Spectral calibrations of HICO data using atmospheric bands and radiance adjustment based on HICO and MODIS data comparisons

by on 9 June 2015in Earth Science and Remote Sensing No comment

The Hyperspectral Imager for the Coastal Ocean (HICO™) instrument is now operating from a location on the Japanese Experiment Module-Exposed Facility (JEM-EF) on the International Space Station (ISS). HICO™ is a pushbroom sensor covering a spectral range between 0.35 and 1.08 micron with a spatial resolution of about 90 meter and a spectral sampling interval of 5.7 nanometer. The instrument is not equipped with radiometric and spectral calibration devices. Before shipping the HICO™ instrument to Japan to be launched on a Japanese HII-B rocket, spatial, spectral, and radiometric calibrations of the instrument were made in a calibration lab at the Naval Research Laboratory in Washington, DC. Based on the analysis of HICO data acquired from ISS/ we have observed that the wavelengths of the HICO channels are slightly changed in comparison with those from laboratory calibrations. We have used a spectrum matching technique [2] for adjusting wavelengths. Several atmospheric water vapor and oxygen absorption bands in the HICO data measured under the normal operation mode with a spectral sampling interval of approximately 5.7 nm are used for spectrum matching. Four extra-terrestrial solar lines in the HICO data with a spectral spacing of 1.7 nm are also used for spectrum matching. The spectrum matching technique is described in this paper. Also based on analysis of ISS HICO data, we have found that the radiances of ISS HICO data calibrated with the laboratory-based coefficients are smaller than expected by approximately 25%. We have adjusted the calibration coefficients based on comparing HICO data and MODIS data acquired over several desert areas. The vicarious calibration procedure for HICO radiometric calibrations is also described in this paper.

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Assessing water quality in the northern Adriatic Sea from HICO (TM) data

by on 9 June 2015in Earth Science and Remote Sensing No comment

This letter focuses on water-quality estimation in the northern Adriatic Sea using physically-based methods applied to image obtained with the Hyperspectral Imager for the Coastal Ocean (HICO). Optical properties of atmosphere and water were synchronously measured to parameterise such methods. HICO-derived maps of chlorophyll-a (chl-a) and suspended particulate matter (SPM) indicated low values, in the range of 0-3mgm(-3) and 0-4gm(-3), respectively, correlating significantly with field data (R-2=0.71 for chl-a and R-2=0.85 for SPM). The results, on analysis, identify clear waters in the open sea and moderately turbid waters near the coast due to river sediment discharge and organic matter from coastal lagoons. These findings support the use of HICO data to assess water-quality parameters in coastal zones and suggest the feasibility of integrating them with future-generation space-borne hyperspectral images.

Related URLs:
<Go to ISI>://WOS:000324724800011
http://www.tandfonline.com/doi/abs/10.1080/2150704X.2013.830203

Columbus-External Payload Facility (Columbus-EPF)

by on 2 May 2015in Earth Science and Remote Sensing
  • External payload platform
  • 4 payload sites (1 Zenith, 1 Nadir, 2 Starboard)
  • Mass per payload 290kg
  • Power capability of 1.25 kW is provided by two 120-Vdc redundant power feeds at each attachment site
  • Maximum payload size 864 x 1168 x 1245 mm without the adapter plate

Data capabilities:

  • Low-rate 1553-B data line for status data
  • Medium-rate Ethernet data line with rates of up to 1.55 Mbps
  • High-rate data line interfaces with the video data processing unit and transmits up to 32.426 Mbps in increments of 32 kbps

Lightning Imager Sensor (LIS)

by on 2 May 2015in Earth Science and Remote Sensing
  • One of the Space Test Program (STP-H5) instruments
  • Field of View (FOV): 80 degrees x 80 degrees
  • Pixel Instantaneous FOV (IFOV): 4 km
  • Measurement Accuracy
    • Location: 1 pixel
    • Intensity: 10%
    • Time: Tag at frame rate
  • Interference filter
    • Wavelength 777.4 nm
    • Bandwidth 1 nm
  • Detection threshold 4.7 µJ m-2 sr-1
  • CCD array size 128 x 128 pixels
  • Dynamic range >100
  • Detection efficiency ~90%
  • False event rate <5%
  • Dimensions
    • Sensor head assembly 20 x 37 cm
    • Electronics box 31 x 22 x 27 cm
  • Instrument mass 20 kg
  • Instrument power 30 W
  • SNR (Signal to Noise Ratio) 6
  • Telemetry data rate 8 kbit/s
  • Telemetry format PCM (Pulse Code Modulation)

ISS-RapidScat

by on 2 May 2015in Earth Science and Remote Sensing

Specifications

Instrument

  • SeaWinds Scatterometer (Pencil Beam Scatterometer)
  • Antenna Diameter: 0.75 m
  • Mounted on Columbus Module

System Parameters (courtesy of NASA’s JPL)

  • Orbital Attitude : 435km
  • Antenna Size: 0.75m
  • 3 dB beamwidth – 1 way – elevation: 2.4, 2.2 degree
  • 3 dB beamwidth – 1 way – azimuth: 2.1 degree
  • Antenna Rotation Rate: 18rpm
  • Operating Frequency: 13.4 GHz
  • Chirp Rate: 250 kHz/ms
  • Pulse Width: 1.0 ms
  • PRI: 6.0 ms
  • Peak Radiated Power: 80 W
  • Incidence Angle, 2 Beams: 49.56 degree
  • Ground-range Resolution: 0.79, 0.73 km
  • Azimuth Resolution: 15.5, 17.3 km
  • Slant Range: 600, 678 km
  • Ground Swath: 900, 1100 km
  • Data Window Length: 1.4 ms
  • NE sigma0: -32.8, -31.5 dB

Cloud-Aerosol Transport System (CATS)

by on 2 May 2015in Earth Science and Remote Sensing

Specifications

  • CATS operates in three different modes.  Mode 1 is the primary operating mode; Modes 2 and 3 are used periodically.

Sensor

  • Light detection and ranging (LiDAR)

Spectral Bands

  • Operational Mode 1: Multi-beam mode splits the energy from the first laser into two wavelengths that represent near infrared radiation (1064 nanometers) and visible light (532 nanometers) for determining layer type (i.e., cloud and aerosol composition).
  • Operational Mode 2: Uses the second laser and to demonstrate a new technology called High Spectral Resolution Lidar (HSRL). This new technique uses a narrower wavelength interval at 1064 and 532 nanometers to provide more precise measurements. The will provide better estimates of extinction, which is extremely important for model applications since it is an important variable in determining the radiative effects of clouds and aerosols on the climate system.
  • Operational Mode 3: Uses the second laser, in addition to operating at 1064 and 532 nanometers, adds a third wavelength at 355 nanometers. The shorter wavelength of 355 nanometers lies in the ultraviolet region of the electromagnetic spectrum and will therefore interact with particles differently than 1064 and 532 nanometer wavelengths.

ISS SERVIR Environmental Research and Visualization System (ISERV)

by on 2 May 2015in Earth Science and Remote Sensing

Sensor

  • Celestron CPC-925 telescope with shorter fork arms from a CPC-800. 9.25″ telescope uses the HyperStar lens to operate at a fast f/2.3 focal ratio
  • Canon EOS 7D digital SLR is mounted on the HyperStar lens to capture images
  • Nadir Spatial Resolution: resolution of 10 feet per pixel, but gives a field of view 19 km x 11 km area
  • Spectral Bands: Visible to near IR
  • Pointing: WORF facility in the Destiny Laboratory Window