA National Geophysical Data Center 
325 Broadway, Boulder, Colorado 80303 USA 
Tel. 303-497-6121 Fax: 303-497-6513 
E-mail: cde@ngdc.noaa.gov 
Kimberly E. Baugh 
Cooperative Institute for Research in Environmental Sciences 
University of Colorado, Boulder, Colorado 
Tel. 303-497-6945 Fax 303-497-6513 
E-mail: kbaugh@ngdc.noaa.gov 
Commission VII, Working Group 5 
KEY WORDS: Nighttime lights, human settlements. 
ABSTRACT 
The first 1 km radiance calibrated global inventory of human settlements, derived from low-light 
satellite observations is near completion. The product is being assembled using a 1996-97 time series 
of nighttime visible band observations from the Defense Meteorological Satellite Program (DMSP) 
Operational Linescan System (OLS). Preliminary results indicate that the satellite observed radiances 
are highly correlated to measures of population, economic activity, arid'electric power consumption. 
1. INTRODUCTION 
Much of global change research is dedicated to 
discerning and documenting the impacts of 
human activities on natural systems. Human 
population numbers have expanded from ~750 
million in the mid-1700's to 5.8 billion in 
1996 and are expected to double in the next 45 
years. Human activities which are known to 
be cumulatively altering the global 
environment include greenhouse gas emissions 
from fossil fuel consumption, air and water 
pollution, and land cover / land use change. 
Far from being evenly distributed across the 
land surface, to a great extent human activities 
with environmental consequences are 
concentrated in the vicinity of human 
population centers. As a contribution to global 
environmental research, we are producing a 
satellite data derived map of human 
settlements at 1 km resolution. 
2. MATERIALS AND METHODS 
The DMSP-OLS has a unique capability for 
the global observation of fires and human 
settlements. The primary, function of the 
DMSP-OLS is to provide global imagery of 
cloud cover. At night the observed visible - 
near infrared (VNIR) radiance is intensified, 
for the purpose of cloud detection using 
moonlight. In addition to moonlit clouds, the 
light intensification makes it possible to detect 
VNIR emissions emanating from the earth's 
surface, from cities, towns, industrial sites, gas 
flares, and ephemeral events such as fires and 
lightning. NGDC serves as the nation's long 
term archive for DMSP data. NGDC currently 
receives 7.4 gigabytes of raw DMSP data per 
day using a dedicated T-1 line to the U.S. Air 
Force, Offutt Air Base, Omaha, Nebraska. 
Data transfers occur automatically, as readouts 
are received by Offutt, and arrive on the 
NGDC computer within 1-2 hours from the 
observation time (longest delay comes from 
the time gaps between successive readouts of 
the on-board tape recorders). At NGDC the 
data are deinterleaved and written out to 
archive tapes. Our near-real-time global DMSP 
data stream, ingest, preprocessing, and product 
generation are analogs for EOS-MODIS. It is 
anticipated that the DMSP-OLS data stream 
Intemational Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998