Title: Area between Peaks Feature in the Derivative Reflectance Curve as a Sensitive Indicator of Change in Chlorophyll Concentration
Eric Ariel L. Salas, Geoffrey M. Henebry
Abstract: Vegetation spectral features can detect chlorophyll concentrations. Two key spectral features evident in the first derivative (FD) of reflectance constitute the two main peaks: one located around 685-705 nm and the other near 710-725 nm. We propose that the area between peaks (ABP) can be used as a sensitive indicator of changes in the photosynthetic pigments at leaf level and demonstrate it using a high-spectral-resolution dataset of maize leaves collected by Gitelson and coworkers (2005). We find significant high positive correlations (r2 > 0.90) between chlorophyll concentrations and both the ABP and its continuum length feature. Read more here.
The Landsat program is a series of earth-observing satellite missions jointly managed by the National Aeronautics and Space Administration (NASA) and the United States Geological Survey (USGS). The first Landsat satellite launched in 1972, and the latest satellite in the series, Landsat 8, provides continuity, as well as improvements, on important global monitoring of our earth.
Landsat 8 was launched February 11, 2013, and contains two sensors. One collects 8-band multispectral imagery at 30-meter resolution, as well as panchromatic imagery at 15 meters. The other collects thermal imagery at 100-meter resolution. The orbit of the satellite results in it capturing 170-by-185-kilometer-sized scenes along a predefined path that returns to the same location every 16 days.
Landsat imagery has significant value in environmental and natural resource studies and research, such as agriculture and forestry. Both governmental and nongovernmental organizations interested in monitoring urbanization or analyzing concepts such as carbon sequestration will also find the continual monitoring of the earth at medium resolution to provide a wealth of information. The education aspects of the services are also boundless.
As with the other satellites, USGS manages the collection of imagery from Landsat 8. Every day, staff receive and process approximately 450 new Landsat 8 scenes. These scenes are available for download at no cost within 24 hours of acquisition. The current archive of Landsat scenes now contains more than four million scenes. Full-resolution, natural-color renderings of these are quickly accessible using LandsatLook, which is powered by ArcGIS for Server.
Landsat 8 Now Available for ArcGIS Online Users
A new set of Landsat 8 services released by Esri provides access to the latest and best Landsat 8 scenes. These services make the valuable Landsat scenes from USGS quickly accessible as multispectral, multitemporal image services that can be used in a wide range of web and desktop applications.
Esri first released Landsat imagery services—more than eight terabytes—to ArcGIS Online users in 2012. These image services made the collection of Landsat Global Land Survey (GLS) scenes spanning the years of 1980, 1990, 2000, 2005, and 2010 accessible as more than 20 dynamic, multispectral, and multitemporal image services. These dynamic services enable a wide range of client applications, such as temporal access to any of the band combinations, as well as products such as Normalized Difference Vegetation Index (NDVI) without the need to download or locally process any data.
For the Landsat 8 services, Esri daily downloads the latest, approximately 300 Landsat 8 scenes and adds them to a set of image services that contain the best and most recent 50,000 Landsat 8 scenes, which require about 60 terabytes for storage. These scenes are hosted on Esri's cloud infrastructure and available for access in different modes.
By default, the user views the best scenes. The best scene is determined using a weighting of cloud coverage and age of the scenes. Users can reorder the scenes based on metadata attributes, lock onto a specific scene, or use a time slider to see how an area changes with time.
Not all scenes are kept; otherwise, the data volumes for storage would continually increase. Instead, older scenes are removed. Typically, the latest four scenes with less than 50 percent cloud coverage are kept, as well as the scene that is nearly cloud free and closest in date to the GLS 2000 scene, so as to aid in longer-term change analysis.
Services can be accessed in web maps but can also be used in a range of applications and ArcGIS for Desktop. A subscription to ArcGIS Online is required to access the services, but there is no charge for usage.
Many Services Available in the Cloud
A number of different image services are served from the same source. The most used is the Landsat 8 Views service. This allows users to view a range of different band combinations including natural color (bands 4,3,2) and color infrared (bands 5,4,3), which highlight photosynthesis in plants. The agriculture band combination (bands 6,5,2) highlights differences in various crop types. The SWIR band combination (bands 7,6,5) provides better penetration for clouds. The bathymetric option (bands 4,2,1) provides better water penetration and is especially useful for coastal applications.
Users can also select any user-defined band combination. The functions can be applied with fixed enhancements or with the Dynamic Range Adjustment Stretch, which requests the server to maximize the contrast so as to get the most out of the extended dynamic range of the sensors.
The Landsat 8 Views service also provides two indexes. The Colorized NDVI provides information on the health of vegetation, while the Colorized Normalized Difference Water Index highlights areas that have high moisture content.
The Pan-sharpened service provides enhanced natural color imagery by sharpening the natural color bands (4,3,2) with the 15-meter panchromatic imagery. The Panchromatic service provides access directly to the panchromatic imagery. Again, the dynamic range adjustment capability ensures that maximum information content is available even when used in web applications.
While all these services return 8-bit rendered versions of different products, the Analytic service enables applications to access the full range of data values that might be required for some analysis applications.
Prototype global monthly and annual WELD 30m products generated from Landsat 5 and 7 data on NASA’s fastest supercomputer were made available for climate year 2010 from the USGS EROS (http://globalweld.cr.usgs.gov/collections/).
This is the beginnings of the global WELD product suite that will provide gridded monthly and annual Landsat 30m information for any terrestrial non-Antarctic location for six 3-year epochs spaced every 5 years from 1985 to 2010.
Source: SDSU GSCE
You may be interested with this recent video from NASA featuring space experts discussing the search for Life in the vast universe.
"NASA space-based observatories are making unprecedented new discoveries and revealing worlds never before seen. During a televised panel discussion of leading science and engineering experts at NASA Headquarters on Monday, July 14, a scientific and technological roadmap to lead to the discovery of potentially habitable worlds among the stars was addressed. The agency's next step, the James Webb Space Telescope (Webb telescope), was featured as a new tool that will continue to help scientists rewrite scientific textbooks long after its scheduled launch in 2018."
Scene Sharp USA will formally introduce the Fuze Go Plugin for ENVI this week at the Esri User Conference in San Diego. The plugin gives ENVI software users access to Fuze Go MS Sharp, an automated multispectral image fusion software which can simultaneously fuse up to 30 spectral bands of data from inside the popular ENVI geospatial processing package.
“The Exelis ENVI software is widely known for its multi- and hyperspectral image processing capabilities and is an ideal platform for geospatial information users to access the automated Fuze Go MS Sharp image fusion software,” said Ian Lucas, President and CEO of Scene Sharp Technologies Incorporated™.
Scene Sharp will demonstrate the Fuze Go plugin for ENVI along with the full line of Fuze Go software products in booth #410 at the Esri User Conference being held July 14-18 in San Diego.
The plugin gives users the option of accessing the Fuze Go MS Sharp software either within the ENVI workflow or outside of it so that fusion can be performed as a stand-alone application. This frees up the ENVI software license for other image processing activities. No GIS or image processing experience is needed to utilize the Fuze Go tools.
Fuze Go is a fully automated technology that enables users to quickly and easily fuse data sets to add color to non-colorized satellite and aerial imagery with just a few mouse clicks. One of its most common applications is pan-sharpening. By colorizing image data, GIS users can visualize and extract richer information content from remotely sensed data to make better informed decisions.
Also at the 2014 Esri UC, Scene Sharp USA will demonstrate the powerful processing capabilities in its Fuze Go SAR Sharp application, which was designed for more effective exploitation of data captured by satellite-based synthetic aperture radar (SAR) sensors. Fuze Go SAR Sharp fuses gray-scale radar data with optical multispectral bands to colorize the SAR data set. An industry first is the “Dynamic Reader” which allows pre-process on the fly viewing of SAR imagery with real time adjustment of color intensity being added to the scene.
Fuze Go MS Sharp and SAR Sharp are available for purchase for an annual license fee. Batch processing versions of the software packages are also offered to perform automatic fusion of multiple optical or SAR scenes.
To learn more about the Fuze Go products, please contact Kevin Marasch at 1-216-901-9800. Please visit www.fuzego.com to try the software at no charge for 15 days.
Esri UK, the B2B mapping and analytics company, has announced a new contest to find Britain’s best story map. The winning entries will win one of five top prizes and feature on Esri UK’s new story map gallery which will launch in the Autumn.
Story maps combine interactive maps and multimedia content to create a unique user experiences. Since the launch of ArcGIS Online, hundreds of organisations have used Esri’s mapping tools to tell their stories and some of the best examples can be found in Esri’s Story Map Gallery.
Esri UK is encouraging potential story mappers to look at the ‘Great British Summer’ for inspiration. From major sporting events to music festivals, seaside holidays to picnics in city parks, there are many great British summer experiences that can be shared on a story map. Alternatively, entrants can submit story maps they have made previously.
To find out more and to enter, please click here.
PCI Geomatics, a world-leading developer of remote sensing and photogrammetric software and systems, the release of Geomatica 2014; the latest version of the company’s complete and integrated desktop image processing software featuring tools for remote sensing, digital photogrammetry, geospatial analysis, map production, mosaicking and more. The release was announced at an exclusive meet and greet that featured presentations and demonstrations of the latest features of the software.
“This release of Geomatica shows PCI’s continued commitment to tools that further simplify a user’s workflow,” said David Piekny, Product Marketing Manager at PCI Geomatics. “It is not uncommon in this industry for users to rely on multiple software packages to complete everyday tasks. New features in Geomatica are designed to allow operators to complete these tasks without leaving the software and interface they are comfortable with, saving time and frustration.”
New features in Geomatica 2014 include: Live DEM Editing, which lets users to see and edit DTM errors on an automatically updated live ortho preview; Smart Geo-fill, which facilitates the retouching of ortho-mosaics while maintaining full geo-referencing, channel combinations and bit-depth; and Python Scripting, which allows for customizable scripting to combine image processing with other tasks to streamline data management applications, generate intelligent business products, or customize output for a variety of GIS applications.
“Geomatica 2014 is an ambitious release, and I expect customers to be very happy with the updates we’ve made,” said Peter Hazlett, Technical Product Manager at PCI Geomatics. “In addition to new tools and functions, we’ve made improvements to key algorithms, added new wizards, and expanded our industry-leading sensor support.”
Geomatica 2014 is available for 64-bit versions of Microsoft Windows (Windows XP/Windows 7/Windows 8/Server 2003/Server 2008/Server 2012) starting today. A Linux version will follow shortly thereafter. For more information on Geomatica 2014, please visit www.pcigeomatics.com/geomatica.