Wahana dan Sensor Penginderaan Jauh

Mega L. Syamsuddin, Ph.DRemote sensing2013

Sub pokok bahasan Wahana & sensor penginderaan jauh Satelit penginderaan jauh

Tujuan Pembelajaran Khusus:

Mahasiswa mampu menjelaskan wahana dan sensor yang digunakan dalam sistem penginderaan jauh

PLATFORM & SENSOR

Sensor adalah alat yang merekam dan mengukur energi elektromagnetik.

Sensor di pasang pada wahana (Platform) dan letaknya jauh dari obyek yang diindera.

Satellite image example:

Platform: Landsat (1, 5, 7 etc..)

Sensor: Multispectral Sensor (MSS) or Thematic Mapper (TM)

ORBIT

Geostationary orbit

Polar orbit

Lintasan Barat-timur Utara-selatanInklinasi 0, di bidang ekuator 90 (+)&(-)Altitude 36000 km 600-1500 kmLiputan Tetap pada posisi tertentu Timur ke baratSifat Geosynchronous (sinkron

thd bumi)Sunsynchronous (sinkron thd matahari)

Ascending and Descending passes

Geostationary orbit Polar orbit

-Weather images: GOES (Geostat. Operational Env. Satellite)

Geostationary

Sun-synchronous

Sensor1. Sensor Aktif: terdiri dari radiometer yang dilengkapi

dengan alat pemancar (u memancarkan gelombang mikro), alat perekam dan monitor; dikembangkan untuk menghilangkan kesalahan citra yang diakibatkan oleh awan dan kabut.

2. Sensor Pasif: dilengkapi dengan alat perekam dan monitor. Sensor ditempatkan di satelit yang secara alami dapat merekam gelombang pantul dan atau hambur dari objek.

ITC, 1999

Sensor groupsMulti-spectral sensors record bands in multiple wavelengths: Visible Near IR Mid IR Thermal Microwave

And at different spatial resolutions: Low Medium High Very high

Satellite remote sensing systems

NASA Visible Earth:

Wim Bakker's website   http://members.home.nl/wim.h.bakker

LANDSAT • Swath Width: 185 km• Repeat Cycle 16 days • Orbit Altitude: 705 km• Equatorial Crossing: at around 10 a.m. local solar time

Spectral Bands of Landsat-7Band Spectral Range (mm) Ground Resolution1 (Blue) .450- .515 302 (Green) .525- .605 303 (Red) .630- .690 304 (Near IR) .750- .900 305 (Mid IR) 1.55- 1.75 306 (Thermal IR) 10.4- 12.5 607 (Mid IR) 2.09- 2.35 30Panchromatic .520-.900 15

USA, 1999

SPOT

Band (m) Spectral range (µm) Spatial resolution (m) B1 (Green) .500 - .590 20 B2 (Red) .610 - .680 10 and 20 B3 (Near IR) .790 - .890 20 SWIR (MIR) 1.58 - 1.75 20

Systeme Pour l’Observation de la Terre (France)

• SPOT-5 (2002)• Swath Width: 60 km• Repeat Cycle 26 days • Orbit Altitude: 832 km

Summary table: Landsat TM versus SPOT HRV (1980s)

  LANDSAT TM SPOT HRV

Launch 1982 / 1984 1986Altitude 705 km 832 kmAttitude (polar) 8.2 degrees 8.7 degreesEquatorial time 10 am 10.30 amSwath width 185km 60km Repeat coverage 16 days 26 days

Sensor  Thematic Mapper (TM)

High Resolution Visible (HRV)

Number of detectors 100 6000/3000

Advantages  #bands, swath size higher resolution, #'looks'Bands 7 1 + 3

IKONOS

USA, September 1999

• Repeat Cycle 1-3 days • Orbit Altitude: 681 km

Band (m) Spectral range (µm) Spatial resolution (m)1 (Blue) 0.45-0.52 4

2 (Green) 0.51-0.60 4 3 (Red) 0.63-0.70 4 4 NIR 0.76-0.85 4 Pan (VNIR) 0.45-0.90 1

Quickbird

USA, 2001

• SPOT-5 (2002)• Swath Width: 16 km• Repeat Cycle 1-4 days • Orbit Altitude: 450 km

Sensor Spectral range (µm) Spatial resolution (m)EBM (Blue) 0.45-0.49 15

EBM (Red) 0.61-0.68 15 EBM (NIR) 0.79-0.89 15 EBP (VNIR) 0.45-0.80 3

GOES (Geostationary Operational Environmental Satellites)

The GOES series of satellites is the primary weather observation platform for the United States.

The latest generation, GOES I-M, represent an advance in data products for weather forecasting and storm warnings over the previous series of geostationary satellites.

GOES I-M is a 3-axis stabilized system vs. the older spin-scan system, providing more accurate geo-location of earth images.

METEOSAT

Europe's geostationary weather observation satellite

Meteosat was launched in November 1993. The 4 channel, 3-spectral-band high resolution

radiometer constitutes the main payload on board Meteosat.

The radiometer scans in 3 spectral bands: Visible, Infrared, and Water Vapor.

The instrument allows continuous imaging of the Earth with images sent every half-hour.

SAR CharacteristicsFrequency / Wavelength 5.3GHz/C-band 5.6 cmRF Bandwidth 11.6, 17.3 or 30.0 MhzTransmitter Power (peak) 5 kWTransmitter Power (average) 300 WMaximum Data Rate 85 Mb/s (recorded) - 105 Mb/s (R/T)Antenna Size 15m x 1.5mAntenna Polarization HH

Orbit Characteristics Altitude 793-821 kilometresInclination 98.6 degreesPeriod 101 minutesAscending node 18:00 hoursSun-synchronous 14 orbits per day

Coverage Access Using Maximum Swath WidthNorth of 70 degrees N DailyNorth of 48 degrees N Every 4 daysThe Whole Earth Every 6 days

RADARSAT Canadian Space Agency

Japanese Satellite and Earth Observation SystemJERS-1

(Japanese Earth Resources Satellite)1. Objective: Gather data on global land masses while conducting observation for land surveys, agricultural-forestry-fisheries, environmental protection, disaster prevention and coastal surveillance, with emphasis on locating natural resources.2. Operation Time : 1992 - 19983. Sensors: • SAR (Synthetic Aperture Radar) which is an active

microwave sensor• OPS (Optical Sensor) that measures light reflected from

the earth's surface ranging from visible light to short-wave infrared light.

• ADEOS (Advanced Earth Observing Satellite)1. Goal: Monitoring global environmental changes such as maritime

meteorological conditions, atmospheric ozone, and gases that promote global warming

2. Operation Time : August 1996 - June 19973. Sensors: • AVNIR (Advanced Visible Near Infrared Radiometer) • OCTS (Ocean Color and Temperature Scanner)• NSCAT (NASA Scatterometer)• TOMS (Total Ozone Mapping Spectrometer)• POLDER (Polarization and Directionality of the Earth's

Reflectance)

• OCTS (Ocean Color and Temperature Scanner) • MOS (Marine Observation Satellite MOS-1 /

MOS-1b)