Recent Developments in the Hyperspectral Environment and Resource Observer (HERO) Mission A. Hollinger, M. Bergeron, M. Maskiewicz, S.E. Qian, H.Othman Canadian Space Agency 6767 Rte de l'aeroport, St-Hubert, QC, J3Y 8Y9, Canada
[email protected]
K. Staenz, R.A. Neville
D.G. Goodenough
Canada Centre for Remote Sensing Natural Resources Canada 588 Booth Street, Ottawa, ON, K1A 0Y7, Canada
Pacific Forestry Centre Natural Resources Canada 506 Burnside Road W., Victoria, BC, V8Z 1M5, Canada
Abstract—In 1997, the Canadian Space Agency (CSA) and Canadian industry began developing enabling technologies for hyperspectral satellites. Since then, the CSA has conducted mission and payload concept studies in preparation for launch of the first Canadian hyperspectral earth observation satellite. This Canadian hyperspectral remote sensing project is now named the Hyperspectral Environment and Resource Observer (HERO) Mission. In 2005, the Preliminary System Requirement Review (PSRR) and the Phase A (Preliminary Mission Definition) were concluded. Recent developments regarding the payload include an extensive comparison of potential optical designs. The payload uses separate grating spectrometers for the visible near-infrared and short-wave infrared portions of the spectrum. The instrument covers a swath of >30 km, has a ground sampling distance of 30m, a spectral range of 400-2500 nm, and a spectral sampling interval of 10 nm. Smile and keystone are minimized. Recent developments regarding the mission include requirements simplification, data compression studies, and hyperspectral data simulation capability. In addition, a Prototype Data Processing Chain (PDPC) has been defined for 3 key hyperspectral applications. These are: geological mapping in the arctic environment, dominant species identification for forestry, and leaf area index for estimating foliage cover as well as forecasting crop growth and yield in agriculture. Keywords-hyperspectral; applications; HERO mission & payload; data compression; instrument performance analyses; international collaboration
I. INTRODUCTION In 1997, the Canadian Space Agency (CSA) and Canadian industry began developing enabling technologies for a possible hyperspectral mission. In 2001, the CSA began exploring various engineering and operational approaches to a spaceborne hyperspectral mission [1]. Since then, the CSA has conducted mission concept studies in preparation for launch of the first Canadian hyperspectral earth observation satellite [2]. This Canadian hyperspectral satellite mission is now named Hyperspectral Environment and Resource Observer (HERO). This culminated, in 2005, in the Preliminary System
Requirement Review (PSRR) and the completion of Phase A (Preliminary Mission Definition). The mission objective is to provide information-rich optical imagery that enhances decision-making and stewardship of sensitive ecosystems and natural resources. Hence, by a combination of selective imaging, mapping and regular monitoring, for example, HERO will improve efficiency and productivity, contribute to sustainable development in Canada and globally, strategically extend the Canadian investment in EO, provide accurate forest inventory and health information, map the geology of the North, and assess various environmental impacts. The mission builds on earlier Government of Canada research (e.g., [3]) and on Canadian industry’s experience and expertise in developing satellite instruments, airborne hyperspectral imagers and remote sensing applications. The mission will make new capabilities available for a wide variety of users that will provide economic, social and environmental benefits to Canada and the world. II.
MISSION CHARACTERISTICS
The PSRR provided a likely scenario for the detailed HERO sensor characteristics, as summarized in Table I. HERO will be an operational hyperspectral mission capable of covering an area of more than 600,000 km2 daily (with overlap). Hyperspectral data is information rich in that it samples, for each pixel in the image, the target radiance in hundred of bands. The end result is an image consisting of radiance spectra which can be transformed into reflectance spectra by correction of the influence of the atmosphere. These spectra provide information which allow to identify many target materials. HERO is a satellite with flexible tasking while large-area mapping will be performed as a background mission. An order desk tracks and manages orders. The planning unit then maximizes the resource utilization. Command and control messages are up linked to the satellite for data acquisition. Data are then downloaded and archived. A processing facility allows for the electronic delivery of data for the key mission
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applications. Value-added resellers may perform further data processing at this point. TABLE I.
PROPOSED CHARACTERISTICS FOR THE HERO MISSION.
Parameter Altitude Off-nadir viewing across track Swath width Track length Ground sampling distance (GSD) Geolocation with GCP Geolocation without GCP Average daily coverage Keystone Modulation Transfer Func. (MTF) Number of bands Spectral coverage Spectral sampling interval (SSI) Spectral resolution (FWHM) Smile Signal-to-noise ratio (SNR) Radiometric accuracy Quantization Equator crossing time Frequency of re-look Latency of satellite tasking Latency of delivery Mission life Technological demonstration
Value ~700 km ±7° (Nominal), ±20° (Occasional) ≥30 km Up to 200 km 30 m ~30 m ~1 km >600,000 km2 200 400 – 2500 nm 10 nm ~10 nm (full width at half maximum)
