The effect different wetland plant canopies have upon observed reflectance in Thematic Mapper bands is studied. The three major vegetation canopy types (broadleaf, gramineous and leafless) produce unique spectral responses for a similar quantity of live biomass. The spectral biomass estimate of a broadleaf canopy is most similar to the harvest biomass estimate when a broadleaf canopy radiance model is used. All major wetland vegetation species can be identified through TM imagery. Simple regression models are developed equating the vegetation index and the infrared index with biomass. The spectral radiance index largely agreed with harvest biomass estimates

Klemas, V.

English

An area along the southeastern shore of the Chesapeake Bay was subsetted from TM imagery. The subsetted image was then enhanced and classified using an ERDAS 400 system. Results obtained were compared with a chart showing the distribution of both Zolsters marina and Rupplia martime in the Vaucluse Shores and which supports a large community of SAV. Radiative transfer models describing the irradiance reflectance of a water column containing SAV are being refined. Radiative transfer theory was used to model upwelling radiance for an orbiting sensor viewing an estuarine environment. Upwelling radiance was calculated for a clear maritime atmosphere, an optically shallow estuary of either clear or turbid water, and one of three bottom types: vegetation, sand, or mud using TM bands 1, 2, and 3 and MSS bands 4 and 5. A spectral quality index was defined similar to the equation for apparent contrast and used to evaluate the relative effectiveness of TM and MSS bands in detecting submerged vegetation

NASA Technical Reports Server

E 84"" 1001 8
V*
QUARTERLY STATUS AND TECHNICAL
PROGRESS REPORT
Title: Evaluation of Spatial, Radiometric and
Spectral Thematic Mapper Performance
for Coastal Studies
Principal Investigator:
Contract Number:
Dr. V. Klemas
College of Marine Studies
University of Delaware
Newark, Delaware 19716
(302) 738-2336
MAS 5-27580
Technical Monitor: H. Oseroff
Code 902, Building 16, Room 68A
NASA Goddard Space Flight Center
Greenbelt, Maryland 20771
Period Covered: July 1 to September 30, 1983
Ss
G3/43
N84-11555
Unclas
00018
R E C E I V E D
Fl FACILITY
ACCESS DEPT.
https://ntrs.nasa.gov/search.jsp?R=19840003487 2020-03-21T01:44:50+00:00Z
1. Problems
Only one TM image of our Delaware Bay test site was available
(P014, R033, 12/13/82) and due to snow cover it was unsuitable for
marsh vegetation (biomass) studies. To solve the problem one of
our Chesapeake Bay test sites was activated and an available high-
quality TM image ordered (P015, R033, 11/02/82). Due to the delay
in transmitting additional TM data from Landsat 4, four more scenes .
of similar test sites were ordered (P014, R032, 11/27/82 and P012,
R031, 9/10/82). Pictures and tapes for all scenes have been received.
2. Accomplishments
The majority of our most recent efforts have been to modify
our computer software (a version of the Pennsylvania State ORSER
package) to read and analyze CCT-AT and CCT-PT formatted data. This
task is nearing completion and we will have an operational version
of the software within two weeks.
An area along the southeastern shore of Chesapeake Bay was
subsetted from the November 11, 1982 TM image. This area, known
locally as Vaucluse Shores and situated at approximately 37 25'N
latitude, 75 59'W longitude, has historically supported a large
community of SAV. Wetzel (1982) reported a stable seagrass bed
approximately 140 hectares in size and dominated by Zolstera marina
and Ruppia martima. The subsetted TM image was enhanced and classified
using an ERDAS 400 system. The results were compared
with a chart published by Wetzel indicating the distribution of
both Zolstera and Ruppia.
We have continued to refine our radiative transfer models
describing the irradiance reflectance of a water column containing
SAV. These efforts will continue until the spring when we can
conduct field measurements to verify our models.
Radiative transfer theory was used to model upwelling radiance
for an orbiting sensor viewing an estuarine'environment. The
environment was composed of a clear maritime atmosphere, an optically
shallow estuary of either clear or turbid water, and one of three
possible bottom types: vegetation, sand, or mud. Upwelling radiance
was calculated for each case in TM bands 1, 2 and 3 and MSS bands 4
and 5 using data available in the literature. A spectral quality
index was defined similar to the equation for apparent contrast and
was used to evaluate the relative effectiveness of TM and MSS bands
in detecting submerged vegetation.
3. • Significant Results
Computer analysis of the Vaucluse Shores TM image resulted in
a bottom feature classification that correlates well with the
findings of Wetzel (1982). One must keep in mind, however, that
at least 18 months separate Wetzel's measurements and the TM image.
-1-
Disagreements within the classification are most often associated
geographically with a large offshore sand bar. The classification
agrees best with areas reported by Hetzel to be inhabited by Zostera.
Most of the areas indicated by Wetzel to be inhabited by Ruppia
were classified as sand. This is intuitively correct because by
mid-November most of the Ruppia dies back exposing the underlying
sand.
If one considers only the spectral aspect of the problem, the
effectiveness of a sensor to discriminate between submerged features
is determined by the inherent contrast between the features and the
absorbing and scattering properties of the water column and atmos-
phere. In optically shallow water, holding the atmosphere constant,
the inherent contrast between submerged features appeared to be the
most influential factor. As the optical depth of the water increased,
the optimum sensor band for detecting a submerged feature shifted
towards those for which the water was most transparent.
Perhaps the most significant result of this research thus far
is the extent to which it has highlighted the need for optical data
of high spectral resolution. We have become concerned about the
variation in optical characteristics of natural waters and bottom
features across sensor bands. This research has shown, for example,
that under certain conditions the apparent contrast between two
submerged features may decrease to zero at some intermediate depth
and then increase for yet deeper depths. Without detailed knowledge
of the variation in optical properties across sensor bands, this
could not have been predicted.
4. Publications
1) Ackleson, S.G. and V. Klemas. "Assessing Landsat TM and MSS
Data for Detecting Submerged Plant Communities", LANDSAT-4
Early Results Symposium, NASA Goddard Space Flight Center,
February 23-24, 1983.
2) Hardisky, M.A. and V. Klemas. "Remote Sensing of Coastal
Wetlands Biomass Using Thematic Mapper Wavebands", LANDSAT-4
Early Results Symposium, NASA Goddard Space Flight Center,
February 23-2.4, 1983.
5. Recommendations
If no TM data is available for any given test site, investiga-
tors should be encouraged to request TM data for other yet similar
sites, until more data becomes available for the prime site. This
procedure has helped us save much time as far as learning to analyze
TM data and getting good preliminary results.
-2-
7. Data Utility
A project is being developed with State agencies to use
Landsat 4 TM to study the environmental degradation of Delaware's
inland bays (Rehoboth Bay, Indian River Bay, etc.) These bays are
shallow, their shorelines are overdeveloped (e.g. summer homes,
marinas, etc.) and as a result the pollution concentrations are
reaching dangerous levels. The State is proposing to analyze TM
data on our ERDAS system to study turbidity plumes and circulation
patterns in the bays and map changes in vegetation around the bays.
We have found that all major wetland vegetation species can be
clearly discerned in TM imagery. The spatial resolution of TM data
appears to be better than 30 meters, i.e. it seems to be closer to
25 meters than 30 meters.
A significant amount of the submerged grass beds in the Chop-
tank River/Chesapeake Bay are large enough to be resolved in TM
data. In many cases, the number of pixels represented is on the
order of 10. If it is possible to differentiate between submerged
vegetation and other submerged features as well as water features,
TM data would become quite valuable for inventorying submerged
plants. At the present time, this is done by aircraft and aerial
photography and in many cases is prohibitively expensive.


Evaluation of spatial, radiometric and spectral thematic mapper performance for coastal studies

The effect different wetland plant canopies have upon observed reflectance in Thematic Mapper bands is examined. The three major vegetation canopy types (broadleaf, gramineous and leafless) produce unique spectral responses for a similar quantity of live biomass. Biomass estimates computed from spectral data were most similar to biomass estimates determined from harvest data when models developed for a specific canopy were used. Precise determination of regression coefficients for each canopy type and modeling changes in the coefficients with various combinations of canopy types are being tested. The multispectral band scanner vegetation index estimates are very similar to the vegetation index estimates

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furnished in this condition by the organizational source and is the best copy 
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(;Y,
s
r
UARTERLY STATUS AND TECHNICAL
	
e ^qY'-*4
PROGRESS REPORT
Title:
	
Evaluation of Spatial, Radio.11etric
and Spectral ThewatiL 'Iappe.- Performance
for Coastal Studies
Principal Investigator: Dr. V. Klemas
College of 11arine Studies
Universit y of Delav,i-e
Newark, Dela;jare 19716
(302) 451-2336
Contract Nui,rber:	 NAS 5-27580
iechnical Monitor: H. Oseroff
Code 902, 3uildiny io. Rcom C6A
NASA Goddard Space Flight Center
Greenbelt, 'laryland 20771
Period Covered:	 January 1 to ilarch 31, 1924.
(L'84- 10118)	 EVALUAIiUN Of SPATIAL, 	 N84-23978
RAJIUMETRIC AND SPECTRAL THEMATIC MAPPER
Vz;RFOhMAbCE f Oh L OASTAL STUDIES Quarterly
T'ecuuical Status Proyress RtFort, 1 Jan. -
	 UrAclas
31 Isar. 1984 (Deiaware Univ.) 	 5 p	 G3/43 00118
1.	 Problems
i
I
t.
Only one TM image of our Delaware Bay test site was available (PO14,
R033, 12 / 13/82) and due to snow cover, it was unsuitable for marsh
vegetation (biomass) studies. To solve the problem, one of our
Chesapeake Bay test sites was activated and an available high-quality
TM image ordered (PO15, R033, 11/02/82). Due to the delay in trans-
mitting additional TM data from Landsat - 4, four more scenes of similar
test sites were ordered (PO14, R032, 11127182; and P012, 8031,
9/10/82). Pictures and tapes for all scenes have been received and
analysis of the Chesapeake Bay scene has been initiated. We are
eagerly awaiting TM data from Landsat-5. Since our test sites are
more distant than the original ones proposed, and since there are more
of them, we are in the process of requesting a small increase in the
travel and data analysis budgets.
2.	 Accomplishments
The majority or our most recent efforts have been to modify our
computer software (a version of the Pennsyivania State ORSER package)
to read and analyze CCT-AT and CCT-PT formatted data. This task has
been completed and we now have an operational version of the software.
Analysis of ground-gathered Thematic iIapper data is continuing. The
main emphasis of the research was to determine what effect different
wetland plant canopies would have upon observed reflectance in
Thematic Mapper bands. The three major vegetation canopy types
(broadleaf, gramineous and leafless) produce unique spectral responses
for a similar quantity of live biomass. Biomass estimates co ► iputed
from soectral data were most similar to biomass estimates determined
from harvest data when models developed for a specific canopy were
used. In other words, the spectral biomass estimate of a broadleaf
canopy was most similar to the harvest biomass estimate when a broad-
leaf canopy radiance model was used. Work is continuing to more
precisely determine regression coefficients for each canopy type and
to model the change in the coefficients with various co ►hinations of
canopy types. We suspect that textural and spatial considerations
can be used to identify canopy types and improve biomass estimates
from Thematic Mapper data. We expect to test these models when a
summer TM image of the Canary Creek / Great Marsh area becomes available.
As noted in previous progress reports, we have also classified two
subscenes of TM imagery believed to include significant amounts of
Submerged Aquatic Vegetation (SAV). The first image classified was of
Broad Creek, Maryland, just north of the Choptank River. The second
image classified was of Vaucluse Shores / Hungars Creek, located in the
southern portion of Chesapeake, nor^h of the Bay Bridge Tunnel. 	 In
both cases, the classification resulted in moderate success. Hoti,,,ever,
in the Vaucluse Shores image, the classifier frequently misclassified
SAV as deep water and vice versa. We are presently attacking this
problem by including spatial clues within the classification depth.
/iI
We continue to refine our radiative transfer models describing
volume reflectance of eight water columns containing SAV. Although
the modeling efforts are progressing nicely, we hesitate to report
any results until we can get out into the field and verify the model.
We anticipate concluding that phase of the research by the end of
this coming summer.
3. Sianificant Results
A preliminary comparison of Landsat MSS and TM for coastal application
was presented at the Landsat D' Launch User Symposium (see Publication_
section). The results of this comparison are shown in Table 1.
Based on the three morphologic wetland canopy types, simple regression
models were developed equating the vegetation index and the infrared
indc •
 with biomass. Spectral data were collected with the hand-held
radiometer from the ground and from a low altitude aircraft. Sampling
points were arranged on a 30 m grid with actual harvesting of vegeta-
tion conducted after the radiance data were collected. Vlith the vast
majority of spectral radiance index and model cor:,binatio n , the
spectral radiance index estimates of total live biomass r•rere not
significantly different from the harvest biomass estimates. The species
combination models for the vegetation and infrared indices were
particularly good, with the all-species models being the best models
for use with all three spectral radiance indices. The ASS vegetation
index estimates were very similar to the vegetation index estimates.
This is not surprising considering both indices contain essentially
the same spectral information.
We have also found that all major wetland vegetation species can be
clearly discerned in TM imagery. The spatial resolution of TM data
appears to be better than 30 meters, i.e., it seems to be closer to
25 meters than 30 meters.
4. Publications
Ackleson, S. G. and V. Klemas.
	 "Assessing Landsat TM and MSS Data
for Detecting Submerged Plant Communities", Landsat-4 Early
Results Symposium, 14ASA Goddard Space Flight Center,
23-24 February 1983.
Hardisky, H. A. and V. Klemas.
	 "Remote Sensing of Coastal Wetlands
Biomass Using Thematic Mapper 1.4avebands", Landsat-4 Early Results
Symposium, NASA Goddard Space Flight Center, 24-23 February 1984.
Klemas, V. "Comparison of Landsat MSS and TM for ­castal Zone
Applications", Landsat D' Launch User Symposium, Santa Barbara,
CA, 27 February - 1 March 1984.
i
Ackleson, S. G. and V. Klemas. "Remote Reconnaissance of Submerged
Aquatic Vegetation: A Radiative Transfer Approach", Third
Landsat-4 Workshop, NASA Goddard Space Flight Center, Greenbelt,
MD, 6-7 December 1933.
Hardisky, M. A. and V. Klemas. 	 "Aboveground Biomass Estimation In
Tidal Brackish Marsh Using Simulated Thematic -tapper Spectral
Data", NASA Goddard Space Flight Center, Greenbelt, MD,
6-7 December 1933.
	
5.	 Recommendations
All of our quantitative analyses are performed on digital tapes.
Paper prints and transparencies are of great importance for selecting
tapes and planning the digital tape analysis. Therefore, it is more
important for us to obtain the paper prints and transparencies as
early as possible (timely release) than to worry about small density
deviations or scale errors in the film products. The paper prints
and transparencies Qre usually sufficient for planning the processing
of the digital tapes (e.g., test site location identification, cloud-
free area selection, etc.).
Funds Expended
	
7.	 Data Utility
A joint project is being developed with the Haryland Department of
Natural Resources Tidewater Administration to use Landsat TM for moni-
toring environmental changes in estuarine sanctuLries in Chesapeake Bay
The Delaware State Highway Department is interested in using Landsat
data for planning new highway cor r idors. This is an outgrowth of our
work using Landsat data for developing and testing archeological pre-
dictive models, which are able to predict tie potential location of
historic Indian sites with a factor 2 better than any other available
technique.
A project is being developed with Delawe re State agencies to use
Landsat-4 TM to study the environmental degradation of Delaware's
inland bays (Rehoboth Bay, Indian River Bay, etc.). These bays are
shallow, their shorelines are overdeveloped (e.g., summer homes,
marinas, etc.) and, as a result, the pollution concentrations are
reaching dangerous levels. The State is proposing to analyze TM data
on our ERDAS system to study turbidity plumes and circulation patterns
in the bays, and map changes in vegetation around the bays.
TABLE (-
COMPARISON OF LANDSAT MSS
AND TM FOR WASTAL STUDIES
APPLICATION	 IMPROVEMENT
Vegetation and Land Use Medium
Mapping
Biomass Measurement Major
Submerged Aquatic Vegetation Major
Eutrophication Mediuii
Phytoplankton Blooms
Suspended Sediment Currents, Medium
Turbidity Fronts
Pollution	 Plumes Medium
Ocean Dumping
Bathymetry Major
Erosion Control
Ship Traffic f-laj0r
Harbor Planning
Gross Coastal	 Geomorphology Minor
Sargassum Medium
Open Ocean	 Fronts
Internal	 Waves Minor
Sea State


Evaluation of spatial, radiometric and spectral Thematic Mapper performance for coastal studies

General Disclaimer 
One or more of the Following Statements may affect this Document 
 
 This document has been reproduced from the best copy furnished by the 
organizational source. It is being released in the interest of making available as 
much information as possible. 
 
 This document may contain data, which exceeds the sheet parameters. It was 
furnished in this condition by the organizational source and is the best copy 
available. 
 
 This document may contain tone-on-tone or color graphs, charts and/or pictures, 
which have been reproduced in black and white. 
 
 This document is paginated as submitted by the original source. 
 
 Portions of this document are not fully legible due to the historical nature of some 
of the material. However, it is the best reproduction available from the original 
submission. 
 
 
 
 
 
 
 
Produced by the NASA Center for Aerospace Information (CASI) 
https://ntrs.nasa.gov/search.jsp?R=19840019183 2020-03-20T23:00:58+00:00Z
Cs
^o`
J(/1 154
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jaoy -IVI;) y )	 OW 11L+YAIL%00 OF 0P1TiAL6
BADIUBET@IC AUD SPECTRAL TBEMITIC YAPPER
PEBFO,RtlANCE FGR COASTAL STUDIES Quarterly
Status Technical Progress Report, 1 Apr. -
30 Jun. 1984 (Delaware Univ.) 5 p
t,
5 '
I /
N84-272E1
unclas
63/43 U0159
QUARTERLY STATUS AND TECHNICAL
PROGRESS REPORT
Title:
	
Evaluation of Spatial, Radiometric
and Spectral Thematic Mapper Performance
for Coastal Studies
Principal Investigator: Dr. V. Klemas
College of Marine Studies
University of Delaware
Newark, Delaware 19716
(302) 451-2336
Contract Number:
	
NAS 5-27580
Technical Monitor:
	
H. Oseroff
Code 902, Building 16, Room G8A
NASA Goddard Space Flight Center
Greenbelt, Maryland 20771
Period Covered:
	
April 1 to June 30, 1984
	1.	 Problems
We are eagerly awaiting TM data from Landsat-5. Since our test sites
are more distant than the original ones proposed, and since there
are more of them, we are in the process of requesting a small increase
in the travel and data analysis budgets.
Accomplishments
Analysis of ground-gathered Thematic Mapper data is continuing. The
main emphasis of the research was to determine what effect different
wetland plant canopies would have upon observed reflectance in
Thematic Mapper bands. The three major vegetation canopy types
(broadleaf, gramineous and leafless) produce unique spectral responses
for a similar quantity of live biomass. Biomass estimates computed
from spectral data were most similar to biomass estimates determined
from harvest data when models developed for a specific canopy were
used. In other words, the spectral biomass estimate of a broadleaf
canopy was most similar to the harvest biomass estimate when a broad-
leaf canopy radiance model was used. Work is continuing to more
Precisely determine regression coefficients for each canopy type and
to model the change in the coefficients with various combinations of
canopy types. We suspect that textural and spatial considerations
can be used to identify canopy types and improve biomass estimates
from Thematic Mapper data. We expect to test these models when a
summer TM image of the Canary Creek/Great Marsh area becomes available.
As noted in previous progress reports, we have also classified two
subscenes of TM imacery believed to include si gnificant amounts of
Submcrged Aquatic Vegetation (SAV). The first image classified was of
Broad Creek, Maryland, just north of the Choptank River. The second
i mage classified was of Vaucluse Shores/Hungars Creek, located in the
southern portion of Chesapeake, north of the Bay Bridge Tunnel. In
both cases, the classification resulted in moderate success. However,
in the Vaucluse Shores image, the classifier frequently misclassified
SAV as deep water and vice versa. We are presently attacking this
problem by including spatial clues within the classification depth.
We continue to refine our radiative transfer models deszribing
volume reflectance of eight water columns containing SAV. The
modeling efforts are progressing nicely, and we anticipate concluding
that phase of the research by the end of this fall. 	 I
	
3.	 Significant Results
A preliminary comparison of Landsat MSS, TM and simulated SPOT data
for coastal application was presented at four symposia (see Publica-
tions section). Some of the results of this comparison are shown
in Table 1. Basically, the better spatial resolution of TM and SPOT
' _'`^..-. fir.•..-- ^.^ fj-r'.'.^"- \ T
offer major improvement for detecting many features in the coastal
zone which tend to be narrow and long. This includes beds of submerged
aquatic vegetation, submerged sand bars, r)ollution plumes, plots of
marsh vegetation, etc. The Thematic Mapper offers additional improve-
ments due to its superior spectral bands. TM band 1 is particularly
impertant to studies of water properties and submerged features,
while TM band 7 is very sensitive to moisture content of vegetation,
which can be used as an indicator of plant vigor or stress. We have
also found that all major wetland vegetation species can be clearly
discerned in TM imagery. The spatial resolution of TM data appears
to be better than 30 meters, i.e., it seems to be closer to 25 meters
than 30 meters.
Based on the three morphologic wetland canopy types, simple regression
models were developed equating the vegetation index and the tafrared
index with biomass. SpEctral data were collected with the hand-held
radiometer from the ground and from a low altitude aircraft. Sampling
points were arranged on a 30 m grid with actual harvesting of vegeta-
tion conducted after the radiance data were collected. With the vast
majority of spectral radiance index and model combinations, the spectral
radiance index estimates of total live biomass were not significantly
different from the harvest biomass estimates. The species combination
models for the vegetation and infrared indices were particularly good,
with the all-species models being the best models for use with all
three spectral radiance indices. The MSS vegetation index estimates
were very similar to the vegetation index estimates. This is not
surprising considering both indices contain essentially the same
spectral information.
4.	 Publications
Ackleson, S. G. and V. Klemas. "Assessing Landsat TM and MSS Data
for Detecting Submerged Plant Communities", Landsat-4 Early
Results Symposium, NASA Goddard Space Flight Center,
23-24 February 1983.
Hardisky, M. A. and V. Klemas. "Remote Sensing of Coastal Wetlands
Biomass Using Themat". -..*i" oer Wavebands", Landsat-4 Early Results
Symposium, NASA Goddard Space Flight Center, 24-23 February 1984.
Klemas, V. "Comparison of Landsat MSS and TM for Coastal Zone
Applications
	
Landsat D' Launch User Symposium, Santa Barbara,
CA, 27 February - 1 March 1984.
Ackleson, S. G. and V. Klemas. "Remote Reconnaissance of
Aquatic Vegetation: A Radiative Transfer Approach",
Landsat-4 Workshop, NASA Goddard Space Flight Center,
MD, 6-7 December 1983.
.+- . ,.Wf. " -at"
Submerged
Third
Greenbelt,
-	
- 
_. . . -	 _-
Hardisky, M. A. and V. Klemas. "Aboveground Biomass Estimation In a
Tidal Brackish Marsh Using Simulated Thematic Mapper Spectral
Data", NASA Goddard Space Flight Center, Greenbelt, MD,
6-7 December 1983.
Klemas, V. "The Use of Remote Sensing in Estuarine and Coastal
Resources Management", NOAA Environmental Satellite User
Symposium, Washington, DC, 26-28 March 1984.
Klemas, V. "Remote Sensing of Coastal and Ocean Properties", SPIE -
International Society for Optical Engineering Technical Symposium
East '84, Washington, DC, 29 April - 4 May, 1984.
Ackleson, S, G., V. Klemas, H. L. McKim, and C. J. Merry.	 "A
Comparison of SPOT Simulator Data with Landsat MSS Imagery for
Delineating Water Masses in Delaware Bay, Broadkill River, and
Adjacent Wetlands, 1984 SPOT Symposium, Scottsdale, AZ, 20-23
May 1984.
5. Recommendations
More rapiu delivery of Landsat-5 Thematic Mapper data to investigators!
6. Funds Expended
Approximately $40,000 have been expended durinq the first fifteen
months of the contract.
7. Data Utility
A joint project is being developed with the Maryland Department of
Natural Resources Tidewater Administration to use Landsat TM for moni-
toring environmental changes in estuarine sanctuaries in Chesapeake Bay
The Delaware State Highway Department is interested in using Landsat
data for planning new highway corridors. This is an outgrowth of our
work using Landsat data for developing and testing archeological pre-
dictive models, which are able to predict the potential location of
historic Indian sites with a factor 2 better than any other available
technic^^.
A , eject is being developed with Delaware State agencies to use
Landsat-4 TM to study the environmental degradation of Delaware's
inland bays (Rehoboth Bay, Indian River Bay, etc.). These bays are
shallow, their shorelines are overdeveloped (e.g.. summer homes,
marinas, etc.) and, as a result, the pollution concentrations are
reaching dangerous levels. The State is proposing to analyze TM
data on our ERDAS system to study turbidity plumes and circulation
patterns in the bays, and map changes in vegetation around the bays.
w
4
f^
a
3
t'
IMPROVEMENT
Medium
Major
Major
Medium
Medium
Medium
Major
Major
Minor
Medium
Minor
.	 i1
i
d
r
F
f
f
Y	 1
1
j	 I
j
a
.7
TABLE 1.
COMPARISON OF LANDSAT MSS
AND TM FOR COASTAL STUDIES
I
APPLICATION
Vegetation and Land Use
Mapping
Biomass Measurement
Submerged Aquatic Vegetation
Eutrophication
Phytoplankton Blooms
Suspended Sediment Currents,
Turbidity Fronts
Pollution Plumes
Ocean Dumping
Bathymetry
Erosion Control
Ship Traffic
Harbor Planning
Gross Coastal Geomorphology
Sargassum
Open Ocean Fronts
Internal Waves
Sea State


Radiative transfer theory was used to model upwelling radiance for an orbiting sensor viewing an estuarine environment. Radiance was calculated in Tm bands 3,4, and 5 and MSS bands 4 and 5 for an optically shallow estuary of either clear or turbid water, and of three bottom types: vegetation, sand, or mud. A portion of a TM image of Chesapeake Bay was enhanced to obtain a quick look at what submerged features could be detected. The enhancements were compared with low altitude color aerial photography. The TM bands 1,2, and 3 were found to contain water and submerged features information. Band 1 contained a significant amount of noise and low contrast. Band 2 appeared to contain the most amount of bottom information. Band 3, while having the least amount of noise and best constrast, contained a lesser amount of bottom information because of increase water absorption. Several water signatures were identified which correlated with submerged vegetation shown in the aerial photography

General Disclaimer 
One or more of the Following Statements may affect this Document 
 
 This document has been reproduced from the best copy furnished by the 
organizational source. It is being released in the interest of making available as 
much information as possible. 
 
 This document may contain data, which exceeds the sheet parameters. It was 
furnished in this condition by the organizational source and is the best copy 
available. 
 
 This document may contain tone-on-tone or color graphs, charts and/or pictures, 
which have been reproduced in black and white. 
 
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tu► aal W	 QUARTERLY STATUS AND TECHNICAL
PROGRESS REPORT
Title:
	 Evaluation of Spatial, Radiometric and Spectral
Thematic Mapper Performance for Coastal Studies
Principal Investigator: Dr. V. Klemas
College of Marine Studies
University of Delaware
Newark, DE 19711
(302) 738-2336	 19d3
Contract No:	 NAS 5-27580
Technical Monit o r:	 H. Oseroff
Code 902, Bldg. 16, Rm. GSA
NASA Goddard S. F. Center
Greenbelt, MD 20771
Period Covered:	 April I to June 31, 1983
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RAVIOMBiR IC AND SPECIRAL Tht'HAIIC MAPkA-A
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ORIGINAL PAGE pg
1. Problems	 OF POOR QUALITY
Only one TM image of our Delaware Bay test site was available
(P014, R033, 12/13/82) and due to snow-cover it was unsuitable for
marsh vegetation (biomass) studies. To solve the problem one of our
Chesapeake Bay test sites was activated and an available high-quality TM
image ordered (P015, R033, 11/02/82). Due to the delay in transmitting
additional TM data from Landsat 4, two more scenes of adjacent test
sites were ordered (P014, R032, 11/27/82 and P012, R031, 9/10/82).
Pictures and tapes for all scenes have been received.
2. Acomplishments
Radiative transfer theory was used to model upwelling radiance for
an orbiting sensor viewing an estuarine environment. The environment
was composed of a clear maritime atmosphere, an optically shallow
estuary of either clear or turbid water, and one of three possible
bottom types: vegetation, sand, or mud. Upwelling radiance was cal-
culated for each case in TM bands 1, 2, and 3 and MSS bands 4 and 5
using data available in the literature. A spectral quality index was
defined similar to the equation for apparent contrast and was used to
evaluate the relative effectiveness of TM and MSS bands in detecting
submerged vegetation.
A portion of the November 02, 1982 Thematic Mapper image of Chesa-
peake Bay was enhanced using our ERDAS 400 System. The area included
Harris Creek, Broad Creek, and a portion of the Choptank River. The
enhanced im,,ge was compared with low altitude color aerial photography
collected on August 02, 1982. The TM bands were first viewed individ-
ually to determine which ones contained water and submerged features
information. Several three-band combinations were also viewed including
1-2-5, 1-3-5, 2-3-5, and 1-2-3.
During the following months we intend to continue modeling efforts
in order to account for morphological characteristics within the sub-
merged vegetation canopy. The model will be combined with field measure-
ments in the Choptank River area. The results will be compared with
what is found in the November, 1982 image as well as any future images
when data acquisition continues.
3. Significant Result.,
If one considers only the spectral aspect of the problem, the
effectiveness of a sensor to discriminate between submerged features is
determined by the inherent contrast between the features and the absorb-
ing and scattering properties of the water column and atmosphere. In
optically shallow water, holding the atmosphere constant, the inherent
contrast between submerged features appeared to be the most influential
factor. As the optical depth of the water increased, the optimum
sensor band for detecting a submerged feature shifted towards those for
which the water was most transparent.
ORIGINAL PAGE ISj	
OF POOR QUALITY
Perhaps the most significant result of this research thus far is
the extent to which it has highlighted the need for optical data of high
spectral resolution. We have become concerned about the variation in
optical characteristics of natural waters and bottom features across
sensor bands. This research has shown, for example, that under certain
conditions the apparent contrast between two submerged features may
decrease to zero at some intermediate depth and then increase for yet
deeper depths. Without detailed knowledge of the variation in optical
properties across sensor bands, this could not have been predicted.
A portion of the November 02, 1982 Thematic Mapper image was
enhanced using the ERDAS 400 in an attempt to obtain a "quick look" at
what submerged features could be detected. The enhancements were
compared with low altitude color aerial photography collected on August
02, 1982. TM bands 1, 2, and 3 were found to contain water and sub-
merged features information. TM band 1 contained a significant amount
of noise and low contrast. TM band 2 appeared to contain the most
amount of bottom information of the three bands. The contrast in TM
band 2 was better than TM band 1. TM band 3, while having the least
amount of noise and best contrast, contained a lesser amount of bottom
information because of increased water absorption. Of the three-band
combinations investigated, bands 1, 2, and 3 appeared to yield the most
useable submerged features information. Several unique water signatures
were identified which correlated with submerged vegetation shown in the
aerial photography.
4. Publications
1). Ackleson, S. G. and V. Klemas. "Assessing Landsat TM and MSS Data
for Detecting Submerged Plant Communities," LANDSAT-4 Early Results
Symposium, NASA Goddard S. F. C., February 23-24, 1983.
2). Hardisky, M. A. and V. Klemas. "Remote Sensing of Coastal Wetlands
Biomass Using Thematic Mapper Wavebands," LANDSAT-4 Early Results
Symposium, NASA Goddard S. F. C., February 23-24, 1983.
5. Recommendations
If no TM data is available for any given test site, investigators
should be encouraged to request TM data for other yet similar sites,
until more data becomes available for the prime site. This procedure
has helped us save much time as far as learning to analyze TM data and
get good preliminary results.
_I TANAL PAGE 69
OF POOR QUALfTY
Data Utility
All major wetland vegetation species can be clearly discerned in TM
imagery. The spatial resolution of TM data appears to be better than 30
meters, i.e., it seems to be closer to 25 meters than 30 meters.
A significant amount of the submerged grass beds in the Choptank
River/Chesapeake Bay are large enough to be resolved in TM data. In
many cases, the number of pixels represented is on the order of 10. If
it is possible to differentiate between submerged vegetation and other
submerged features as well as water features, TM data would become quite
valuable for inventorying submerged plants. At the present time, this
is done by aircraft and aerial photography and in many cases is pro-
hibitively expensive.


Evaluation of spatial, radiometric and spectral Thematic Mapper performance for coastal studies

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