Avigdor Blasberger’s research while affiliated with Israel Aerospace Industries Ltd. and other places

Utilization of Pan Chromatic and Multi Spectral Remote Sensing Imagery is wide spreading and becoming an established business for commercial suppliers of such imagery like ISI and others. Some emerging technologies are being used to generate Hyper-Spectral imagery (HSI) by aircraft as well as other platforms. The commercialization of such technology for Remote Sensing from space is still questionable and depends upon several parameters including maturity, cost, market reception and many others. HSI can be used in a variety of applications in agriculture, urban mapping, geology and others. One outstanding potential usage of HSI is for water quality monitoring, a subject studied in this paper. Water quality monitoring is becoming a major area of interest in HSI due to the increase in water demand around the globe. The ability to monitor water quality in real time having both spatial and temporal resolution is one of the advantages of Remote Sensing. This ability is not limited only for measurements of oceans and inland water, but can be applied for drinking and irrigation water reservoirs as well. HSI in the UV-VNIR has the ability to measure a wide range of constituents that define water quality. Among the constituents that can be measured are the pigment concentration of various algae, chlorophyll a and c, carotenoids and phycocyanin, thus enabling to define the algal phyla. Other parameters that can be measured are TSS (Total Suspended Solids), turbidity, BOD (Biological Oxygen Demand), hydrocarbons, oxygen demand. The study specifies the properties of such a space borne device that results from the spectral signatures and the absorption bands of the constituents in question. Other parameters considered are the repetition of measurements, the spatial aspects of the sensor and the SNR of the sensor in question.

Commercial satellite remote sensing is a rapidly growing market, some projections indicating revenues from the sale of data and GIS products totaling over $12B by 2003. Though commercial remote sensing may be promising, there have been some limiters to the growth of the market over the past few years, including the costs per image, the not-so-timely acquisition of data and delivery to the customer, and others. One current inhibitor to the growth of the market is the cost of commercial images. Most commercially provided data range from$1,500 to $4,000 per scene, depending on the resolution and size of the image, with more integrated GIS products costing as high as$10,000 for one image. A second inhibitor is the difficulty in translating spectral signatures into useful and accurate information without weeks of ground research. Another potential inhibitor is the timeliness in acquiring satellite images. At present, it takes anywhere from two days to well over four weeks before customers receive imagery from vendors. This time lapse can be a problem for users of imagery with rigid time constraints (e.g., agricultural or media interests). Due to these inhibitors, the success of a remote sensing system depends not just on the spectrum and resolution of the data, but also on other factors important to customers such as image cost, speedy access to data, service reliability, and other figures of merit relevant to a customers needs. ELOP has examined how these various figures of merit become beneficial to different applications as they vary in performance. Applications such as Agriculture, Forestry, Geology, Coastal & Water and many other, were compared with variations in spatial resolution, spectral resolution, spectral range, revisit rate, data delivery speed, and others. A condensed version for varying figures of merit evaluated with some expected applications will be presented and the various parameters analyzed for variable revisit rate with a conclusive approach for the optimal solution.

A new era in commercial remote sensing from satellites is beginning, with the emergence of high-resolution cameras that approach the capabilities of aerial photography. The first satellite of the EROS constellation will be launched in a few months and will provide panchromatic images of the Earth at a resolution of 1.8 m. Subsequent units will follow with one meter class panchromatic systems and 3.2 m multi-spectral channels. The constellation will allow high revisit rates and large data collection capacity over most of the Earth. The paper will describe the payloads planned for the series with emphasis on the technological features of the cameras.

The 'DAVID' satellite is designed to provide earth images with high spatial and spectral resolution and good radiometric sensitivity, despite its small size and low cost. It will have more spectral bands in the VNIR than sensors on most existing or planned multi-spectral satellites and higher ground resolution than planned hyper-spectral space sensors like LEWIS and MODIS. The development is a joint German-Israeli co-operative project. Existing space-rated sub-systems will be used or adapted for this system, combined with new satellite and detector technologies, to achieve the low cost and high performance goals. The two principal companies involved, OHB in Germany and El-Op in Israel are both experienced in the design and construction of space systems, some of which have already been successfully launched. In addition, another German company, GAF, is actively involved in the parameter definition and image product distribution aspects of the system. A feasibility study has now been completed. This paper will describe the updated system concept.

The TAUVEX space astronomy experiment will image wide sky areas in the 190–280 nm spectral region. The experiment is part of the SODART telescope complex on the Spectrum X-Gamma (SRG) spacecraft, and functions as a separate scientific instrument and service system for the spacecraft. TAUVEX consists of three bore-sighted telescopes with 20 cm diameter Ritchey-Chretien optics. Each telescope has a four-position filter wheel and can select one of six UV bands in the spectral region of operation. The photon-counting, imaging detectors cover a field of view of 0.9 degrees, with 80% of the energy from a point source within 10 arcsec, sampled at 3 arcsec intervals. The sensitivity allows the detection of 10–11 mag stars in 2 sec, and 20 mag stars in a typical SRG pointing of 5 hr.TAUVEX provides off-line aspect solutions for the SODART focal plane instruments and on-line fine pointing information to the SRG attitude and control system. The experiment is being constructed by El-Op Electro-Optical Industries Ltd, and is financially supported by the Government of Israel, through the Israel Space Agency, and the Ministry of Science and Arts. By mid-1994, four models of TAUVEX had been produced and supplied to the SRG integrators: size and mass models in 1992, a thermal model in early 1993, and an engineering model in spring 1994. A qualification model is being tested at El-Op and the flight model will be ready, after testing, burn-in and calibration, in the first quarter of 1997.

The TAUVEX space astronomy experiment to image wide sky areas in the 140 - 280 nm spectral region is part of the SODART telescope complex on SRG, and functions as a separate scientific instrument and as a service system for the spacecraft. The experiment consists of three bore-sighted telescopes with 20 cm diameter Ritchey-Chretien optics. Each telescope is equipped with a four-position filter wheel and can select one of six UV bands in the spectral region of operation. The photon-counting, imaging detectors cover a field of view of 0 degree(s).9, with 80% of the energy from a point source within about 10 arcsec. The image is sampled at 3 arcsec intervals. The sensitivity is such that stars of 10 - 11 mag in the UV are detected in 2 sec, and in a typical SRG pointing of 5 hours stars as faint as 20 mag are detectable. TAUVEX provides off-line aspect solutions for the SODART focal plane instruments and on-line fine pointing information to the SRG attitude and control system. The experiment is constructed by El-Op, Electro-Optical Industries Ltd., and is financially supported by the Government of Israel, through the Israel Space Agency and the Ministry of Science and Arts. By mid-1994 four models of TAUVEX had been produced and supplied to the SRG integrators: size and mass models in 1992, a thermal model in early 1993 and an engineering model in spring 1994. A qualification model is being tested intensively at El-Op these days and the flight model will be ready, after testing, burn-in and calibration, by the end of 1994. TAUVEX is a light-weight, low-power, versatile UV imaging experiment with significant redundancy, which is not limited to operations on-board SRG. The system may operate on other platforms, including small satellites, if such an opportunity occurs.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The TAUVEX space astronomy experiment to image wide sky areas in the 140 - 280 nm spectral region is part of the SODART telescope complex on SRG, and functions as a separate scientific instrument and as a service system for the spacecraft. The experiment consists of three bore-sighted telescopes with 20 cm diameter Ritchey-Chretien optics. Each telescope is equipped with a four-position filter wheel and can select one of six UV bands in the spectral region of operation. The photon-counting, imaging detectors cover a field of view of 0 degree(s).9, with 80% of the energy from a point source within about 10 arcsec. The image is sampled at 3 arcsec intervals. The sensitivity is such that stars of 10 - 11 mag in the UV are detected in 2 sec, and in a typical SRG pointing of 5 hours stars as faint as 20 mag are detectable. TAUVEX provides off-line aspect solutions for the SODART focal plane instruments and on-line fine pointing information to the SRG attitude and control system. The experiment is constructed by El-Op, Electro-Optical Industries Ltd., and is financially supported by the Government of Israel, through the Israel Space Agency and the Ministry of Science and Arts. By mid-1994 four models of TAUVEX had been produced and supplied to the SRG integrators: size and mass models in 1992, a thermal model in early 1993 and an engineering model in spring 1994. A qualification model is being tested intensively at El-Op these days and the flight model will be ready, after testing, burn-in and calibration, by the end of 1994. TAUVEX is a light-weight, low-power, versatile UV imaging experiment with significant redundancy, which is not limited to operations on-board SRG. The system may operate on other platforms, including small satellites, if such an opportunity occurs.