April Shimitz
Computer Services Branch
Software Engineering Department
May 21, 2001
Signatures
Prepared by: | |
April Shimitz | |
Software Engineer, | |
Raytheon, ITSS | |
Concurred by: | |
Tim Beckmann | |
Software Project Lead, | |
Raytheon, ITSS | |
Approved by: | |
Charles Larson | |
Project Manager, | |
Raytheon, ITSS |
Document History
Number | Date and Sections | Notes |
1 | May 21, 2001 | Document created |
2 | ||
3 | ||
4 | ||
5 | ||
6 |
Unlike most of the LAS ingest applications, MODIS2LAS will not contain the code that performs the actual image data processing. Instead, it makes use of the MODIS Reprojection Tool (MRT), a product of Raytheon ITSS and the South Dakota School of Mines and Technology, and TRANSLAS, an existing LAS application. The MRT is used to convert the MODIS data product file(s) to a set of binary files, one file for each SDS requested for processing, and an associated header file. TRANSLAS is then used to complete the image processing by converting the flat binary files to a LAS image product. See Scope/Limitations Section for a brief outline of the implementation strategy that will be used for MODIS2LAS.
1. MODIS Data Product Descriptions
1.1.2 Each comment may be up to 120 characters in length.
1.1.3 The default value is NULL.
1.1.4 Up to 3 comments may be supplied for multi-volume imagery (TBD - depending on if MODIS data is ever multi-volume).
1.2.2 The file name can be up to 120 characters in length.
1.2.3 The default value is NULL.
1.2.4 This is a required field for processing (TBD - depending on if there can be multiple images on a CD/DVD).
1.2.5 Only one input file name will be allowed.
1.2.6 The name of the INFILE and its path will be specified in either TAE or host (UNIX) format.
1.2.7 The MRT will validate the file name. An invalid file name will cause the MRT to exit with a fatal error, in which case MODIS2LAS will exit with a fatal error.
1.3.2 Since MODIS data consists of 36 spectral bands, the potential exists that a data product could contain all 36 bands. Therefore, a maximum of 36 SDSs may be specified for ingest. The user should specify which SDSs to ingest by the number assigned to each by the MODISSDS tool (MODISSDS requirements).
1.3.3 The default value is NULL.
1.3.6 The MRT will validate the specified SDSs. If the user specifies an SDS number that is not present in the given data product, the MRT will ignore it and generate a warning to notify the user of such action.
1.4.2 This parameter will allow the user to specify up to 36 groupings for the bands.
1.4.3 The values for this parameter will be the number of bands from the BANDS list specified in Section 1.3 to group together into a single product. For example, an array of values (2,4,3) would mean that the first two bands in the list from Section 1.3 go into one output product, the next four bands go into another output product, and the last three bands go into a different output product.
1.4.4 The sum of all the values in this field must add up to the total number of bands specified in the BANDS parameter.
1.4.5 The default for this field is NULL.
1.4.5.2 If NBANDS is left at its default and the number of output file names equals the number of bands, then each band will be output to each different output file.
1.5.2 The user can specify this window in one of four different units (defined in Section 1.6).
1.5.2.2 If the units are degrees/minutes/seconds, then the window is specified as the upper left latitude, upper left longitude, lower right latitude, and lower right longitude.
1.5.2.3 If the units are degrees, then the window is specified as the upper left latitude, upper left longitude, lower right latitude, and lower right longitude.
1.5.2.4 If the units are projection units, then the window is specified as upper left Y, upper left X, lower right Y, and lower right X in meters.
1.5.2.5 When processing multi-resolution imagery, the highest resolution spectral band will be assumed for line/sample values. In essence, an equal-area will be processed across the different resolution bands, that area being determined by applying the specified line/sample values to the highest resolution band.
1.6.2 The units that will be supported are degrees (DEG), degrees/minutes/seconds (DMS), line/sample (LS), and projection units (PRO).
1.6.3 This field is used if the window field in Section 1.5 is specified.
1.6.4 The default for this field is line/sample (LS).
1.6.5 TAE will validate the value, allowing only the following values to be accepted: DEG, DMS, LS, PRO.
2.1.2 Each output file name can be up to 120 characters in length.
2.1.3 This is a required field for processing.
2.1.4 One file name will need to be specified for each output product.
2.1.5 This field will support up to 36 output file names.
2.1.7 The current working directory will be used to output the files and to place all temporary files created by the application, unless a directory path is specified by the user.
2.1.8 All output bands with the same resolution will be placed in the same output file, unless the user has specified other band groupings. If processing multi-resolution imagery, an "_r#" will be appended to the output file name to create the multi-resolution output file names (reference requirement 5.1.1).
3.1.2 If a fatal error occurs and $DELFLG is set to "NO", then any files created by this application will not be deleted.
5. This application must be able to process multi-resolution data.
6.1.1.2 "_i*2" will be appended to the output file name for 16-bit signed integer data.
6.1.1.3 "_i*4" will be appended to the output file name for 32-bit signed integer data.
6.1.1.4 "_r*4" will be appended to the output file name for 32-bit float data.
7.2 The method of processing from CD/DVD is yet to be determined since the format of the data on those media is yet to be formalized.
8.2 Even though the MRT supports 8-bit signed and 16-bit and 32-bit unsigned integer data, since these data types are not supported by LAS, attempts to ingest SDSs that are in any of these data types will cause a fatal error.The application will check if any of the user specified SDSs to ingest are in an unsupported data type as early in the processing as is possible to prevent unnecessary processing from being done.
9.2 Number of samples will be retrieved from the NSAMPLES array. This DDR field is critical.
9.3 Number of bands will be set to the number of bands specified by the user. This DDR field is critical.
9.5 Projection code will be set to Integerized Sinusoidal (ISIN, 31).
9.6 The zone code will be set to 62 and flagged invalid since it is not relevant to the ISIN projection.
9.7 Datum code will be set to the MODIS spheroid (31).
9.8 Projection parameters will be retrieved from the PROJECTION_PARAMETERS field.
9.9 Corner coordinates will be retrieved from the UL_CORNER_LATLON, UR_CORNER_LATLON, LL_CORNER_LATLON, and LR_CORNER_LATLON fields.
9.10 Projection distance will be retrieved from the PIXEL_SIZE field.
9.11 Projection units will be set to meters.
9.12 Line and sample increments will be set to 1.
9.13 Master line and sample will be set to 1.
9.14 Each band's maximum intensity value will be retrieved from the MAX_VALUE field.
9.15 Each band's minimum intensity value will be retrieved from the MIN_VALUE field.
9.16 Data source will be set to "TERRA-MODIS" for each band.
9.17 Sensor name will be set to the name of the SDS each band was generated from.
9.18 Capture direction will be left blank for each band.
9.19 Acquisition date will be retrieved from the header file, though the field name is not yet known since the MRT is currently being enhanced to include this information in the header file.
9.20 Acquisition time will be retrieved from the header file, though the field name is not yet known since the MRT is currently being enhanced to include this information in the header file.
10.2 The output files will be checked for existence and a fatal error message issued in the case that the file already exists.
MODISSDS is a support routine for MODIS2LAS that will query the specified MODIS data product and generate a numbered list of the SDSs present. It will classify each SDS as supported or unsupported, providing a short reason why it does not support processing each SDS indicated as such. The intent is that the user run this application prior to running MODIS2LAS to determine the SDSs available for processing and to assign each a number by which to specify it for ingest in the BANDS parameter of MODIS2LAS.
13.1.2 The file name can be up to 120 characters in length.
13.1.3 The default value is NULL.
13.1.4 This is a required field for processing.
13.1.5 Only one input file name will be allowed.
13.1.6 The name of the INFILE and its path will be specified in either TAE or host (UNIX) format.
13.1.7 An invalid file name will cause a fatal error.
Band # | SDS Name | Supported/Not Supported | Reason |
1 | QC Flags | Not Supported | 32-bit unsigned integer data type not supported by LAS |
2 | Solar Zenith Angle | Supported | |
3 | Viewing Angle | Supported | |
4 | Relative Azimuth | Supported | |
5 | State Flag | Not Supported | 16-bit unsigned integer data type not supported by LAS |
14.1 The "Band #" is the number that should be used in the BANDS parameter of MODIS2LAS to specify the SDSs to process. MODISSDS will number the SDSs according to the spectral order for the type of data product given; these are outlined on the MODIS web site (see Referenced Document 1).
14.2 MODISSDS will also print the SDS information to a file for user reference.
There will be a number of intermediate files created by the MRT, including a log file generated by the MRT, a header file, and a data file for each SDS being processed. The flat files will need to be grouped for ingest by TRANSLAS according to common resolution and data type.
ACRONYMS
DAAC | Distributed Active Archive Center |
EDC | EROS Data Center |
HDF-EOS | Hierarchical Data Format-Earth Observing System (a specialized form of NCSA's HDF format) |
LAS | Land Analysis System |
MODIS | Moderate-Resolution Imaging Spectroradiometer |
MRT | MODIS Reprojection Tool |
NCSA | The National Center for Supercomputing Applications |
SDS | Scientific Data Set |
TAE | Transportable Applications Environment |