Draft vesion 3.0 dated 27 September 2015 Science plan document ISRO - NASA AVIRIS – NG Airborne Flights over India Science Plan Document for Hyperspectral Remote Sensing 1 Draft vesion 3.0 dated 27 September 2015 Science plan document CONTENTS Page no. 1.0 INTRODUCTION AND BRIEF HISTORY 3 2.0 HYPERSPECTRAL APLICATIONS 4 2.1 GLOBAL SCENARIO 4 2.2 INDIAN SCENARIO AND CURRENT STATUS 5 3.0 NEED FOR HYPERSPECTRAL 8 AIRBORNE/SPACE BORNE MISSION 4.0 MAJOR SCIENCE GOALS OF THE 13 HYPERSPECTRAL MISSION (Themes, proposed sites, methodology, expected outcome) 5.0 CALIBRATION OF AIRCRAFT AND SATELLITE 59 SENSORS REFERENCES 61 2 Draft vesion 3.0 dated 27 September 2015 Science plan document 1.0 INTRODUCTION AND BRIEF HISTORY Imaging spectroscopy is of growing interest as a new approach to Earth Remote Sensing. With the advent of hyperspectral remote sensors, both airborne and space-borne, along with the high storage capacity of the fast computing systems and advanced software to store and process the hyperspectral data, it is now possible to detect and quantify various earth resource materials (Goetz, 2009). The original definition for imaging spectrometry proposed by the author and others (Goetz et al., 1985) was given as “the acquisition of images in hundreds of contiguous, registered, spectral bands such that for each pixel a radiance spectrum can be derived.”Hyperspectral sensors or imaging spectrometers collect unique data that are both a set of spatially contiguous spectra and spectrally contiguous images (Goetz et al. 1985). One of the earliest applications of hyperspectral remote sensing identified was geological mapping and its commercial role in mineral exploration. The development of terrestrial imaging spectroscopy, as documented by Staenz, 2009, started in the late seventies by NASA’s Jet Propulsion Laboratory (JPL) and a government of Canada/private partnership (Department of Fisheries and Ocean/Moniteq) leading to the Airborne Imaging Spectrometer (AIS; Vane and Goetz, 1988) in the U.S.A. and the Fluorescence Line Imager (FLI; Gower et al., 1987) in Canada with first data acquisitions in 1983 and 1984, respectively. These activities led in 1987 to the first visible and near-infrared (VNIR) and short-wave infrared (SWIR) sensor, JPL’s Airborne Visible/Infrared Imaging Spectrometer (AVIRIS; Green et al., 1998; Vane et al., 1993) and in 1988 to the first commercial instrument, Itres’ Compact Airborne Spectrographic Imager (casi; Anger et al., 1990). Many more airborne systems have been developed since that time (e.g., Buckingham, 2008; Birk and McCord, 1994). The first successfully launched civilian hyperspectral satellite sensor, NASA’s Hyperion on EO-1, has been in orbit since 2000 (Pearlman, 2003). A year later, the Compact High Resolution Imaging Spectrometer (CHRIS) on board ESA’s Project for On-Board Autonomy (PROBA) platform was launched (Barnsley et al., 2004). Both systems are still operating today, providing imagery in the VNIR (CHRIS) and VNIR/SWIR (Hyperion). With the current launches of ISRO’s VNIR HyperSpectral Imager (HySI) on board the Indian Microsatellite 1 (IMS-1) and the Chinese VNIR HJ-1A satellite sensor in 2008, new opportunities will arise for the use of hyperspectral data in various application areas due to the larger ground sampling distance (GSD) (≥100 m) combined with a larger swath width (≥ 50 km) of these sensors (Goetz, 2009; Staenz, 2009). Data handling and correction of sensor artefacts dominated software development in the early phases of imaging spectroscopy, followed by an intense period of algorithm development (AVIRIS, 2007). Innovative procedures, such as atmospheric correction and spectral linear unmixing, were developed (Staenz and Williams, 1997; Neville et al. 2008). These procedures together with the capability to handle hyperspectral data were incorporated into several hyperspectral image analysis systems by government and academic institutions and, ultimately, resulted in the release of the first commercial system, ENVI, in 1994 (Boardman 3 Draft vesion 3.0 dated 27 September 2015 Science plan document et al., 2006). With the availability of ENVI, the development of applications increased significantly, making imaging spectroscopy an important tool in areas such as climate change, resource management, and environmental monitoring and assessment as, for example, shown in the AVIRIS Workshop proceedings (AVIRIS, 2007). Additional hyperspectral image analysis systems have emerged, such as the hyperspectral packages in ERDAS Imagine and in PCI Geomatica (Goetz, 2009; Staenz, 2009). 2.0 HYPERSPECTRAL APPLICATIONS 2.1 GLOBAL SCENARIO The term “hyperspectral imaging” was first coined by Goetz et al. (1985) in a paper discussing the early results of the technique of imaging spectrometry. Hyperspectral imaging has enabled applications in a wide variety of Earth studies (Goetz, 2009). The prime motivation for the development of imaging spectrometry was mineralogical mapping of surface soils and outcrops (Abrams et al., 1977; Goetz et al., 1985). The reflectance spectra of minerals are rich in electronic as well as overtone and combination vibrational features that characterize surfaces that are relatively vegetation-free (Clark et al., 1990). Only approximately 30% of the land surface is relatively devoid of vegetation and the remaining 70% is covered by vegetation to the extent that the substrate is rendered inaccessible to remote sensing identification (Siegal and Goetz, 1977). However, the vegetation cover, its type, health, vigor and expression of environmental conditions including the substrate are the subject of many ongoing studies (Goetz, 2009). Wessman et al. (1988) identified tree species for the first time based on nitrogen and lignin content in the foliage. They used statistical regression techniques also known to spectroscopists as chemometrics (Mark, 1989) and built a prediction model based on known occurrences of broadleaf and evergreen species on Blackhawk Island, WI. As follow-on to the HIRIS project, NASA funded the Accelerated Canopy Chemistry Program in which chemometrics techniques were used successfully on AVIRIS data acquired over the Harvard Forest, MA (Aber & Martin, 1995; Martin and Aber, 1997) (Source: Goetz, 2009). Other diverse studies of species and canopy health, water content as well as relative abundances of photosynthetic (PV) and non-photosynthetic (NPV) vegetation in a pixel can be found in papers by Gamon et al. (1992, 1993), Ustin et al. (1992, 1998), Roberts et al. (1993, 1998), and Asner and Lobell (2000) (Source: Goetz, 2009). Studies of the coastal zone are better served by hyperspectral imaging, which makes it possible to unmix the bottom and several in-column constituents (Carder et al., 1993; Lee et al., 1994). Hyperspectral imaging is equally applicable to the solid water phase which makes it possible to study the properties of ice and snow, in particular grain size (Nolin & Dozier, 1993; Painter et al., 1998). Environmental studies using hyperspectral imaging are yielding results that would be impossible to obtain or would be prohibitive in cost or time spent with standard techniques. One example that has been documented to have saved millions of dollars 4 Draft vesion 3.0 dated 27 September 2015 Science plan document is in the cleanup of the Leadville, CO Superfund Site in which AVIRIS images combined with field spectral measurements identified the waste piles with the greatest potential for leaching heavy metals into streams and groundwater (Swayze et al., 2000). Asbestiform minerals have also been identified in situ from AVIRIS data (Swayze et al., 2005). Maps of expansive soils, important in construction engineering, can also be identified in AVIRIS images (Chabrillat et al., 2002) (Source: Goetz, 2009). 2.2 INDIAN SCENARIO AND CURRENT STATUS Indian researchers are actively engaged in making use of the potential of hyperspectral data since late 1990’s and early 2000’s in various fields of applications such as agriculture, precision firming, pest and disease, forestry, coastal applications and geological and mineral exploration and spectral library related activities. Land applications include vegetation studies (species identification, plant stress, productivity, leaf water content, and canopy chemistry), soil science (type mapping and fertility status), geology (mineral identification and mapping) and hydrology (snow grain size, liquid/solid water differentiation). Lake, river and ocean applications include biochemical studies (photoplankton mapping, activity), water quality (particulate and sediment mapping) and bathymetry. Atmospheric applications include parameter measurement (water vapor, ozone, and aerosols) and cloud characteristics (optical thickness, cirrus detection, particle size). All these work were carried out in collaboration with various state and national agencies relevant in respective fields and the study sites also were spread over various parts over India. Few studies also been carried out for wetland ecosystem and the results showed that different wetland plats have similar spectra curves while they still possible to be distinguished in some visible and NIR in hyperspectral data. Many applications with hyperspectral data were carried out for mineral exploration, and snow studies in the Himalayan region. These studies showed the capability of hyperspectral data for identifying and quantifying minerals and rocks as well as mapping the indicators for mineral exploration; and for studying the effect of contamination and grain size variability on snow. These studies also derived the optimum hyperspectral bands for these studies. Earth and Planetary Sciences Applications Geological mapping and mineral exploration are are better manifested in spectral signatures and spatial distributions identifiable through remote sensing techniques. This helps in delineating exploration targets for metals and industrial minerals (Kruse 1988). Studies on laboratory spectroscopy (Hunt and Salisbury 1970, Clark et al. 1990) and data using remote imaging spectrometers (Kruse 1988, Kruse et al. 1990, Staenz and Williams 1997, Kruse et al. 2003, Neville et al. 2003) have well established its efficiency in mineral identification, quantification, mapping and exploration. Detailed field based spectral measurements are being carried out at various places in India in order to characterize the spectral features of exposed mineral guides such as the Gossans mostly associated with poly-metallic sulphide deposits, hydrothermal alteration zones 5 Draft vesion 3.0 dated 27 September 2015 Science plan document associated with porphyry copper deposits, iron ores, bauxites and laterites spread over vast expanses of Deccan Traps, mapping of Uraniferous calcretes in the spectral range of 350- 2500 nm (Bharti et al., 2012; Bharti and Ramakrishnan, 2014; Bhattacharya et al., 2012; Das and Bhattacharya, 2012; Guha et al., 2013; Kusuma et al., 2012; Ramakrishnan et al., 2013; Sanjeevi, 2008; Sanjeevi et al., 2012??). A spectral cataloguing of the rocks and minerals associated with the mineralogical provinces and Precambrian terrain of eastern and northern Gujarat has also been prepared (Das and Bhattacharya, 2012). Work is also being carried out at SAC on the spectral characterization of Martian analogues from the Deccan Volcanic Province of Kachchh, Gujarat and Rakhabdev Ultramafic Suites of Rajasthan (Bhattacharya et al., 2012; Jain et al., 2011, 2012). Jarosite, an iron-bearing hydrous sulphate and a key Martian mineral having astrobiological significance has been reported for the first time from the laterite profile developed over the Deccan basalts at Kachchh near Matanumadh village, Gujarat (Bhattacharya et al., 2012; Jain et al., 2011) and a systematic spectroscopic and geochemical studies are being carried out at the laterite section of Matanumadh. Moreover, Bhattacharya et al. (2013, 2014) reported the presence of a Al-rich phyllosilicate over Fe-Mg- smectite stratigraphy developed in the saprolite-laterite profile at Matanumadh, similar to those observed at Mawrth Vallis and Meridiani Planum regions on Mars indicating changes in the paleoclimatic and paleodrainage conditions in the Kachchh region owing to the tectonic disturbances that the area had underwent in the past and is currently undergoing. India’s airborne imaging spectrometers, namely, Airborne IMaging Spectrometer – 2 (AIMS- 2) and Airbone HyperSpectral Imager (A-HySI) were flown over the Shivrajpur-Khandia region of Gujarat in order to map the open cast manganese mine at Shivrajpur and the nearby old workings. The spectra were compared with the field based spectra of manganese ores. In Space-based Imaging Spectroscopy Bhattacharya et al. (2012) has detected and mapped the presence of altered/clay minerals by utilizing the 2.0-2.4 µm spectral range of EO-1 Hyperion over parts of Dongargarh, Chattisgarh in conjunction with in situ field-based spectral measurements. Furthermore, Imaging spectrometers are one of the most important tools used for the remote compositional assessment of any planetary surface. SAC-ISRO is actively involved in analyzing the data from Chandrayaan-1 hyperspectral instruments for compositional and mineralogical characterization of the lunar surface (Bhattacharya et al., 2011, 2012, 2013; Kaur et al., 2013; Lal et al., 2012). One of the major Indian contributions to Chandrayaan-1 mission and overall lunar science include the discovery of magmatic water on the Moon for the first time based on remote orbital measurements associated with non-mare silicic volcanic constructs (Bhattacharya et al., 2013). Apart from that, Indian researchers are also involved in the discovery of a new mineral “Spinel” on the lunar surface based on remote measurements (Bhattacharya et al., 2012, 2013, 2014; Chauhan et al., 2014, 2015; Lal et al., 2011, 2012; Kaur and Chauhan, 2014; Kaur et al., 2012, 2013a, 2013b; Srivastava et al., 2013). Apart from Moon, Jain and Chauhan (2015) and Jain et al. (2014) has detected and mapped the presence of phyllosilicates and carbonates from the Capri Chasma region within the Valles Marineris area of Mars highlighting the past liquid water activity on Mars. 6 Draft vesion 3.0 dated 27 September 2015 Science plan document Snow, Glacier and Cryospheric Research Field based spectroradiometer observations have been taken for varying properties of snow physical properties in the Beas basin along with collateral data. Snow reflects strongly in the visible region and decreases in the NIR and SWIR region. The effect of various atmospheric and meteorological conditions influences the snow properties and reflectance which has been studied using ground based instruments. Hyperion satellite data was used to retrieve the grain size in part of Himalayas. Singh et al. (2010, 2011) had studied the effects of soil and coal contamination and grain size on the snow reflectance. Continuous field-based spectral measurements have been conducted in the Himalayan cryosphere which are useful to develop new algorithms for retrieving various snow and glacier parameters (Negi et al., 2015). Agricultural Applications Agriculture forms important field for hyperspectral studies owing to diversity in the crop growing conditions and management practices. These complexities get compounded to variety of factors such as soil, water, management and crop varieties etc. In the field of crop science major works carried out are - Pulse crop discrimination, Crop stage discrimination and analysis of angular effect, Crop biophysical parameter retrieval, Tea crop discrimination studies and crop residue studies. These studies identified important narrow bands required for pulse crop discrimination, important view angle and hyperspectral indices for crop stage discrimination, identified hyperspectral indices for LAI and plant nitrogen estimation, Optimum bands for tea crop identification, optimum bands as well as important indices for crop residue studies. Crop disease discrimination in mustard crop was carried out by Bhattacharya and Chattopadhyay (2013) using EO-1 Hyperion data over Bharatpur region in Rajasthan For soil science, hyperspectral data were used for Soil fertility parameter retrieval and mapping, Soil variability mapping and fertility zonation, Estimation of Soil parameters like bulk density, EC, nitrogen, phosphorus etc. These studies concluded that several soil properties, namely, surface condition, particle size, organic matter, soil colour, moisture content, iron and iron oxide content and mineralogy can be mapped through imaging spectroscopy and that hyperspectral data can be effectively used for generating soil variability and fertility zonation. Crop stage discrimination using IMS-1 HySI has also been carried out. Works have carried out to develop Spectral signature bank and prototype spectral library of vegetation; develop Software for Reflectance Spectra Analysis and PROSAIL Model Inversion. Forestry Applications In the field of forestry major works carried out at SAC are - Forest species discrimination and biochemical parameter retrieval, Mangrove species identification and Discrimination of Mangrove ecosystem components and associated features. The results confirmed that there 7 Draft vesion 3.0 dated 27 September 2015 Science plan document are significant differences in pigment levels, and optical properties for leaves of tropical dry forests. Different variables of leaves of forest species like phenology, age etc can be discriminated based on their spectral reflectance properties. These studies also found out the best classifier for forest species discrimination. Discrimination of forest species and narrow band indices correlation with biochemical components were studied. The components of hyperspectral pre processing and classification algorithms were also evaluated for forest species. Wetland Ecosystem The deterioration of the ecological status of continental waters (dams, lakes, lagoons) has become an urgent and growing problem in the last years. In this regard, evaluation of hyperspectral data for wetland ecosystem was done for Chilika Lagoon, Orissa Biological Oceanographic Applications Exhaustive studies using under water radiometer has been done in coastal and open ocean waters of Arabia sea and Bay of Bengal for Phytoplankton function types and various species identification. Also, studies were conducted for water quality evaluation, IOPs and eutrophication studies of inland water bodies using underwater radiometer. Coastal water studies for geophysical parameter retrieval were extensively carried out in Arabian sea. 3.0 NEED FOR HYPERSPECTRAL AIRBORNE/SPACE BORNE MISSION Hyperspectral imager (HSI) can detect the individual absorption features, since all the materials are bound by chemical bonds, thus they can be identified by their spectral characteristics more accurately as compared to broad band multi-spectral imagers. Spaceborne hyperspectral data have three potential advantages over space borne multispectral sensors- they can provide an enhanced level of information for atmospheric correction to derive surface reflectance; they can provide access to detailed spectral indices; they can be used to integrate the hyperspectral data consistently to synthetic bands equivalent to any other broad band sensors or to bands of yet to be developed instruments. Hyperspectral remote sensing technologies have allowed the development of an increasing number of spectral bands and, consequently, an improved capability for gaining a greater understanding of the fundamental processes that govern changes in the biophysical/biochemical properties of vegetation. Hence in the past many activities involving hyperspectral data (from ground based, airborne and space borne) were successfully planned and carried out at the Space Applications Centre, Ahmedabad. Applications are being pursued in all areas of Earth science including land, water and atmospheric topics. In mineral exploration, presence of hydrothermal alteration zones associated with granite batholiths, oxidized gossans with goethite/limonite/hematite capping are often act as important indicators for possible existence of sub-surface ore bodies. Hyperspectral remote sensors or imaging spectrometers can efficiently characterize these indicators based on diagnostic absorption features of hydrothermal alteration minerals and gossan assemblages, 8 Draft vesion 3.0 dated 27 September 2015 Science plan document primarily arising due to the electronic charge transition of Fe2+/Fe3+ and/or overtones and combination tones of hydroxyl and/or water and/or carbonates/sulphates in the crystal lattice of hydrothermal and gossan mineral assemblages, which are otherwise impossible to detect and characterize using broad-band or multi-spectral instruments as the bands in multi-spectral sensors are widely separated in spectral space and width of the individual spectral channels are so broad that these type of instruments cannot detect the diagnostic absorption features of minerals and rocks. Precise analysis of Band Center, Band Strength, and Band shape and asymmetry factor, Integrated Band Depth (IBD) /Bband Area and Band Curvature can help in discriminating amongst the dominant gossan mineral species and also one can study the relative abundances of the species present and generate fraction map. Spatial resolution of the space-borne hyperspectral instruments are not good enough to study the mineral prognostic zones and and the exposure sizes and vegetation cover play major roles in determining the discrimination capability of the space-borne hyperspectral instruments as coarser resolution will have more spectral mixing of endmember species. Therefore, there is a need to have airborne hyperspectral campaigns over mineral prognostic zones, areas of geological importance and volcanoes in a targeted mode to have better spatial resolution, which, in turn, will help in detecting more and more pure endmember mineral species and rock types thereby producing a better mineralogical and lithological map. There is a need to have various mineral and rock indices to detect and map guides for mineral exploration, to study the lava chemistry and pyroclastic deposits associated with active and dormant volcanoes and also to spectrally characterize the sites of geological importance such as paleo-subduction zones, exposed layered intrusive complexes, suture zones and ophiolites etc. AVIRIS-NG AND JPL Airborne Imaging Spectrometer (AIS) of JPL, NASA is considered as the first ever airborne hyperspectral instrument that was flown successfully for the first time over Cuprite, Nevada in August, 1983. The mineral identification success, and in particular the discovery of buddingtonite, an ammonium feldspar, became part of a Public Broadcasting System (PBS) documentary while the gold pathfinder mineral question was still open, led to a greater interest within NASA to pursue further sensor development (Goetz, 2009). In 1984, JPL proposed an imaging spectrometer program that would encompass an advanced airborne sensor, the airborne visible/infrared imaging spectrometer (AVIRIS), and two orbiting sensors, the shuttle imaging spectrometer experiment (SISEX) and a free-flyer, the high resolution imaging spectrometer (HIRIS) (Goetz, 2009). AVIRIS development was begun in 1984 and the imager first flew aboard a NASA ER-2 aircraft at 20 km altitude in 1987. Since then it has gone through major upgrades as technology changed in detectors, electronics and computing. AVIRIS is arguably the finest, best calibrated, airborne imaging sensor ever flown, which is the result of the dedication of the instrument leaders and their teams at JPL, Gregg Vane (Vane et al.,1993) and Robert O. Green (Green et al.,1998) and the continuing support of Diane Wickland of NASA Headquarters (Goetz, 2009). 9 Draft vesion 3.0 dated 27 September 2015 Science plan document In the late 1980's, several commercial hyperspectral imagers entered the market. The first was DAIS from Geophysical Environmental Research of Millbrook, NY (Richter, 1996). In 1989 ITRES Corporation, Alberta, Canada introduced CASI, an imaging spectrometer covering the visible and near-infrared region to 900 nm utilizing a 2-d silicon CCD array (Dekker et al.,1992). In 1994, the Naval Research Lab sensor HYDICE was completed (Basedow & Zalewski, 1995). This sensor was designed around a prism dispersion concept and a single, hybrid HgCdTe 2-d array to cover the 400–2500 nm spectral region. Although HYDICE began as a dual-use program, it soon reverted to an all DOD program. Other commercial sensors in this wavelength region are available. The one most like AVIRIS is the Australian sensor HyMap from the HyVista Corporation, which markets a full-range (400–2500 nm) hyperspectral imaging service on a global basis. Airborne Prism Experiment (APEX) is another recent imaging spectrometer, collecting information in the spectral range of 380-2500 nm and is developed by a Swiss-Belgian consortium for the European remote sensing community on behalf of ESA. It is also intended as a support for calibration and validation and a simulator for future spaceborne hyperspectral imagers (APEX Science Center - RSL – University of Zurich. contact: michael [email protected]; APEX Operation Center – VITO contact: [email protected]). The advanced AVIRIS instrument, i.e., AVIRIS-NG uses most advanced state-of the-art detector array and grating for dispersion of light. Most importantly, the blazing and grooving technique employed in the grating of AVIRIS-NG could successfully maintain the spectral as well as spatial uniformity, thus completely removing the SMILE and KEYSTONE effects that used to the integral part of all the earlier hyperspectral instruments. An example AVIRIS imaging cube is shown in Figure 1. A set of research and applications examples are included in this document from investigation pursued with AVIRIS in North America. For every example related AVIRIS data sets may be download so that early data processing preparation for the airborne campaign with AVIRIS-NG may begin. AVIRIS-NG is a higher performance, more recent instrument and the instrument planned for the airborne campaign. 10