In: Wagner W„ Székely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
42 
Nighttime image data from individual orbits meeting pre 
defined quality criteria (i.e. referring to geolocation, sunlight, 
moonlight, cloudiness conditions) form the basis for the annual 
global latitude-longitude grids with 30 arc second resolution 
cells corresponding to approximately 1 km 2 at the equator (see 
Aubrecht et ah, 2008 for more detailed explanations on data 
selection criteria and data composition). 
NOAA’s NGDC stores and maintains the long-term DMSP 
archive (figure 1), and has built up comprehensive experience in 
nighttime image processing and algorithm development related 
to feature identification (e.g. lights and clouds) and data quality 
assessment (cp. Elvidge et ah, 1997; Elvidge et ah, 2001b). 
Dating back to 1992 the data archive enables the production of 
a time series of inter-comparable single-year data sets for 
assessing temporal trends in human activity. Considering the 
entire available digitally preprocessed time series, temporally 
overlapping data from five DMSP satellites are used for inter 
calibration: (1) F-10: 1992-1994, (2) F-12: 1994-1999, (3) F- 
14: 1997-2002, (4) F-15: 2001-2009, (5) F-16: 2004-2009. 
3. SELECTED APPLICATIONS OF MARINE 
ECOSYSTEM MONITORING USING NIGHTTIME 
EARTH OBSERVATION 
In the following sections we present selected applications of 
observing exposure of marine ecosystems to artificial night 
lighting. First, coral reefs are examined on a global scale, 
building up an inventory of stressors (derived from nighttime 
lights data) in close proximity to reef locations. Second, light 
pollution was observed on a more regional scale, comparing 
temporal patterns in sea turtle nesting activity with 
anthropogenic beach lighting development in Florida. Finally, 
this applications selection is concluded with a new study on 
mapping light pollution impact on marine birds on the Azores 
Islands where a ground data collection of light-induced bird fall 
locations serves as actual impact reference information. 
1992 1993 1994 1995 199G 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 
time series (LPI values based on annual nighttime light composites) 
Figure 2. Lights Proximity Index relative change since 1992: 
(1) settlements, (2) fishing boats, (3) gas flares. 
The data was obtained from ‘Reefs at Risk’ (Bryant et ah, 1998) 
and originates from the United Nations Environment 
Programme - World Conservation Monitoring Centre (UNEP- 
WCMC). The initial base data had been converted into raster 
format at a spatial resolution of 1 km. For further spatial 
analyses this grid was (re-)converted into a point dataset. In the 
presented project a list of 330,490 coral reef point locations is 
used where each record is linked with a region classification 
table assigning the reef points to around 150 distinct geographic 
regions worldwide (primarily country-/archipelago-based). 
For a globally consistent assessment of coral reef exposure to 
anthropogenic activities, reef stressors have to be derived from a 
spatially and temporally inter-comparable data source available 
on a global scale. Based on DMSP nighttime lights data, we 
developed an indicator (Lights Proximity Index, LPI), which 
integrates the brightness and distance of lights near known coral 
reef sites. Separate LPI values are calculated for the three 
stressors observable in nighttime lights: (1) human settlements, 
(2) gas flares, and (3) heavily lit fishing boats. The contribution 
of lights to the LPI declines as their distance away from the reef 
site increases. The initial LPI calculation is described in 
Aubrecht et al. (2008). 
Based on the digital nighttime lights data archive a time series 
has been created which enables monitoring of temporal trends 
and detecting areas of improvement and degradation on a 
regional scale. First results of this temporal trend analysis were 
presented by Aubrecht et al. (2009). The current version of the 
LPI time series includes annual composites of nighttime lights 
from DMSP satellites F10 to F16 covering the years 1992 
through 2009. 
3.1 Coral reefs 
A growing body of evidence indicates that artificial sky 
brightness is an important stressor for coral and other marine 
organisms (Jokiel et al., 1985). In addition, satellite 
observations of lighting can be used as a proxy for other 
stressors, such as water pollution from urban areas, fishing and 
recreational use of reefs. 
Coral reef ecosystems are generally found in shallow waters, 
between the Tropic of Capricorn and the Tropic of Cancer. Data 
indicating the spatial distribution of coral reef ecosystems are 
available on a global scale covering a total area of 255,000 km 2 . 
As illustrated by figure 2, results indicate that since 1992 
lighting from human settlements in proximity to coral reefs has 
grown (yellow graph), an indication of the expansion in 
population and infrastructure in coastal areas in many parts of 
the world. In contrast, lit fishing boats activity (blue graph) has 
declined. This may be the result of improved regulation and 
management of reef areas, changes in fishing practices, or the 
depletion of fish stocks that are amenable to capture using 
bright lights. The LPI time series from gas flares (red graph) 
shows a more complex pattern, with dips in 1994 and 2001, a 
peak in 1997, and a largely steady pattern from 2002 through 
2009.