|U.S. Geological Survey
Request for Information 08HQ35-NoSolicitation
Landsat Level-0R Data
The purpose of this Request for Information (RFI) is to determine if there is interest by one or more commercial or non-profit vendors in offering Landsat products beyond those that will be available from the US Geological Survey (USGS). The USGS has available Landsat TM and ETM+ data in a raw, uncorrected format (Level-0R) so that these data could be processed to user specifications (projection, datum, and resampling method).
By February 2009, the U.S. Geological Survey (USGS) will no longer offer any customer-specified Landsat products for sale. By eliminating production, billing, and accounting costs associated with customer-specified products, the USGS will be able to pass these savings on to users in the form of free image data. Landsat scenes processed in a single, standard-product format will be available for user search, selection, and electronic retrieval at no charge via the Internet. These standard products will be derived from newly captured imagery and from the entire USGS Landsat archive. The standard Landsat 7 product, described below, is based on what were previously the most popular customer-specified processing parameters.
The USGS Standard Product for Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data conforms to the following processing parameters:
Product type: L1T (level-1, terrain-corrected: systematic radiometric correction; precision geometric correction; DEM)
Pixel size: 15m/30m/60m
Orientation: North up
Resampling: Cubic convolution
Map projection: UTM (Polar Stereographic for Antarctica)
Output format: GeoTIFF
Media type: FTP Download
DEM: Global Land Survey DEM (SRTM, NED, CDAD, DTED, GTOPO 30)
Schedule for transition to USGS Standard Products:
Landsat 7 ETM+ newly acquired: Currently available (global coverage)
Landsat 7 ETM+ archive: Late September 2008
Landsat 5 TM newly acquired: Early December 2008
Landsat 5 TM archive: Late December 2008
Landsat 4 TM archive: Late January 2009
Landsat 1-5 MSS archive: Late January 2009
This transition began in June 2007 with USGS distribution of free Landsat 7 scenes obtained over North America. The initial user community response has been highly favorable; however, some users may prefer processing options beyond what the USGS will be using. The Landsat product types to be discontinued by the USGS are summarized in Appendix A, and the user-specified processing parameters to be discontinued are summarized in Appendix B.
The USGS Landsat Archive holds data collected worldwide by eight sensors flown on six satellites between 1972 and the present: Landsat 1 Multispectral Scanner (MSS), Landsat 2 MSS; Landsat 3 MSS; Landsat 4 MSS and Thematic Mapper (TM); Landsat 5 MSS and TM; and Landsat 7 Enhanced Thematic Mapper Plus (ETM+). Within each of these satellite/sensor combinations, there are many types of ‘raw ‘(Level-0R) data, especially for MSS data, which has low user demand.
Landsat 4 and 5 TM have two types of Level-0R data: TM-R and TM-A. The TM-R data have had no corrections applied, whereas TM-A data have had radiometric corrections applied. For some of the TM-A scenes there are no corresponding TM-R data available. Landsat 7 ETM+ has the most consistent archive of raw data, although in April 2007, a change on the spacecraft to Bumper Mode dictates an alternate processing method. Also, the ETM+ Scan-Line Corrector (SLC) failed in May 2003, resulting in a 22 percent loss of data per scene. The SLC failure results in duplicated data along the edge of the scene which requires special handling in processing. This is described in an algorithm theoretical basis document found at: (http://landsat.usgs.gov/products_SLCOff_Processing_ATBDV1.1.pdf).
Data acquired prior to May 2003 are often referred to as SLC-on, whereas data from after May 2003 are called SLC-off data. A suite of products for SLC-off data was designed and implemented by the USGS after 2003. In order to apply systematic radiometric or geometric correction to TM and ETM+ data, a processing system must have the ability to ingest and apply a Calibration Parameter File (http://landsat.usgs.gov/images/tools/IAS-207_L7_CPF_Definition_v6-2.pdf) that is provided by the USGS Landsat Project. This file is produced and disseminated quarterly, or on a more regular basis as needed.
Questions for RFI Respondents:
1. Does your company currently have capabilities to process L0R Landsat data to generate Level-1 products to your own specifications?
2. If so, for which instruments?
a. Landsat 1-3 MSS
b. Landsat 4-5 TM
c. Landsat 7 ETM+ SLC-on
d. Landsat 7 ETM+ SLC-off
3. Is there interest in providing custom processing based on L0R data as a service to other users (with the ability to charge fees at your discretion)?
4. If the answer to question 1 is no, is consideration being given to acquiring the hardware, software, and unprocessed (L0R) data in order to generate products to meet user specifications beyond those of the USGS Standard Landsat Products?
5. If so, for which instruments?
a. Landsat 1-3 MSS
b. Landsat 4-5 TM
c. Landsat 7 ETM+ SLC-on
d. Landsat 7 ETM+ SLC-off
6. Would expectations be that the USGS to provide the necessary software for processing L0Rp data to L1G or L1T?
7. If there is interest in acquiring L0Rp data, approximately how many scenes are needed per request, and how frequently?
8. Is it preferred the data to be delivered electronically (FTP) or on media (hard drive)?
Please submit any other information that may be pertinent.
Appendix A Landsat Product Descriptions
L0Rp: Raw Uncorrected. The Level 0Rp (L0Rp) data product provides reformatted raw data with no radiometric or geometric corrections applied. The L0Rp data are World Reference System (WRS) scene-based. Reformatting includes shifting pixels by integer amounts to account for 1) the alternating forward-reverse scanning pattern of the sensor, 2) the odd-even detector arrangement within each band, and 3) the detector offsets inherent to the focal plane array engineering design. The pixels are NOT aligned per scan line. Image data are stored as 8-bit unsigned integer (DN) values. L0Rp data have no map projection or datum assigned. L0Rp data are in the Hierarchical Data Format (HDF).
The SLC-off product includes the original duplicated scan lines along the edge of the scene. The L0Rp SLC-off data product contains alternating areas of duplicated scan lines (14 pixels wide) along the edge of the scene. The width of the duplicated regions gradually diminishes toward the center of the scene. The center of the image contains nominal image data.
L1R: Radiometric Corrected (Level 1R). The Level 1R (L1R) data product is radiometrically corrected L0R data; radiometric calibration has been applied but no geometric corrections have been applied. Scan lines are reversed, but the pixels are NOT aligned per scan line. Image data are not geometrically corrected or geographically referenced and are provided in 16-bit (radiance) values.
L1G: Systematic Correction (Level 1G). The Level 1G (L1G) data have been radiometrically calibrated and corrected; systematic geometric corrections have been applied using data collected by the sensor and spacecraft. The scene will be rotated, aligned, and georeferenced to a user-specified map projection. Geometric accuracy of the systematically corrected product should be within 250 meters (1 sigma) for low-relief areas at sea level. SLC-off products contain the original data gaps, which gradually diminish in width toward the center of the scene. Level 1 processing applies a small (2-pixel) interpolation along the scanline boundary, and all remaining duplicated image data are replaced with null values (zero-fill). The image therefore contains alternating "stripes" of missing data. A scan gap mask is included with the final product.
L1Gt: Systematic Terrain Correction (Level 1Gt). The Level 1Gt (L1Gt) data have been radiometrically calibrated and corrected; systematic geometric corrections have been applied using data collected by the sensor and spacecraft while also employing a Digital Elevation Model (DEM) to correct for relief displacement. SLC-off products contain the original data gaps, which gradually diminish in width toward the center of the scene. Level 1 processing applies a small (2-pixel) interpolation along the scanline boundary, and all remaining duplicated image data are replaced with null values (zero-fill). The image therefore contains alternating "stripes" of missing data. A scan gap mask is included with the final product.
L1T: Terrain Correction (Level 1T). The Level 1T (L1T) data have been radiometrically calibrated and corrected; systematic geometric corrections have been applied using data collected by the sensor and spacecraft. Geodetic accuracy is refined by incorporating ground control points using a Digital Elevation Model (DEM) to correct for relief displacement. Geodetic accuracy of the product depends on the accuracy of the ground control points and the resolution of the DEM. SLC-off products contain the original data gaps, which gradually diminish in width toward the center of the scene. Level 1 processing applies a small (2-pixel) interpolation along the scanline boundary, and all remaining duplicated image data are replaced with null values (zero-fill). The image therefore contains alternating "stripes" of missing data. A scan gap mask is included with the final product.
Gap-filled (Level 1Gt or 1T) (SLC-off only). A gap-filled SLC-off product is a derived product in which all missing image pixels in the original SLC-off image have been replaced with estimated values based on one or more histogram-matched scene(s) from a previous date. The primary (SLC-off) and fill (SLC-off and/or SLC-on) scenes are radiometrically and geometrically corrected using the satellite model and platform/ephemeris information. All images are rotated and aligned to the user-specified map projection. The primary scene is co-registered to the fill scene(s) and all missing image pixels in the primary scene are then replaced with estimated values based on local linear histogram-matched data from the fill scene(s). A scan gap mask is generated for each band of the primary scene, which identifies the original data source for every pixel within the final output product. The delivered data product consists of the final gap-filled image, along with a gap mask (one file per band).
L1T Segment-Based Gap-fill (SLC-off only). This L1T product incorporates a multi-scale segmentation model to fill the gaps in the SLC-off image. The segmentation model is based on terrain-corrected ETM+ SLC-on data from circa 2000. The gaps are filled with the same-day radiometric values using a nearest neighbor algorithm, while maintaining the landscape patterns derived from the segmentation model. Data products include the following parameters:
Pixel Size: 14.25m/28.5m/57m
Output Format: GeoTIFF, FAST-L7A, HDF
Map Projection: UTM
Orientation: North up
Resampling: Cubic Convolution, Nearest Neighbor, Modulation Transfer Function
Appendix B. User-specified Processing Parameters for Level-1 Products
Ordering Parameter Options
Map projection: UTM, SOM-B, ALBERS, LCC, PS, PC, TM, OMA, OMB
Horizontal datum: WGS84, NAD83, NAD27
Resampling method: Cubic Convolution, Nearest Neighbor, Modulation Transfer Function
Scan gap interpolation (SLC-off only): 0 to 15 pixels (default = 2 pixels)
Scan gap interpolation (SLC-off Gap-filled only): Default only (2 pixels)
Image Orientation: Map (north up), Path (satellite/nominal)
Pixel size: 30 meter (30m/15m/60m), 28.5 meter (28.5m/14.25m/57m), 25 meter (25m/25m/50m)
Format: GeoTIFF, HDF (Heirarchical Data Format, v4.1), Fast L7A, NDF (NLAPS Data Format)
Media Delivery Type:
CD, DVD, FTP