@ Photonirvachak Journal of the Indian Society of Remote Sensing, Vol. 18, No. 3, 1990, Pages 9-17

A Comparat ive Evaluation of IRS-1A LISS-II and Landsat MSS I m a g e s Using Computer -a ided Lineament Data Analys is

VENKATESH RAGHAVAN AND P.V. PANCHANATHAN

Centre for Earth Science Studies, Trivandrum-695 031

A B S T R A C T

Lineament patterns detected from remotely sensed data provide useful information to geoscientists, specially in the study of basement tectonics, groundwater targetting and mineral exploration. Improvements in the spatial resolution of satellite images have resulted in the detection of short and faint lineaments which have hitherto gone unnoticed The IRS-1A

LISS-II data offers a significant improvement in spatial resolution as compared to the Landsat MSSo A set of computer programmes developed for analysis of lineaments were used to study the parameters such as lineament frequency, length and density in order to quantify the added information der ived using IRS-1A LISS-II images. The incremental contribution

of LISS-II images are of the order of 100 per cent for lineament frequency and about 60 per cent for total line kilometers of lineaments detected.

Introduction

Lineaments demarcated from the satellite images constitute the most easily recognisable parameter of struc- tural and tectonic significance. Improve- ments in spatial resolution of satellite images have resul ted in the identifica- tion of a large number of lineaments which were hitherto not r ecogn i sed on satellite images with poorer spatial resolution. The IRS-1A LISS-II data offers a significant improvement in spatial resolution (36 m) as compared to the LANDSAT MSS images (spatial resolu- tion or 79 m) which have b e e n in use since 1972. In order to evaluate the incremental contribution of IRS-1A

LISS-II images over the LANDSAT MSS, a comparative study was taken up in a test area in central Kerala (Fig. 1). The aim of the study was to use significant parameters such as l ineament frequency, length and density in order to quantify the a d d e d information der ived using IRS-1A LISS-II data. A set of computer programmes deve loped for analysis of l ineaments (Raghavan and Panchanathan, 1989a, 1989b) were used to achieve the above objectives and the results are r epor t ed in this paper ,

Data Used A test area which forms a part of

the southern flank of the 'Palghat Gap' was selected. The area is characterised

10 Raghavan and Panchanathan

by high relief and constitutes a part of the Anamalai hill ranges. The area is devoid of major cultural feature such as highways, railroads, etc. which in many cases may be mistaken as l inea- ments.

and recording the X and Y co-ordinates of l ineament endpoints. These w e r e stored in a computer file to be used as

Fig. 1. Locat/on map of the study area.

Landsat MSS ~1:250,000, Path/Row 077/22 of 27th February, 1973) and IRS- 1A LISS-II (1:125,000, Path/Row 25/61 of 23rd December, 1988). False Colour Composite images were in terpreted and lineaments were identified (Figs. 2 and 3). In o rder to digitise the maps, a cartesian co-ordinate system was esta- blished with the origin at the upper left hand corner of the maps. The X- axis is latitudinal and positive towards right. The Y-axis is meridional and positive downwards. The north was assumed at the top of the maps.

The l ineaments were digitised manually by overlaying the maps on a sheet of graph paper (1 mm spacing)

Fig. 2. Lineament map interpreted from landsat MSS image.

inputs for computer programmes. Since the LISS-II images were on 1:125,000 scale, the digitised l ineament co-ordi- nates de r ived from them were divided by a factor of Lwo in order to have both the maps on a comparable scale.

Fig. 3. Lineament m a p interprefed fror~ IR$- IA LISS-II image.

Compara t i ve Evaluat ion of IRS-1A LISS-II and Landsat MSS 11

Computer Programmes

The summarisation and analysis of digitised lineament data were carried out using a set of computer programmes. A brief description of each of them is given below. The source code for these programmes have b e e n publ ished else- where (Raghavan and Panchanathan, 1989a, 1989b).

Programme Clafy" This reads the end- points of the lineament from the in- put file, The user can def ine an appro- priate scale factor to correct the length in kilometers. The p rogramme catego- rises the lineament data into 18 pre- def ined azimuth classes and output of

the result are obtained in the form of Tables 1 and 2. The output of Clafy pro- gramme was used to create histograms of parameters such as l ineament fre- quency, total length pe r azimuth class and average length pe r azimuth class (Fig. 4).

Programme Roseuty : This is a utility p rogramme which p repares the digi- t ised l ineament data for plotting Rose diagrams. The COGS ROSE (COGS, 1985) programme were used to obtain the plots. Rose diagrams which present the l ineament fabric in a form suitable for qualitative interpretation are p re sen ted in Fig. 5.

Table 1, L ineament da ta for p a r t s of cen t ra l Kera la

b a s e d on Landsa t MSS in te rpre ta t ion .

No. CMIN CMAX FREQ AZLEN AVLEN N% L%

1 2~0.0 280.0 2. 16.4 8.2 6.7 4.6

2 280.0 290.0 0. .0 .0 .0 .0

3 290.0 300.0 1. 15.6 15.6 3.3 4.4

4 300.0 310.0 1. 44,8 44.8 3.3 12.6

5 310.0 320.0 1. 3.0 3.0 3.3 .8

6 320.0 330.0 3. 92.8 30.9 10.0 26.2

7 330.0 340.0 3. 26.0 8.1 10.0 7.3

8 340.0 350.0 2. 24.5 12.2 6.7 6.9

9 350.0 360.0 1. 12.5 12.5 3.3 3.5

10 .0 10.0 0. .0 .0 .0 .0

11 10.0 20.0 1. 9.7 9.7 3.3 2.7

12 20.0 30.0 3. 18.5 6.2 10.0 5.2

13 30.0 40.0 2. 14.4 7.2 6.7 4.1 14 40.0 50.0 1. 5.7 5.7 3.3 1.6

15 50.0 60.0 3, 36.1 12.0 10.0 10.2 16 60.0 70.0 2. 11.6 5.8 6.7 3.3

17 70.0 80.0 3. 17.2 5.7 10.0 4.8

18 80.0 90.0 1. 6.0 6.0 3.3 1,7

Total 30 354.62

(CMIN a n d CMAX a re az imuth c lass m i n i m u m and max imum respec t ive ly ,

AZLEN is total l i n e a m e n t l e n g t h p e r az imuth class , AVLEN is a v e r a g e l inea- men t p e r az imuth c lass , N ~ and L% a re f r e q u e n c y and total l e n g t h in pe r cen t ) .

t

r

Fig . 4.

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Y 4~ 3O

58

b,' k '

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8

7,

6

5

4

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Raghavan and Panchanathan

i

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[- I I I I I I I I I I

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A compara t ive h is togram of s igni6cant p a r a m e t e r s der ived f rom inter- pretation o f MSS and LISS-II images .

14

N

M i

CLASS ~IZE " I01 MAX, RADIAL " 3 r MEDIAN : 188 MEAN : 183J

~OSE PLOI FOR LINEAMENt DATA: PARIS OF CENIRAL

KERALA BASED ON MSS IMAGE

Comparative Evaluation of IRS-1A LISS-II and Landsat MSS 13

cLAss $1~E " I~I MAX, RAI)TAL :

MEAN

~ IIII I ROSE P~I'FOR LINEAMENT DRIft: PARTS OF CENIR~L

KBALA ~$~ ON IRS-IA IMAGE

I I III Fig. 5. Rose diagram for l ineament data from Landsat MSS and IRS.1A LISS-H images.

14 Raghavan and Panchanathan

Contour plot of lineament density (Landsat MSS)

0.00 33.38 66.75 100.13 1.33.50 166.88 200.25 233.63 267.00 I I I l ~ T I JI I l I ] I '1 I I I ' | I l l ] [ -

168,00

134.40

100.80

67.20

33.60

iooo 0.00 33.38 66.75 100.13 133. , .50 166.88 '200.25 233.63 267.00

Fig. 6. L i n e a m e n t dens i t y contours for Landsa t MSS l ineament data using PART option.

201.60

68.00

134,40

100.80

67.20

33,60

0.00

Programme Lineuty : The Lineuty pro- gramme prepares the digitised linea- ment data for contouring, The result ing contour maps illustrate the spatial dis- tribution of l ineament density. Two options are p rov ided to compute the lineament densi ty for every user-de- timed grid cell. The first option (MID) calculates the number of those linea- ments, the midpoints of which fall with- in each grid cell. The second option (PART) considers only that portion of a lineament which falls within each grid cell. The output gene ra ted by the

Lineuty p rogramme can be used by any s tandard contouring software, The lineament density contours for the test area are shown in Figs. 6 and 7.

D i s c u s s i o n s and C o n c l u s i o n s

Interpretations made using LISS-II and MSS data indicate that several short and faint lineaments which were not discriminated on MSS image could be identified on the LISS-II image. Mega- lineaments de tec ted from MSS are com- parable to those detec ted from LISS-II. However, a major E-W trending linea-

Comparative Evaluation of IRS-1A LISS-II and Landsat MSS 15

Conlour plot o f l ineament densi ty (IRS-1A LISS-II)

33.25 66.50 99.7~ 133.00 166.25 199.50 0,00 232.75

' ' / ' ' ' , , ' % ' ' \ ' i

"199.80 10 i

0 . 0 0 l I I 1 I , I I I I I I I I t I I I \ I 1 I I ~ r " I I

266.00

199.80

166.50

133.20

99.90

66.60

33.30

0,00

Fig. 7.

ment in the northern portion of Fig. 3 could be demarcated only in the LISS-II image. Rose diagrams (Fig. 5) indicate major lineament t rends to be ENE-WSW, NW-SE and WNW-ESE. However, the Rose diagram for Landsat MSS data shows a complicated pattern and p r e f e r r ed orientations are not clearly defined. On the other hand, LISS-II data show maxi- mum concentration of l ineaments along ENE-WSW trend and subordinate peaks along WNW-ESE and NW-SE.

Summarisation of lineament data

J 0.00 33.25 66.50 99.75 133.00 166.25 199.50 232.75 266.00

Lineame n t dens i t y contours for I R S - I A L I $ S - I I l ineament da taus ing PART option.

(Tables 1 and 2) indicates that there is an improvement of about 100 per cent in the total lineaments de tec ted using LISS- II images. Thirty lineaments were de-

tected using Landsat MSS whereas sixty

two lineaments were demarcated using

LISS-II. An improvement of about 60 per cent is seen in the total length of linea-

ments identified using LISS-II data. A total of 354 line km of l ineaments were

de tec ted using Landsat MSS whereas interpretation of LISS-II data resul ted in the detection of 580 line km.

16 Raghavan and Panchanathan

The Fig, 4 s h o w s the c o m p a r a t i v e

p i c t u r e of l i n e a m e n t f r e q u e n c y , a v e r a g e

l e n g t h p e r az imuth class a n d total

l e n g t h p e r a z i m u t h c lass of l i n e a m e n t s

i n t e r p r e t e d f r o m b o t h the i m a g e s . A

s ign i f ican t i n c r e a s e in the l i n e a m e n t

f r e q u e n c y is n o t i c e d a l o n g NE-SW to

ENE-WSW d i r e c t i o n for the d a t a p e r -

t a in ing to LISS-II. A n i n c r e a s e in the

l i n e a m e n t f r e q u e n c y a l o n g W N W - E S E

is a lso n o t i c e d . In g e n e r a l , a v e r a g e

l e n g t h of l i n e a m e n t s in v a r i o u s az imuth

c l a s se s is l o w e r in LISS-II data. This

m a y b e a t t r i b u t e d to the d e t e c t i o n of

s h o r t e r l i n e a m e n t s on LISS-II i m a g e s .

T h e total l e n g t h of l i n e a m e n t s p e r azi-

muth c lass is h i g h e r for the LISS-II data .

H o w e v e r the WNW-ESE t r e n d i n g se t s

a r e m o r e p r e d o m i n a n t in the MSS

image . This is a lso r e f l e c t e d in the

a v e r a g e l e n g t h p e r az imuth class.

The c o n t o u r p lo t s of l i n e a m e n t d e n -

si ty u s i n g MSS a n d LISS-II (Figs. 6 a n d 7)

da ta s h o w d i ss imi la r pa t te rn . H o w e v e r

a few z o n e s of h i g h a n d low l i n e a m e n t

d e n s i t i e s a r e c o m p a r a b l e .

Our s t u d i e s on the test a r e a p o i n t

t o w a r d s s ign i f i can t iml~ rovemen t s in

d e t e c t i o n of l i n e a m e n t s u s i n g IRS- IA

LISS-II images . The i n c r e m e n t a l cont r i -

bu t i on of LISS-II i m a g e s a r e of the o r d e r

Table 2. Lineament data for parts of central Kerala based on IRS-1A interpretation.

No. C M I N CMAX' F R E Q A Z L E N AVLEN N% L%

1 270.0 280.0 2. 62.9 31.4 3.2 10.8 2 280.0 290.0 4. 28.6 7.1 6.5 4.9 3 290.0 300.0 3. 40.8 13.6 4.8 7.0 4 300.0 310.0 5. 72.9 14.6 8.1 12.6 5 310.0 320.0 3. 31.5 10.5 4.8 5.4 6 320.0 330.0 3. 21.3 7.1 4.8 3.7 7 330.0 340.0 4. 68.4 17.1 6.5 11.8 8 340.0 350.0 1. 4.6 4.6 1.6 .8 9 350.0 360.0 1. 6.5 6.5 1.6 1.1

10 .0 10.0 1. 10.8 10.8 1.6 1.9 11 10.0 20.0 2. 7.0 3.5 3.2 1.2 12 20.0 30.0 3. 33.9 11.3 4.8 5.2 13 30.0 40.0 3. 36.0 12.0 4.8 6.2 14 40.0 50.0 6. 34.3 5.7 9.7 5.9 15 50.0 60.0 8. 43.1 5.4 12.9 7.4 16 60.0 70.0 8. 53.9 6.7 12.9 9.3 17 70.0 80.0 3. 17.2 5.7 4.8 3.0 18 80.0 90.0 2. 6.6 3.3 3 2 1.1

Total 62 580.35

( CMIN/CMAX in degrees; AZLEN/AVLEN in kilometers ) (CMtN and CMAX are azimuth class minimum and maximum respectively, AZLEN is total lineament length per azimuth class, AVLEN is average lineament per azimuth class, N% and L% are frequency and total length in per cent).

Comparative Evaluation of IRS-1A LISS-II and Landsat MSS 17

of 100 pe r cent for l ineament f requency and about 60 per cent for total line km of l ineaments detected. Variations noticed in the genera l pat tern of the l ineament fabric and densi ty suggest that results based on a single data source n e e d to be v i ewed with caution while making tectonic interpretations. The use of multiple data sources will help r e n d e r interpretations more objec- tive.

Acknowledgements

The authors are thankful to the Director, CESS for permission to publish

the work. The work was done as a part of a research project sponsored by DST, New Delhi.

References

Computer Oriented Geological Society 1985. Program ROSE (Ver. 2.0), IBM-Format Diskette 4o

Raghavan Venkatesh and Panchanathan P.V., 1989a. Fortran-77 Utilities for Lineament Data Analysis. COGS Computer Contrib, 5, (1). 1-15.

Venkatesh Raghavan and Panchanathan P.V., 1989b, Fortran-77 Programmes for Preliminary Summarisation of Lineament Patterns, ]. Ind. Soc.

Rein. Sens., 17, (4) 31-38