| definition |
- IRIS (Greek goddess of the rainbow and the messenger of the gods). The objective is to provide multispectral imagery in the visible and near-infrared wavelength range. Specific objectives are:
• To demonstrate X-Sat capabilities for remote sensing in the South East Asia region
• To take imagery and collect spatial and radiometric information of land to monitor and manage forests, plantations, urban areas and urban infrastructure
• To detect significant environmental events, such as forest fires, floods and landslides, as quickly as possible and provide timely coverage to monitor the development of these events.
The IRIS camera is being funded by DSO National Laboratories and designed and built by SaTReCi (SaTReC Initiative Co. Ltd. of Daejeon, Korea; SaTReCi is the commercial spin-off from SaTReC), the contractor to NTU. The IRIS instrument is an upgraded version of the KITSAT-3 multispectral imager. IRIS development at SaTReCi was initiated in April 2002. 17) 18)
IRIS consists of an optical and an electronics module. The optical module in turn consists of mirrors, lenses, baffles, detectors, detector front-end electronics, and structural parts. The electronics module consists of the power supply module, control module, and an IRIS-internal mass storage module. IRIS provides also a logical LVDS (Low Voltage Differential Signaling) interface to the PPU (via a RAMDisk) for real-time access to the raw data.
The IRIS instrument design features a pushbroom scanner with three spectral bands: green (520 - 600 nm), red (630 - 690 nm), and NIR (760 - 890 nm). Each of the three linear detector arrays consists of 5000 active elements, which were all manufactured on the same wafer and subsequently coated with different interference filters to select the appropriate spectral characteristic (the FPA houses a quad-linear detector array and the proximity electronics). The design provides a high degree of band-to-band alignment, i.e. 0.1 pixels. The spatial resolution is 10 m GSD (Ground Sample Distance) on a swath of 50 km. The IRIS optics employs a Mangin telescope design with a primary and secondary mirror as well as two correction lenses; the aperture diameter is 120 mm.
Internally the IRIS is equipped with a redundant signal processing and control module (based on a PowerPC architecture) which preprocesses the image data (along with Reed Salomon coding) prior to storage in the 8 Gbit memory module (independent of the RAM-Disk). Access to the image data is through a 50 Mbit/s LVDS link that reads the encoded data from the storage after image acquisition and an 81 Mbit/s link that enables realtime access during imaging.
[Text Source: eorportal.org, http://directory.eoportal.org/]
Group: Instrument_Details
Entry_ID: IRIS-XSAT
Group: Instrument_Identification
Instrument_Category: Earth Remote Sensing Instruments
Instrument_Class: Passive Remote Sensing
Instrument_Type: Photon/Optical Detectors
Instrument_Subtype: Cameras
Short_Name: IRIS-XSAT
Long_Name: IRIS on X-Sat
End_Group
Group: Associated_Platforms
Short_Name: X-SAT
End_Group
Group: Spectral_Frequency_Information
Wavelength_Keyword: Visible
Spectral_Frequency_Coverage_Range: 0.52 micrometers - 0.60 micrometers
End_Group
Group: Spectral_Frequency_Information
Wavelength_Keyword: Visible
Spectral_Frequency_Coverage_Range: 0.63 micrometers - 0.69 micrometers
End_Group
Group: Spectral_Frequency_Information
Wavelength_Keyword: Near Infrared
Spectral_Frequency_Coverage_Range: 0.76 micrometers - 0.89 micrometers
End_Group
Online_Resource: http://directory.eoportal.org/presentations/7105/8557.html
Online_Resource: http://www.dso.org.sg/home/index.aspx
Sample_Image: http://directory.eoportal.org/presentations/7105/XSAT_Auto5.jpeg
Creation_Date: 2008-07-07
Group: Instrument_Logistics
Instrument_Owner: CREST, NTU (Nanyang Technological University), DSO National Laboratories, Singapore
End_Group
End_Group
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