This document discusses using satellite imagery to detect fish farm locations. It describes what satellite imagery and remote sensing are, and provides a brief history of their use in fisheries research since 1960. The document outlines that multispectral images can distinguish water from vegetation, while panchromatic images have higher resolution but do not differentiate as well. It also explains that merging image types can help identify farm ponds. The document estimates that remote sensing methods can detect farm locations at a lower cost than traditional surveys. Finally, it notes some problems with satellite imagery like atmospheric influences and issues with availability.

1. Detection of Fish Farm Location Using Satellite
Image
Presented by
Degonto Islam
Department of Fisheries & Marine
science,
Noakhali Science & Technology
University

2. What is satellite imagery?
• Satellite imagery (also Earth observation
imagery or space borne photography)
are images of Earth or other planets collected
by imaging satellites operated by governments and
businesses around the world.
Shrimp Farming in Honduras

3. What is remote sensing?
• Remote sensing is the science of obtaining
information about objects or areas from a
distance, typically from aircraft or satellites.

4. History
• 1960- The first visible and infrared images technique
use for fisheries research, management and
exploitation.
• 1982- Gower provide a useful overview of the
different kinds of remote sensing data relevant to
fisheries science and oceanography.
• Yamanaka gives examples of some uses of satellite
data for fisheries applications off japan.

5. Types of satellite image used in
locating Aquaculture farm
• Panchromatic (IRS 1D)
• black and white, images have a
high-resolution (6x6
• m) but do not easily distinguish
water from vegetation.
• Multi-spectral (SPOT)
colour images, have a lower resolution
(20x20 m) but
do easily distinguish water from
vegetation through multi-band
properties

6. • It is difficult to use one image to separate water from other
wet areas such as irrigated rice, moist soils, wetlands and
canals.
• But cropping patterns have a distinct seasonal variation and
by comparing two images of different dates, water can be
separated from other wet areas as illustrated in next slide.
• The method is guided by the “two times hit” principle: All
areas (or pixels in the images) that are classified as NEFISCO-
EGIS TRAINING FISH-GIS, November 2000, second version
"wet" in December images as well as in March images are
considered to be "real water".
• All other combinations are classified as floodplains that have
dried, rice fields in which irrigation has started, or dry crops.

7. Distinguish farm area from other wet
area?
Pilot Project (CPP, Tangail)

8. Merging of a multi spectrum image
Figure presents a multi-spectral (A), a high-resolution black and
white (B), and a
merged image (C) in next slide of part of the study area. The
advantage of merging two types of satellite images becomes clear
when looking at the ponds. In the multi -spectra
colour image (A) water is visible as bluish areas but no clear shapes
are visible.

9. Merging of a multi spectrum image
• In the high resolution black and white image (B) in previous
slide, ponds are visible as deep black
• rectangular shapes. In the merged image (C) some of the
ponds become red indicating that they are not ponds but
agriculture plots.

10. How to detect location

11. Cost estimation for detecting farm
Item Cost per km2
Field staff days 7
Transport 4
Small equipment 4
GPS hiring (days) 16
Co-ordination 5
Data entry 5
Total cost 40
Cost of a traditional pond survey

12. Cost estimation for detecting farm
• To compare the costs of the remote sensing-
based methodology with the cost of a
• traditional survey, a comparison was made on the
cost per square kilometre (Table 1 Cost of a
traditional pond survey
• and (Table 2 cost estimation for detecting ponds
using six band composite satellite image ). The
remote sensing method costs 9.45 US$/km2
while a traditional survey costs 40 US$/km2.

13. Cost estimation for detecting farm

14. Problem associated with satellite
imagery
• Application of satellite data ultimately limited by
data availability
• Satellite receive electromagnetic radiation which
emitted from the surface and back scattered
from below the surface. This signals:
Influence by absorption, emission, and scatter by
atmospheric particulate and molecules
Contaminated by reflections from the surface and
clouds
• Sunlight and limb darkening are avoided by
constraining the viewing geometry of the sensor.

15. Importance
• Sustainable aquaculture
• Facilitate resource allocation
• Aquaculture and development
• For potential expansion of aquaculture site
• Provide a visual assessment of site conditions.
• Suitable detailed project planning
• Reduce environmental and social impact

16. Reference
• An introduction to the GIS and remote
sensing in Fisheries Monitoring analysis and
Management, Fish-GIS, A manual (
by…..Gertjan dee Graaf)
• Remote sensing techniques for fisheries
oceanography , T.R. MULLIGAN, & J. F. R.
GOWER

17. Anyquestions