Assessing the Application of Cloud-Shadow Atmospheric Correction Algorithm on HICO

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

Several ocean color earth observation satellite sensors are presently collecting daily imagery, including the Hyperspectral Imager for the Coastal Ocean (HICO). HICO has been operating aboard the International Space Station since its installation on September 24, 2009. It provides high spatial resolution hyperspectral imagery optimized for the coastal ocean. Atmospheric correction, however, still remains a challenge for this sensor, particularly in optically complex coastal waters. In this paper, we assess the application of the cloud-shadow atmospheric correction approach on HICO data and validate the results with the in situ data. We also use multiple sets of cloud, shadow, and sunlit pixels to correct a single image multiple times and intercompare the results to assess variability in the retrieved reflectance spectra. Retrieved chlorophyll values from this intercomparison are similar and also agree well with the in situ chlorophyll measurements.

Related URLs:

Estimation of chlorophyll-a concentration in productive turbid waters using a Hyperspectral Imager for the Coastal Ocean—the Azov Sea case study

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

We present here the results of chlorophyll-a (chl-a) concentration estimation using the red and near infrared (NIR) spectral bands of a Hyperspectral Imager for the Coastal Ocean (HICO) in productive turbid waters of the Azov Sea, Russia. During the data collection campaign in the summer of 2010 in Taganrog Bay and the Azov Sea, water samples were collected and concentrations of chl-a were measured analytically. The NIR–red models were tuned to optimize the spectral band selections and chl-a concentrations were retrieved from HICO data. The NIR–red three-band model with HICO-retrieved reflectances at wavelengths 684, 700, and 720 nm explained more than 85% of chl-a concentration variation in the range from 19.67 to93.14 mg m − 3 and was able to estimate chl-a with root mean square error below10 mg m − 3 . The results indicate the high potential of HICO data to estimate chl-a concentration in turbid productive (Case II) waters in real-time, which will be of immense value to scientists, natural resource managers, and decision makers involved in managing the inland and coastal aquatic ecosystems.

Related URLs:
http://stacks.iop.org/1748-9326/6/i=2/a=024023

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