This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. William Frament, USDA Forest Service (Northeastern Area State and Private Forestry, Durham, NH) acquired color infrared, stereo pair 1:8,000 scale aerial photography for digital orthorectified photomosaics of Gateway National Recreation Area on December 17, 2002, during leaf-off conditions. Hoffman and Swinburne islands of the Staten Island Unit were excluded from this air photo coverage, and thus excluded from the vegetation map. Frament scanned the aerial photographs at 600 dpi and delivered the scanned image files, in TIFF format, and the hard copy photographs to North Carolina State University (NCSU). The photographs, the camera calibration certificate, and a shapefile of photo centers provided by Frament are stored in the archive that NCSU maintains for the NPS Northeast Region Inventory & Monitoring Program.

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. During the planning and coordination phase, CTI staff reviewed all available existing digital imagery for its potential use as the base-map for the vegetation mapping at AMIS. The most promising and easy to access was the data catalog found on the Texas Natural Resource Information System (TNRIS) website. Navigating to the orthoimagery-statewide web page, the list of existing imagery covering AMIS included multiple products produced annually by the U.S. Department of Agriculture’s National Aerial Imagery Program (NAIP). The corresponding NAIP 2010 1-meter (pixel resolution) quarter-quad datasets for AMIS were downloaded and used during the preliminary planning and mapping stages. Since 2012, other orthoimagery covering AMIS was made available on TNRIS and was downloaded by CTI. These included the 2012 and 2016 versions of the NAIP 1-meter quarter quads and the 2015 Texas Orthoimagery Program (TOP) 50-cm quarter quads (Figure 13). All contained an infrared band and the NAIP 2016 product was determined useful for supplying the most up-to-date vegetation patterns (especially in the dynamic inundation zone and other recently disturbed sites) and as an ancillary dataset if needed for hard to view canyons and within shadows along the river bluffs. Overall the 2015 TOP product was found to be superior to the 2016 NAIP imagery due to its finer resolution and higher contrast. The 2015 TOP imagery was then selected and used as the primary basemap for the remainder of the mapping efforts.

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. During the planning and coordination phase, CTI staff reviewed all available existing digital imagery for its potential use as the base-map for the vegetation mapping at AMIS. The most promising and easy to access was the data catalog found on the Texas Natural Resource Information System (TNRIS) website. Navigating to the orthoimagery-statewide web page, the list of existing imagery covering AMIS included multiple products produced annually by the U.S. Department of Agriculture’s National Aerial Imagery Program (NAIP). The corresponding NAIP 2010 1-meter (pixel resolution) quarter-quad datasets for AMIS were downloaded and used during the preliminary planning and mapping stages. Since 2012, other orthoimagery covering AMIS was made available on TNRIS and was downloaded by CTI. These included the 2012 and 2016 versions of the NAIP 1-meter quarter quads and the 2015 Texas Orthoimagery Program (TOP) 50-cm quarter quads (Figure 13). All contained an infrared band and the NAIP 2016 product was determined useful for supplying the most up-to-date vegetation patterns (especially in the dynamic inundation zone and other recently disturbed sites) and as an ancillary dataset if needed for hard to view canyons and within shadows along the river bluffs. Overall the 2015 TOP product was found to be superior to the 2016 NAIP imagery due to its finer resolution and higher contrast. The 2015 TOP imagery was then selected and used as the primary basemap for the remainder of the mapping efforts.

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. Throughout the entire interpretation process, October 1988 CIR photographs were also viewed to better determine vegetation types. The 1988 photos, because they effectively captured fall colors in leaf canopies, were very helpful in revealing various distinctions not apparent on the 1995 and 1996 photographs. The primary characteristic that differed was that of color. Where changes in the vegetation occurred between the two sets of photographs, only characteristics on the recent set were used to determine the types.

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. Throughout the entire interpretation process, October 1988 CIR photographs were also viewed to better determine vegetation types. The 1988 photos, because they effectively captured fall colors in leaf canopies, were very helpful in revealing various distinctions not apparent on the 1995 and 1996 photographs. The primary characteristic that differed was that of color. Where changes in the vegetation occurred between the two sets of photographs, only characteristics on the recent set were used to determine the types.

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. Sanborn Mapping Company, Inc. acquired color infrared, stereo pair, 1:12,000 scale aerial photography for a digital orthophoto mosaic of GARI on March 27, 2003, during leaf-off conditions. The aerial photographs were delivered to the NPS, quality checked, accepted as provided, and sent to NCSU. Upon receipt at NCSU, the aerial photographs were counted to make sure that none were missing, scanned and saved in TIFF format, and placed in the data archive that NCSU maintains for the NPS Northeast Region Inventory & Monitoring Program. Associated data and information provided by Sanborn Mapping Company, Inc. that are also stored in the data archive include the airborne global positioning system (GPS) and inertial mapping unit (IMU) data files, the camera calibration certificate, and a digital flight index map.

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. Sanborn Mapping Company, Inc. acquired color infrared, stereo pair, 1:12,000 scale aerial photography for a digital orthophoto mosaic of GARI on March 27, 2003, during leaf-off conditions. The aerial photographs were delivered to the NPS, quality checked, accepted as provided, and sent to NCSU. Upon receipt at NCSU, the aerial photographs were counted to make sure that none were missing, scanned and saved in TIFF format, and placed in the data archive that NCSU maintains for the NPS Northeast Region Inventory & Monitoring Program. Associated data and information provided by Sanborn Mapping Company, Inc. that are also stored in the data archive include the airborne global positioning system (GPS) and inertial mapping unit (IMU) data files, the camera calibration certificate, and a digital flight index map.

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. The initial base map layers were developed using the 2 m resolution color aerial orthophotos, since they had the highest spatial resolution. The regions were designed on their shared physiography: Eastside, Westside, Riverside, USFS, and Tsankawi sub-units. The vegetation map was developed using a combination of automated digital processing (supervised classifications and image segmentation) and direct image interpretation of high-resolution color and color infrared aerial orthophotography in combination with satellite imagery (Landsat Thematic Mapper).

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. The initial base map layers were developed using the 2 m resolution color aerial orthophotos, since they had the highest spatial resolution. The regions were designed on their shared physiography: Eastside, Westside, Riverside, USFS, and Tsankawi sub-units. The vegetation map was developed using a combination of automated digital processing (supervised classifications and image segmentation) and direct image interpretation of high-resolution color and color infrared aerial orthophotography in combination with satellite imagery (Landsat Thematic Mapper).

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. Several imagery datasets were available for the mapping project. Table 7 lists the types of imagery used in the LEWI mapping project, including the date the imagery was produced and the source of the data. Landsat satellite imagery was acquired from GLOVIS (http://glovis.usgs.gov/). SPOT 4 imagery was downloaded from EarthExplorer (http://edcsns17.cr.usgs.gov/NewEarthExplorer/). Landsat imagery at 30 m resolution consists of 7 bands: 3 visible, 2 mid-infrared, 1 shortwave infrared and 1 thermal band. SPOT 4 imagery consists of 4 bands: 2 visible (10m), 1 shortwave infrared (10m), and 1 mid-infrared (20 m). Imagery used was from the summer 2008 (Landsat) and late fall 2010 (SPOT 4) to provide a phenological contrast useful in differentiating vegetation types. Every homogeneous vegetation type has a unique reflectance which is referred to as a signature. This unique signature is often more apparent and distinct in the infrared wavelengths outside of the human eye visible spectrum, enabling a remote sensing expert to use these unique satellite signature snapshots in time to differentiate various vegetation types.