881
Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986
Spatial resolution requirements for urban land cover mapping
from space
William J.Todd
Lockheed Missiles & Space Company, Sunnyvale, Calif., USA
Robert C.Wrigley
Ames Research Center, National Aeronautics & Space Administration (NASA), Moffett Field, Calif, USA
ABSTRACT: Very low resolution (VLR) satellite data (Advanced Very High Resolution Radiometer, DMSP
Operational Linescan System), low resolution (LR) data (Landsat MSS), medium resolution (MR) data (Landsat
TM), and high resolution (HR) satellite data (Spot HRV, Large Format Camera) were evaluated and compared for
interpretability at differing spatial resolutions. VLR data (500 m - 1.0 km) is useful for Level 1
(urban/rural distinction) mapping at 1:1,000,000 scale. Feature tone/color is utilized to distingish
generalized urban land cover using LR data (80 m) for 1:250,000 scale mapping. Advancing to MR data (30 m)
and 1:100,000 scale mapping, confidence in land cover mapping is greatly increased, owing to the element of
texture/pattern which is now evident in the imagery. Shape and shadow contribute to detailed Level I I/I 11
urban land use mapping possible if the interpreter can use HR (10-15 m) satellite data; mapping scales can be
1:25,000 - 1:50,000.
1 INTRODUCTION
The payloads of earth resources satellites offer
great potential for urban mapping, but data is now
available in a wide range of spatial resolutions —
ranging from 10 m to 1.1 km -- and may or may not be
suitable for a particular application. Our
objective was to examine data from a wide range of
resolutions to evaluate interpretability of urban
land cover and derive a set of spatial resolution
requirements for urban land cover mapping.
2 ANALYSIS OF DATA COLLECTED FROM SPACE OVER URBAN
AREAS
The example data which we compared is shown
graphically in Figure 1. Very low resolution data
was collected by the Advanced Very High Resolution
Radiometer (AVHRR) with 1.1 km resolution carried on
NOAA's TIROS satellite, Coastal Zone Color Scanner
(CZCS) with 800 m resolution on NASA's Nimbus-7,
Operational Linescan System (0LS) with 600 m
resolution on the Defense Meteorological Satellite
Program's (DMSP) Block 5D, and the Heat Capacity
Figure 1. Spatial resolution and electromagnetic
spectrum characteristics of selected satellite
sensors useful for mapping urban areas.
Mapping Radiometer (HCMR) with 500 m resolution,
part of NASA's Heat Capacity Mapping Mission. While
Nimbus-7‘s Scanning Multichannel Microwave
Radiometer (SMMR) has spatial resolution measured in
tens of kilometers and did not deserve discussion in
this paper, it is included on the chart as an
example of a passive microwave sensor.
Low resolution data is represented by the 80 m
resolution Multispectral Scanner (MSS), which has
been carried on all five of NASA's Landsat
satellites. Medium resolution data includes the
Landsat-3 Return Beam Vidicon (RBV) 40 m resolution
imagery, and Landsat-4 and -5 Thematic Mapper 30 m
resolution multispectral data.
Figure 2. Digitally enhanced AVHRR thermal infrared
image (Band 4, 10,300-11,300 nm) of central and
southern California collected on August 17, 1984.
The San Francisco-Oakland-San Jose metropolitan area
is in the upper part of the 1.1 km resolution image,
and Los Angeles the lower section.
