hyperspectral imager for the coastal ocean (hico): a space-borne
TRANSCRIPT
This poster describes the Hyperspectral Imager for Coastal Oceans (HICO) sensor and the operational processing required to convert raw HICO data to bio-optical ocean products. The HICO sensor history and specifications are shown. Both HICO multispectral and hyperspectral processing streams are used to generate inherent optical property estimates. Various true color images of selected HICO data sets are shown. A process to refine the calibration by using insitu Remote Sensing Reflectance (Rrs) measurements is discussed. Data products generated from HICO data sets of Bahrain and Hong Kong are presented.
Number of Spectral Bands 128
Spectral Wavelength Range 350 - 1080 nmeter
Spectral Wavelength Bandwidth 5.7 nmeter
Ground Sample Distance (at Nadir) 100 meters
Signal to Noise Ratio (water-penetrating wavelengths) > 200 to 1
Polarization Sensitivity < 5%
Scene Size (varies according to ISS height) 50 x 200 km
Cross-track pointing 45 to -30 degress
Maximum scenes per orbit 1
Maximum number of orbits (scenes) per day 15
The Automated Processing System (APS) was developed at NRL as a collection of UNIX programs and shell scripts. APS automatically processes satellite imagery and generates map-projected image data bases of ocean color products from satellite data. Several temporal composites of ocean color data products and quick-look “browse” images are automatically generated in JPEG format. APS was originally developed for multispectral imagery from polar-orbiting satellites such as the Advanced Very High Resolution Radiometer (AVHRR), the Moderate Resolution Imaging Spectroradiometer (MODIS), the Medium Resolution Imaging Spectometer (MERIS), the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), the Coastal Zone Color Scanner (CZCS), and the Ocean Colour Monitor (OCM) sensors. APS is being modified to handle the hyperspectral data stream of he HICO sensor.
The Hyperspectral Imager for Coastal Oceans (HICO) was established as an Innovative Naval Prototype (INP) from the Office of Naval Research (ONR). The HICO sensor is the first spaceborne hyperspectral imaging spectrometer designed to sample coastal oceans. The sensor was installed on the International Space Station (ISS) (Figure 1) to provide hyperspectral imagery for the study of the coastal ocean and adjacent lands. The ISS platform and orbit will allow sampling of selected coastal regions at different angles and times of the day and will provide unique viewing geometry different from existing sun-synchronous, polar orbiting sensors.
The Naval Research Laboratory (NRL) built the HICO sensor and manages its operations, including target selection and scene acquisition. NRL receives the raw HICO data, calibrates the data and generates a variety of ocean color data products through a series of automated processing systems. NRL and ONR will evaluate HICO as a prototype for installing hyperspectral sensors on future polar-orbiting platforms.
The history of HICO is:• January 2007: HICO was selected to fly on the ISS• November, 2007: construction began following the Critical Design Review• August, 2008: sensor integration was completed • April, 2009: shipped to Japan Aerospace Exploration Agency (JAXA) for launch• September 10, 2009: HICO launched on JAXA H-II Transfer Vehicle (HTV)• September 24, 2009: HICO installed on ISS Japanese Module Exposed Facility
David Lewis 1, 228-688-5280, [email protected]; Bob Arnone1, 228-688-5587, [email protected]; Brandon Casey1, 228,688,4770, [email protected]; Weilin Hou1, 228-688-5257, [email protected]; Richard Gould1, 228-688-5268, [email protected]; Sherwin Ladner1, 228-688-5754, [email protected]; Adam Lawson1, 228-688-4473, [email protected] ; Paul Martinolich1, 727-712-0032; [email protected]; Marcos Montes2, 202-767-7308, [email protected]; Karen Patterson2, 202-767-0043, [email protected]; Theresa Scardino1, 228-688-6049, [email protected]; Ronnie Vaughan1, 228-688-4873, [email protected]
1) Naval Research Laboratory, Building 1009, Code 7330, Stennis Space Center, MS 39529; 2) Naval Research Laboratory, Code 7230, 4555 Overlook Ave. SW, Washington, DC 20375
Hyperspectral Imager for the Coastal Ocean (HICO): A Space-Borne Earth Observation Sensor for Ocean Color InvestigationsAbstract Reference Number: 749433, Paper Number: IT35A-07
Figure 1. HICO sensor and its location on the Japanese Module Expose Facility
I. Abstract
Level 0 Level 01a –Navigation
Level 1b-Calibration
Level 2a: Sunglint
Multispectral
Level 2c: Standard APS Multispectral Algorithms Products
QAA, ProductsAt, adg,
Bb, b. CHL (12)
NASA:standards
OC3, OC4, etc (9)
Navy ProductsDiver Visibility
Laser performance K532,
etc (6)
Level 3: Remapping Data and Creating Browse Images
Level 2b –TAFKAA
Atmospheric Correction
Level 2f: Cloud and Shadow
Atm Correction
Level 2c- :Hyperspectral
L2gen-Atm Correction
Atmospheric Correction Methods
Level 2d:Hyperspectral
Algorithm Derived Product
Hyperspectral QAA
At, adg,Bb, b. CHL
(12)
CWST - LUT Bathy,
Water Optics Chl, CDOM
Coastal Ocean Products Methods
HOPE Optimization
(bathy, optics, chl,CDOM ,At, bb, etc
Vicarious Calibration
Level 1b :Calibration
Hyperspectral
Level 1c – Modeled Sensor bands
MODIS MERISOCM
SeaWIFS
Chesapeake Bay 10/20/09 Data Set
VII. SummaryNRL developed and configured the Hyperspectral Imager for Coastal Oceans (HICO) sensor, which is now installed on the International Space Station. Data acquisition, data calibration and data product generation has begun. Calibration can be refined by using insitu data sets coincident with HICO data acquisition. As the calibration is refined, a wide variety of bio-optical ocean products will be generated to support both Navy and scientific missions in open-ocean and coastal waters. Furthermore, the 100 meter spatial resolution of HICO will enable investigations of riverine and estuarine environments. With the wealth of contiguous spectral wavelength information, HICO will facilitate development of new hyperspectral algorithms and ocean products, and will advance our understanding of phenomena that are better identified in more narrow wavelengths than current multispectral satellite sensors provide.
(For more information on HICO’s comparison to MODIS and MERIS see Poster B035A-02)
IV. Data Processing
HICO data will be processed by APS in two different data streams (Figure 2)
1. Multispectral stream• hyperspectral HICO bands were convolved using sensor-specific spectral response
functions to simulate multispectral data from other sensors• advantage: resulting multispectral data can then be processed by standard
multispectral APS functions2. Hyperspectral stream
• APS will be modified to incorporate atmospheric correction for hyperspectral dataincluding an extension of standard SeaWIFS/MODIS multispectral algorithms (N2GEN) with Near InfraRed (NIR) iteration, TAFKAA, and Cloud Shadow correction
• Ocean color products will be generated from atmospherically correctedhyperspectral data
Figure 3: Top of Atmosphere (TOA) Radiance True Color Images of Selected HICO Scenes
Figure 4aTOA Radiance True Color
Figure 4bRrs at 547 nm band
Refinement for data calibration with in situ data was performed in the following manner:• HICO radiance data were processed to Remote Sensing Reflectance (RRS) with APS• in situ radiometer data (RRS) were collected in Chesapeake Bay coincident to HICO scene• in situ Rrs and HICO Rrs data were compared to update the calibration gain factors • data set was reprocessed through APS with updated gain factors
Results (land area is depicted by an orange or black land mask in the figures below)• top of the atmosphere radiance measurements shown in Figure 4a• image of reprocessed Rrs measurements is shown in Figure 4b• resulting radiometer and HICO Rrs comparison shown in Figure 4c• ocean color products generated through APS are shown in Figures 5a, 5b and 5c
Insitu Station #2
Pusan, South Korea Hong Kong, China Key Largo, Florida Han River, South Korea
Bahrain Yangtze River, China Bahamas Turkish Straights
II. Background
Table1. HICO sensor parameters
III. Objectives
The objectives of this poster are to:
1. introduce the HICO sensor2. discuss the data processing system3. show true color imagery of selected HICO data scenes4. explore calibration using in situ data5. present ocean color data products generated from the HICO sensor
V. Data Collection
VI. Data Calibration
Insitu Station #3
Insitu Station #4
0.000
0.002
0.004
0.006
0.008
0.010
0.012
412 443 488 531 547 667 678 748 869
HICO and Insitu Radiometer Rrs Data at Station 3
HICO_at_Station_3
ASD_at_Station_3
0.000
0.002
0.004
0.006
0.008
0.010
0.012
412 443 488 531 547 667 678 748 869
HICO and Insitu Radiometer Rrs Data at Station 4
HICO_at_Station_4
ASD_at_Station_4
0.000
0.002
0.004
0.006
0.008
0.010
0.012
412 443 488 531 547 667 678 748 869
HICO and Insitu Radiometer Rrs Data at Station 2
HICO_at_Station_2
ASD_at_Station_2
Figure 4cHICO and Radiometer Rrs
Figure 5aBahrain 11/18/09Backscatter (bb)
at 547 nmeterUnits = 1/m
Figure 5bBahrain 11/18/09
Diffuse Attenuationat 547 nmeterUnits = 1/m
After acquisition, data is calibrated and geolocation information is added to create Level 1B data. The multispectral and hyperspectral data streams are automatically processed from the Level 1B file by APS. Further refinement of both the calibration and APS data product generation processes is in progress. Examples of true color images created from the top of the atmosphere radiances for selected HICO data sets are shown in Figure 3.
Figure 2: HICO’s APS Processing Flow
Wavelength (nm)
Wavelength (nm)
Wavelength (nm)Open Ocean
Annapolis, Maryland
Open Ocean
N N
Figure 5c Hong Kong 10/02/09
Backscatter (bb)at 547 nmeterUnits = 1/m
Figure 5dHong Kong 10/02/09Diffuse Attenuation
at 547 nmeterUnits = 1/m