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ActionsFederal Mapping Programs Fact Sheets
The following Fact Sheets provide summary information on the primary national mapping programs that are tracking, developing, and/or sharing geospatial data. This information is available to support the Regions and the RMCs as they conduct regular planning and project management activities.
In addition, this coordination supports successful relationships that are needed between the Regions/RMCs and other State and Federal personnel.
Programs identified here are not static. New data is being added to the national inventory every month. Future efforts and planned projects are constantly being updated. Therefore, it is appropriate to review national programs as well as local data sources in order to obtain the most current data available.
The programs detailed here include:
- National Digital Orthophoto Program (NDOP)
- National Elevation Dataset (NED) and Similar USGS Holdings
- National Agriculture Imagery Program (NAIP)
- NRCS/USDA Geospatial Data Gateway
- US Census MAF/TIGER Accuracy Improvement Project (MTAIP)
- National Geospatial-Intelligence Agency (NGA)
- NOAA Coastal Services Center
Each of the data development programs listed here focuses on the specific needs of their end users. However, they all have potential applications for Flood Map Modernization.
FEMA Map Modernization serves critical roles in both the development of accurate data and the coordination of geospatial activities and progress of those activities. Understanding and participating in these programs will help achieve the goal of the National Spatial Data Infrastructure (NSDI), which is to build a physical, organizational, and virtual network that is designed to enable the development and sharing of this nation's digital geographic information resources.
National Digital Orthophoto Program (NDOP)
Program Highlights
Data Product
- 1 meter resolution black and white orthophotography nationwide
- High resolution (usually 1 foot) natural color (some black and white) orthophotography in selected urban areas
- High resolution (finer than 1 meter) orthophotography for some States
Advantages
- 1 meter data is available nationally
- All these data meet FEMA accuracy specification
- Uncompressed imagery provides the maximum visual quality
- Source of orthophotos if local or state data is not available
- Urban area orthos are very recent
- Accessible through the Seamless Data Distribution System (http://seamless.usgs.gov)
Disadvantages
- High resolution data in urban areas more difficult to manipulate due to file size
- Much of the 1 meter data is several years old
- Full resolution quarter quad tiles also are difficult to manage compared to compressed mosaics of same imagery available from USDA
- Limited areas are fairly poor quality or Color-Infrared photography which is not as visually pleasing
Program Overview
The National Digital Orthophoto Program (NDOP) was chartered in 1993 as a consortium of Federal agencies with the purpose of developing and maintaining national orthoimagery coverage in the public domain by establishing partnerships with Federal, State, local, tribal, and private organizations.
Data Details
Nationwide DOQs are black and white (B/W), natural color, or color-infrared (CIR) images with 1-meter ground resolution.
High resolution (usually one foot) imagery is available for the Nation's largest urban areas and state capitals. The imagery usually is natural color.
USGS also has agreements in which it distributes statewide high resolution imagery for some states.
Data Applicability to Flood Mapping Program
All these data meet FEMA's accuracy specifications and could be used as base maps for DFIRMs if the image quality is acceptable.
Data Availability
Data status for high resolution imagery can be found at http://seamless.usgs.gov/website/seamless/products/listofortho.asp. USGS is developing a new capability to display the status of one-meter DOQs.
Data Ordering
In the Seamless Data Distribution System at http://seamless.usgs.gov, users specify the footprint of the data they require. The data are in GeoTIFF format, UTM coordinate system, NAD 83. Up to 1.6 gigabytes of data (transmitted in 100 megabyte units) can be downloaded for free in one request; through multiple requests, users can download more data for free. If a single request exceeds the 1.6 gigabyte limit, the system offers the option of providing the data on media for a fee to cover processing, handling, and mailing.
In the past, the USGS produced three types of tiled DOQs which may also be used:
- 3.75-minute (quarter-quad) DOQs are available in both Native and GeoTIFF formats. DOQs in native format are cast to the Universal Transverse Mercator (UTM) projection and referenced to either the North American Datum (NAD) of 1927 (NAD27) or the NAD of 1983 (NAD83). DOQs in GeoTIFF format are cast to the UTM projection and referenced to NAD83. The average file size of a B/W quarter quad is 40-45 megabytes, and a color file is generally 140-150 megabytes. Quarter-quad DOQs are distributed on CD-ROM, DVD, 8-mm tape, and File Transfer Protocol (FTP) as uncompressed files. Software is available that will convert a DOQ image from Native to GeoTIFF format in either NAD27 or NAD83 (download from http://rmmcweb.cr.usgs.gov/software/).
- 7.5-minute (full-quad) DOQs cover an area measuring 7.5-minutes longitude by 7.5-minutes latitude. Full-quad DOQs are mostly available for Oregon, Washington, and Alaska. Limited coverage may also be available for other states.
- County DOQs consist of collections of individual DOQs that have been compiled on a county-by-county basis. There is fairly good coverage for counties in Kansas, Georgia, Minnesota, North Carolina, and Pennsylvania. Other states may also have limited counties available. The files are cast to the UTM projection and referenced to either NAD27 or NAD83. County DOQs are packaged as individual JPEG-compressed 8-bit binary files on CD-ROM.
The tiled DOQQs are searchable and orderable from EarthExplorer at http://edcsns17.cr.usgs.gov/EarthExplorer/. DOQs are available from EROS Data Center (http://edc.usgs.gov/products/aerial/doq.html) on DVD, CD, 8 mm tape, and via FTP (download). County DOQs are available only on CD, and typically require multiple CDs per county.
National Elevation Dataset (NED)
Program Highlights
Data Product
- 1 arc second (30 meter) posting DEM
- 1/3 arc second (10 meter) posting DEM
- 1/9 arc second (3 meter) posting DEM
Advantages
- Most edge matching/seam issues from quad based DEMs have been fixed
- 1/3 arc second NED provides very close fidelity to quad contours
- Avoids many of the problems in original 30 meter DEMs. Good enough for A zone mapping.
- 1/9 arc second data generally good enough for detailed study
- Newer 1/3 and 1/9 arc second data increasingly are from LIDAR and other high-resolution data sources.
Disadvantages
- 1 arc second NED based on many sources with variable quality. Generally not suitable for hydraulics or floodplain mapping
- 1/3 and 1/9 arc second data not available everywhere, though 1/3 arc second covers nearly half of CONUS.
- 1/3 arc second quality varies based on original quad contour interval
- Small areas of 1/3 arc second data is resampled 1 arc second data and low quality. Generally occurs at state boundary where 1 arc second state and 1/3 arc second state appear on same quad tile. Area of 1 arc second state will be resampled data.
Program Overview
The USGS National Elevation Dataset (NED) has been developed by merging the highest-resolution, best quality elevation data available across the United States into a seamless raster format. NED has a consistent projection (Geographic) and elevation units (meters). Nationwide coverage is available for data at a 1 arc second (30 meter) post spacing; there also is substantial coverage at 1/3 arc second (10 meter) post spacing. The horizontal datum is NAD83, except for AK, which is NAD27. The vertical datum is NAVD88, except for AK, which is NAVD29. NED is a living dataset that is updated bimonthly to incorporate the "best available" DEM data. As more 1/9 arc second (3 meter) post spacing data covers the US, then this will also be added to the seamless dataset.
Data Details
NED is designed to provide National elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections were made in the NED assembly process to minimize artifacts, perform edge matching, and fill sliver areas of missing data. NED has a resolution of one arc-second (approximately 30 meters) for the conterminous United States, Hawaii, Puerto Rico and the island territories and a resolution of two arc-seconds for Alaska. NED data sources have a variety of elevation units, horizontal datums, and map projections. In the NED assembly process the elevation values are converted to decimal meters as a consistent unit of measure, NAD83 is consistently used as horizontal datum, and all the data are recast in a geographic projection. Older DEMs produced by methods that are now obsolete have been filtered during the NED assembly process to minimize artifacts that are commonly found in data produced by these methods. Artifact removal greatly improves the quality of the slope, shaded-relief, and synthetic drainage information that can be derived from the elevation data. NED processing also includes steps to adjust values where adjacent DEMs do not match well, and to fill sliver areas of missing data between DEMs. These processing steps ensure that NED has no void areas and artificial discontinuities have been minimized. The artifact removal filtering process does not eliminate all of the artifacts. In areas where the only available DEM is produced by older methods, then "striping" may still occur.
(The following information about the accuracy of the NED is from Maune, D., (ed,), 2007, Digital elevation model technologies and applications: the DEM users manual (2nd edition), chapter 4. Courtesy of Dean Gesch, USGS.)
The accuracy of the NED varies spatially because of the variable quality of the source DEMs. As such, the NED inherits the accuracy of the source DEMs. In an effort to provide more information to users on the vertical accuracy of the NED, the data set has been tested by comparing it with an independent reference source of very high accuracy. The reference data are the geodetic control points that NGS uses for gravity and geoid modeling. The overall absolute vertical accuracy expressed as the root mean square error (RMSE) is 2.44 meters. As better sources of data are incorporated, the accuracy improves.
For some applications of elevation data, the relative, or point-to-point, vertical accuracy is more important than the absolute vertical accuracy. Whereas absolute accuracy accounts for the combined effects of systematic and random errors, relative accuracy is a measure of just random errors. Averaged over all 9,187 point pairs, the relative vertical accuracy is 1.64 meters.
One caveat to note about the accuracy assessment presented here is that even though the reference control point data set is large, the number of quadrangle-based USGS DEMs on which the points are located is relatively small. Thus, if users have a need for very specific accuracy information for the NED for a local area, a separate assessment should be done with suitable reference data just for that area.
Data Applicability to Flood Mapping Program
- 1/3 arc second data provides very close fidelity to quad contours and is acceptable for Risk Class C (see MHIP Section 7.0 for definition of Risk Class C).
- 1/9 arc second data is generally good enough for detailed study.
Data Availability
The data dictionary, release notes, and update information can be found at ftp://edcftp.cr.usgs.gov/pub/data/ned/.
Information about the best resolution available and methods of production are available through the USGS GISDATA Map Studio Interactive Viewer at: http://gisdata.usgs.net/website/usgs_gn_ned_dsi/viewer.htm. The following figure illustrates the resolution of data available on March 12, 2007:
An additional source for elevation data that has potential utility for Map Modernization is the Center for LiDAR Information Coordination and Knowledge (CLICK). Some of the available data resulted from a LiDAR investment that supports FEMA flood map modernization and can be found at the CLICK website http://lidar.cr.usgs.gov/index.php.
Data Ordering
In the Seamless Data Distribution System at http://seamless.usgs.gov/, users specify the footprint of the data they require. Up to 1.6 gigabytes of data (transmitted in 100 megabyte units) can be downloaded for free in one request; through multiple requests, users can download more data for free. If a single request exceeds the 1.6 gigabyte limit, the system offers the option of providing the data on media for a fee to cover processing, handling, and mailing.
National Agriculture Imagery Program (NAIP)
Program Highlights
Data Product
- County level and Quarter Quad orthophotography
- 1 meter or 2 meter available (more detail below)
- Many areas captured using digital sensor
Advantages
- Often more recent than NDOP DOQs
- Compression for 2005 and 2006 NAIP has been reduced which may increase usability for FEMA base map
Disadvantages
- Imagery is acquired during peak growing season; may not be suitable for areas with heavy “leaf on” conditions
- 2 meter data not acceptable for FEMA base map
- 2002-2004 County Mosaics compression degrades visual quality substantially
- Occasional clouds in images
Program Overview
In 2002, the USDA started the NAIP to support the continued development of their own GIS program through the acquisition of digital orthophotography. This imagery, when used in conjunction with other land and customer information already available, provides the ability to effectively administer farm programs, and georeference natural disasters and animal or plant disease outbreaks to support better decision making. The program's goal is to acquire imagery annually over large parts of the contiguous 48 states, and deliver it to users within a few months time frame. In order to support agriculture analysis, imagery is captured during the peak growing seasons (June-August).
Data Details
There are two primary data products that are developed and available through NAIP. These include the Compressed County Mosaic (CCM) and the Full Resolution Quarter Quad Tiles (QQ). Both the CCM and QQ are available in 1 or 2 meter resolution, depending on the priority of the project area and availability of contributing partner funds.
Because the imagery is captured during peak growing season, this "leaf on" status is likely to obscure some ground level features, especially in heavily treed areas. This should be an issue to consider based on the geography of the region under consideration. All data comes with a full suite of FGDC compliant metadata for documentation.
Compressed County Mosaic (CCM)
The CCMs are developed for the convenience of full county coverage. In many contexts, it is easier to manipulate a single, full county file than multiple, smaller DOQQs. This can reduce the costs for management of data and increase production efficiency. These are useful when larger geographic coverage is required. Compression for 2005 and 2006 NAIP is MrSID MG3 at a ratio of 15:1 which may increase usability for FEMA base maps. 2004 and earlier NAIP remain at higher compression ratios in MrSID MG2 and therefore have limited use for FEMA base maps.Full Resolution Quarter Quad Tiles (QQs)
The QQ is the full resolution standard delivery product. The QQ can be a better format when smaller geographic areas are concerned as they cover an area measuring 3.75-minutes longitude by 3.75-minutes latitude, or approximately 2.5 miles on each side. The DOQQ format is GeoTIFF.Digital Sensors
In some cases, vendors use digital cameras for an entire state. In a fully digital workflow it can be very efficient for vendors to retrieve the raw imagery for other uses. It may be possible to negotiate with the vendors to produce high quality elevation for targeted areas using these data. Because the data is already acquired, this may be a practical way to obtain small areas of quality elevation for high risk areas.
Data Applicability to Flood Mapping Program
1 meter data is acceptable for FEMA base maps provided vegetation does not obscure roads or other important ground features. This imagery is more recent than NDOP DOQs, but 2 meter data and highly compressed county mosaics are not acceptable for FEMA base maps.
Data Availability
The following states have 1 meter imagery acquired in 2006 available:
- Alabama (Digital)
- Arkansas
- Connecticut (Digital)
- Delaware (Digital)
- Iowa
- Kansas (Digital)
- North Carolina
- New Jersey (Digital)
- Nevada (Digital)
- New York
- Tennessee (Digital)
- Utah (Digital)
- Washington
- Wyoming (Digital)
The following states have 1 meter imagery acquired in 2005:
- California (digital)
- Colorado
- Maryland
- Michigan (digital)
- Montana (digital)
- North Dakota (digital)
- Oregon
- South Carolina (digital)
- Wisconsin
The following states have 1 meter imagery from 2004 available:
- Idaho (digital)
- Kentucky
- Louisiana (partial)
- Mississippi (partial)
- Ohio
- Pennsylvania
- South Dakota
- Texas (digital)
- Utah (partial)
See http://www.fsa.usda.gov/FSA/apfoapp?area=home&subject=maps&topic=landing for more information.
Data Ordering
For more information call (801) 975-3500. To order NAIP imagery, visit
NRCS/USDA Geospatial Data Gateway
http://datagateway.nrcs.usda.gov/GatewayHome.html
Program Highlights
Data Product
- The Geospatial Data Gateway provides One Stop Shopping for natural resources or environmental data
- Source for USDA Countywide Compressed Orthophoto Mosaics
Advantages
- Data downloads are free and near-real time
- Compressed, mosaiced counties are easier to work with, color/tone balanced, and potentially more accurate than individual quarter quad NDOP DOQs
Disadvantages
- Compression of imagery may degrade visual quality
- County mosaics generally use first generation NDOP imagery so they are fairly old.
- USDA is not the authoritative source for all data on the site, so some data may be out of date
Program Overview
The Geospatial Data Gateway is intended to provide a single access point for resource data. It provides a way to easily locate data that exist for selected geographic areas, find the types of data for that area, and deliver the data packaged in formats compatible with commercial and USDA Service Center application formats.
One major purpose of the Gateway is to support the development, presentation, and dissemination of information by Service Center field staff working in the field with customers away from the office. However, the public has access to the Gateway to find and retrieve resource data.
Data Details
The data sets served by the Gateway are primarily determined by the USDA Service Center Geographic Information System (GIS) Strategy. The data themes are listed on the Gateway Data Management page Gateway Data Management page http://datagateway.nrcs.usda.gov/data.html. This page also identifies non-geospatial data that may be available through the Gateway.
By using the FGDC metadata standards, the Geospatial Data Gateway can serve data to Federal Clearinghouse nodes and become a node itself for those layers for which the USDA is the steward.
Data Applicability to Flood Mapping Program
County orthophoto mosaics can be used as FEMA base maps provided the compression does not reduce the usability of the image. These mosaics are much easier to work with, have more consistent image brightness, contrast and sometimes improved positional accuracy compared to the first generation tiled DOQs.
Data Availability
The Geospatial Data Gateway provides access to many different data layers, which may be updated as frequently as once per week. The most critical themes are generally available nationwide.
Critical Themes
- Orthoimagery
- Soils
- Common Land Unit (CLU)
Data Ordering
Data is available for order online at http://datagateway.nrcs.usda.gov/NextPage.asp. Users can download the data from the website directly, retrieve it from an FTP site, or order it on CD or DVD.
US Census MAF/TIGER Accuracy Improvement Project (MTAIP)
http://www.census.gov/geo/www/tiger/index.html
Program Highlights
Data Product
Street centerline files with road names and address ranges for geocoding
Advantages
- Realigned files accurate enough to use as FEMA base map
- Smaller, often easier to work with than orthophotos
- Vector based maps can be easier to read
- Beginning in the Fall of 2007, TIGER spatial data will be available in shapefile format
Disadvantages
- Program extends from 2004 to 2008. Entire country not yet available.
- Some communities may prefer orthophotos
- TIGER/Line files may still contain features that have not been realigned to more accurate source data
Program Overview
The US Census Bureau is realigning the street features in a portion of the nation's counties or statistically equivalent entities each year until all counties are completed in 2008.
Data Details and Availability
The U.S. Census Bureau has continued to release realigned TIGER/Line files twice a year. The 2006 Second Edition TIGER/Line files are the second of two versions of the TIGER/Line files that contain updated 2006 geographic boundaries
The 2006 Second Edition TIGER/Line files cover 1,949 counties and county equivalents. A listing of these counties can be found below.
Data Applicability to Flood Mapping Program
Realigned files accurate enough to use as FEMA base map.
Data Ordering
Data is available directly from the US Census website. Currently, the 2004 TIGER/Line Files are available online in ASCII format and are free to download.
In addition, you can purchase the files on CD-ROM or DVD from the Customer Services Center at (301) 763-INFO (4636).
2006 First and Second Edition TIGER/Line Files
The Census Bureau has realigned street features in the counties or statistically equivalent entities listed below as part of the MAF/TIGER Accuracy Improvement Project (MTAIP) using sources with a horizontal spatial accuracy of circular error 95 (CE95) at 7.6 meters or better. Information about the source and the horizontal positional accuracy of that source appears in the county-based metadata included as part of each compressed 2006 Second Edition TIGER/Line file. The 2006 Second Edition TIGER/Line Technical Documentation has further information on the use of Record Type M to determine the spatial accuracy for any individual line segment.
For a complete listing of the 2006 First and Second Edition TIGER/Line Files, please refer to the file, "Census MAF/TIGER Accuracy Improvement Project (MTAIP)," which can be downloaded from the "Related Links" section at the top of the page.
National Geospatial-Intelligence Agency (NGA)
Program Highlights
Data Product
High resolution LIDAR of select urban areas
Advantages
- Very high accuracy, density
Disadvantages
- Coverage is generally small areas in urban cores
- Some processing is required to ensure proper bare earth model for flood study
Program Overview
NGA has a goal to collect LIDAR over major urban areas in the U.S. There is not consistent funding, so future collections are unpredictable.
Data Details and Availability
There are limitations for the use of the data. NGA will make the data available to FEMA and FEMA contractors working on a flood study. However, the data can be used for flood studies only and not distributed to anyone else or used for other purposes.
See FEMA's current Geospatial Data Coordination Report at www.hazards.fema.gov "Tools & Links" page for a list of elevation and orthoimagery data sets that NGA has collected that are in areas covered by upcoming flood studies.
Data Applicability to Flood Mapping Program
These data meet FEMA’s terrain mapping requirements for all risk classes.
Data Ordering
To order data, contact Alan Lundy-Ponce at (703) 317-6520 or alan.lundy-ponce@mapmodteam.com.
NOAA Coastal Services Center
Program Highlights
Data Product
- LIDAR data collected by NOAA and other agencies, such as the U.S. Army Corps of Engineers Joint Airborne LiDAR Bathymetry Technical Center of Expertise, in swath along most of U.S. coast.
- Historical shoreline data with the average accuracy of measured benchmarks at 3.06 m (10 ft), which meets the NOAA guidelines for fixed aids to navigation and objects charted as landmarks
Advantages
- LIDAR data covering most of the coast generally have sub-meter vertical and horizontal RMS error
- Shoreline data larger scale than USGS shoreline data
- Data can be downloaded for free in user's choice of vertical datum and projection
Disadvantages
- Elevation data in narrow strip along coast only
- Not all of the US coastline has been mapped
- Shoreline data is dated with no update schedule provided
Program Overview
The NOAA Coastal Services Center is an office within the National Oceanic and Atmospheric Administration devoted to serving the nation's state and local coastal resource management programs. The Center, with its partnerships, is acquiring high-resolution topographic data through remote sensing technologies. The primary goal is to work with the coastal resource management community and help practitioners by supplying information or data on topographic issues.
Data Details and Availability
These data are generated through both private sector contracts and in-house efforts. The remotely sensed data sets were created from LIDAR information. The collected LIDAR data are typically targeted at a narrow strip of coastline and are usually a kilometer or less in width. The vectorized shoreline data were created from scanned historical shoreline maps in raster format and are in decimal degrees, referenced to the NAD83 datum. The accuracy of the shoreline datasets is more strict than national standards and four times the accuracy of current U.S. Geological Survey 1:24,000 scale topographic maps. This means that the original T-sheets can be assumed to also meet NOAA guidelines and to be very accurate in their depiction of the shoreline that existed at the time of the surveys. As well, access to shoreline data from a variety of other sources is available through the use of a 'links' page. The data from this site are considered public information and may be distributed freely.
Data Applicability to Flood Mapping Program
Most LIDAR data adheres to FEMA's terrain specifications for mapping floodplains (http://www.fema.gov/plan/prevent/fhm/dl_cgs.shtm). The metadata records for each LIDAR data set should be reviewed prior to use on a FEMA project to ensure sufficient accuracy for the project. Some LiDAR data sets also include precise near shore bathymetry. Due to the historical nature of the shoreline data, each dataset should be examined for its potential use with FEMA projects.
Data Ordering
These data are available directly through the Costal Services Center website at http://www.csc.noaa.gov/crs/tcm/.