TY - JOUR ID - bastiaanssen2000 AU - Bastiaanssen, Wim G. M. AU - Molden, David J. AU - Makin, Ian W. TI - Remote sensing for irrigated agriculture: examples from research and possible applications UR - http://www.sciencedirect.com/science/article/pii/S0378377400000809 DO - 10.1016/s0378-3774(00)00080-9 T2 - Agricultural Water Management PY - 2000 SN - 0378-3774 VL - 46 IS - 2 SP - 137-155 AB - Researchers in various international programs have studied the potential use of remotely sensed data to obtain accurate information on land surface processes and conditions. These studies have demonstrated that quantitative assessment of the soil-vegetation-atmosphere-transfer processes can lead to a better understanding of the relationships between crop growth and water management. Information on land surface can now be obtained at a wide range of spatial (5–5000 m) and temporal resolutions (0.5–24 days). However, even though considerable progress has been made over the past 20 years in research applications, remotely sensed data remain underutilized by practicing water resource managers. This paper seeks to bridge the gap between researchers and practitioners, first, by illustrating where research tools and techniques have practical applications and, second, by identifying real problems that remote sensing could solve, albeit with additional research and development. As freshwater becomes an increasingly scarce resource, all opportunities to better manage water uses, particularly in irrigated agriculture, must be taken. An important challenge in the field of water resources is to utilize the timely, objective and accurate information provided by remote sensing. KW - Remote sensing KW - Irrigated farming KW - Land management KW - Water resources management KW - Crop yield KW - Water use efficiency KW - Water rights ER - TY - JOUR ID - chandrasekhar1996 AU - Chandrasekhar, M. G. AU - Jayaraman, V. AU - Rao, M. TI - Indian remote sensing satellites: Planned missions and future applications UR - ://WOS:A1996VJ68200043 DO - 10.1016/0094-5765(96)00022-7 T2 - Acta Astronautica PY - 1996 DA - Feb-Apr SN - 0094-5765 VL - 38 IS - 4-8 SP - 647-658 N1 - Times Cited: 1 46th International-Astronautical-Federation Congress Oct 02-06, 1995 Oslo, norway Int Astronaut Federat AB - To cater the enhanced user demands, Indian Space Research Organisation is stepping a giant leap forward towards development of the state-of-the-art second generation Indian Remote Sensing Satellites, IRS-1C/1D following the successful design, launch and in-orbit performance of the first generation satellites, IRS-1A/1B. Characterised by improved spatial resolution, extended spectral bands, stereo-viewing and more frequent revisit capability, IRS-1C/1D are expected for launch during the timeframe of 1995-96\8. The IRS-1C and 1D, which are identical, will have three major payloads. The Linear Imaging Spectral Scanner (LISS-III) in four spectral bands covering from 0.52 to 1.70 microns will have a spatial resolution of 23m along with a swath of 142 km in the visible and NIR spectral bands and a spatial resolution of 70m along with a swath of 148 km in the SWIR spectral band. The Panchromatic Camera (PAN) with a spectral band of 0.50 to 0.75 microns will have a spatial resolution of <10m along with a swath of 70 km and a payload steering capability up to +/- 26 degrees. The Wide Field Sensor (WiFS) in visible and near IR with two bands and a spatial resolution of 188m will provide a swath of 774 kms. These sensors will provide better information on water stress, pest infestation and vegetation indices to arrive at better agricultural management practices, besides providing enhanced capabilities for arriving solutions for micro-level resource development and generation of digital terrain models. Having marked by the successful launch of IRS-P2 in 1994 through the indigenous development flight of PSLV, India is now poised to launch IRS-P3 satellite with unique payloads in the timeframe of 1995-96. The IRS-P3 will carry three operational payloads viz., Wide Field Sensor (WiFS), Modular Opto-electronic Scanner(MOS) imaging spectrometer and an X-ray Astronomy payload. These payload mix of sensors will provide further capabilities for application studies related to vegetation dynamics, oceanography and X-ray astronomy. With the launch of these payloads, India will provide more effective and assured data services to the user community beyond the 90's. ER - TY - JOUR ID - choubey1999 AU - Choubey, V. K. AU - Choubey, R. TI - Spectral reflectance, growth and chlorophyll relationships for rice crop in a semi-arid region of India UR - ://WOS:000083824500001 DO - 10.1023/a:1008056400348 T2 - Water Resources Management PY - 1999 DA - Apr SN - 0920-4741 VL - 13 IS - 2 SP - 73-84 N1 - ISI Document Delivery No.: 258EE Times Cited: 2 Cited Reference Count: 23 Choubey, VK Choubey, R Kluwer academic publ Dordrecht AB - Relations among spectral reflectance, chlorophyll 'a', and growth of rice plants grown on irrigated light textured soil in a semi arid region are presented here. There was a linear relation between spectral reflectance and rice plant height (r = 0.97), for band 1 (0.45-0.52 mu m) reflectance values. On the other hand, in bands 2 (0.52-0.60 mu m) and 3 (0.63-0.69 mu m), reflectance values decreased until 70 days after planting (DAP) and then increased during the reproductive phase of the crop. The near infrared band 4 (0.76-0.90 mu m) showed a maximum reflectance at 59 DAP (panicle initiation stage) and a decline in reflectance thereafter through maturity. The peak value of IR/R ratio was 16.39 at 62 DAP during the early reproductive phase; thereafter, it declines gradually with the maturity of the crop. Chlorophyll 'a' concentration was high during early growth (vegetative and early reproductive stages) and decreased during the flowering and maturity stages. The rice plant canopy show a high chlorophyll 'a' concentration at 64 and 59 DAP for sites A and B, respectively. Chlorophyll 'a' concentration is higher in site A plant canopies than it is in site B during the entire crop cycle. A good inverse correlation (r = 0.91) has been found between chlorophyll 'a' and band 1, while the IR/R ratio and the normalised difference vegetation index (NDVI) showed a relationship (r = 0.78) with the chlorophyll 'a' concentration during the crop cycle. Band 2, 3 and 4 radiance values show a biphasic linear relationship with chlorophyll 'a' concentrations, negative for early growth and positive for flowering and maturity stages. Results indicate that the period between 66 to 70 DAP is most suitable for the assessment of rice crop yield, based on chlorophyll 'a' concentration. KW - chlorophyll KW - growth KW - rice crop KW - spectral reflectance KW - red edge KW - leaf biochemistry KW - vegetation KW - prospect KW - model ER - TY - GEN ID - karnieli2001 AU - Karnieli, A. AU - Kaufman, Y. J. AU - Remer, L. AU - Wald, A. TI - AFRI - aerosol free vegetation index UR - http://www.ingentaconnect.com/content/els/00344257/2001/00000077/00000001/art00190 http://dx.doi.org/10.1016/S0034-4257(01)00190-0 DO - 10.1016/s0034-4257(01)00190-0 T2 - Remote Sensing of Environment PY - 2001 VL - 77 IS - 1 SP - 10-21 AB -

Aircraft measurements using a field spectrometer over variety of ground surfaces in Israel reveals that under clear sky conditions, the shortwave infrared (SWIR) spectral bands around 1.6 and 2.1 mum are highly correlated with the visible - blue, green, and red - spectral bands. Empirical linear relationships, such as rho0.469=0.25rho2.1; rho0.555=0.33rho2.1; rho0.645=0.5rho2.1; and rho0.645=0.66rho1.6, were found to be statistically significant and consistent with previous findings. Based on the above relationships, a modified vegetation index (VI) is proposed and named Aerosol Free Vegetation Index (AFRI). Two versions of this VI are formulated as: AFRI1.6=(rhoNIR-0.66rho1.6)/(rhoNIR+0.66rho1.6) and AFRI2.1=(rhoNIR-0.5rho2.1)/(rhoNIR+0.5rho2.1). It is shown that under clear sky conditions, the AFRIs (and especially AFRI2.1) closely resemble the Normalized Difference Vegetation Index (NDVI) and their values are almost identical. The advantage of the derived AFRIs, based on the ability of the SWIR bands, is to penetrate the atmospheric column even when aerosols such as smoke or sulfates exist. Consequently, these indices have a major application in assessing vegetation in the presence of smoke, anthropogenic pollution, or volcanic plumes. This was demonstrated by applying the AFRI for a biomass burned forest in Brazil. Limited success of these indices is expected in case of dust due to presence of larger particles that are of similar size to the wavelength and therefore not transparent at 2.1 mum. The AFRIs can be implemented to data from any sensor that has the SWIR bands. Currently, the most commonly used of such instruments are the Landsat - Thematic Mapper (TM) and Advanced Thematic Mapper Plus (ETM+), Moderate Resolution Imaging Spectrometer (MODIS), Advanced Spaceborne Thermal Emission And Reflection (ASTER), and Japanese Earth Resources Satellite - Optical System (JERS-OPS). Although the AFRI2.1 was demonstrated to perform better than the AFRI1.6, the latter still can be used for the same application in conjunction with instruments that have onboard only the 1.6-mum band, such as Systeme Probatoire d'Observation del la Terre (SPOT4) - VEGETATION, Indian Remote Sensing (IRS-1C/D), and Resource-21.

ER - TY - JOUR ID - metternicht2003 AU - Metternicht, G. TI - Vegetation indices derived from high-resolution airborne videography for precision crop management T2 - International Journal of Remote Sensing PY - 2003 SN - 0143-1161 VL - 24 IS - 14 SP - 2855-2877 ER - TY - JOUR ID - moran1997 AU - Moran, M. S. AU - Inoue, Y. AU - Barnes, E. M. TI - Opportunities and limitations for image-based remote sensing in precision crop management UR - http://www.sciencedirect.com/science/article/pii/S003442579700045X DO - 10.1016/s0034-4257(97)00045-x T2 - Remote Sensing of Environment PY - 1997 SN - 0034-4257 VL - 61 IS - 3 SP - 319-346 AB - This review addresses the potential of image-based remote sensing to provide spatially and temporally distributed information for precision crop management (PCM). PCM is an agricultural management system designed to target crop and soil inputs according to within, field requirements to optimize profitability and protect the environment. Progress in. PCM has been hampered by a lack of timely, distributed information on crop and soil conditions. Based on a review of the information requirements of PCM, eight areas were identified in which image-based remote sensing technology could provide information that is currently lacking or inadequate. Recommendations were made for applications with potential for near-term implementation with available remote sensing technology and instrumentation. We found that both aircraft- and satellite-based re-trote sensing could provide valuable information for PCM applications. Images from aircraft-based sensors have a unique role for monitoring seasonally variable crop/soil conditions and for time specific and time-critical crop management; current satellitebased sensors have limited, but important, applications; and upcoming commercial Earth observation satellites may provide the resolution, timeliness, and high quality required for many PCM operations. The current limitations for image-based remote sensing applications are mainly due to sensor attributes, such as restricted spectral range, coarse spatial resolution, slow turnaround time, and inadequate repeat coverage. According to experts in PCM, the potential market for remote sensing products in PCM is good. Future work should be focused on assimilating remotely sensed infonna- tion into existing decision support systems (DSS), and conducting economic and technical analysis of remote sensing applications with season-long pilot projects. ER - TY - ELEC ID - idb AU - Henrich, V. AU - Krauss, G. AU - Götze, C. AU - Sandow, C. TI - The IndexDatabase UR - https://www.indexdatabase.de/ CY - Bonn PY - 2011 DA - 2011 ER -