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Supported Formats

Uploading Data

The spectral library allows upload of any type of file. However, for the system to extract metadata, or plot spectra contained in a file, it must be uploaded in one of the supported upload formats.

Data Preparation

Currently it is necessary to name your files with the correct file extension, so that it can be identified by the system. i.e., if you want to upload FILE.001 which is an ASD format file, then you should name it FILE.001.ASD

Upload Data Formats

General Purpose Formats:

  • SPU (file extension: spu)
    • The SPU data format is a binary data format generated by UNISPEC instruments. It is capable of storing both data and metadata within a single file.
  • ASD (file extension: asd)
    • ASD is a binary data format developed by Analytical Spectral Devices, Inc. and used by some of their spectrometers. It can be used for recording spectral data, and the metadata associated with those readings.
  • ENVI (header file extension: hdr, data file extension: '' -, i.e., none )
    • "ENVI uses a general raster data format consisting of a simple flat binary file and a small associated ASCII (text) header file". The header file can be parsed for metadata independent of the binary data file; however, the spectra contained in the data file cannot be extracted without the presence of the corresponding header file. ENVI header files should be named with the '.hdr' extension, while the data files should use the same filename, without any extension. For example: SAMPLE1.hdr and SAMPLE1, comprise an ENVI format header and data file.
  • 2 column whitespace seperated data (file extension: prn)
    • This is a simple ASCII (text) data format. It is used for storing data rather than metadata. The file format is 2 column, whitespace seperated. i.e, each point in the plot corresponds to a single row in the data file. Each row of the data file consists of two numeric values seperated by whitespace. Currently files using this format should be named with the file extension prn.

Specialized formats:

  • ASTER (associated file extensions: spectrum.txt, ancillary.txt)
    • The ASTER 2.0 spectral library was used as prototype data source for the GeoChronos Spectral Library Management Tool. The ASTER library contains 'spectrum.txt' files that contain both data and metadata, so in order to demonstrate the versatility of our library, we have included a parser for these files. The library also contains 'ancillary.txt' files which are automatically associated as ancillary data to the corresponding 'spectrum.txt' file.
  • VSL (file exntensions: spu, html)
    • The Vegetation Spectral Library was also used as a prototype data source for the GeoChronos Spectral Library Management Tool. This library contains spu files which are parsed in the same manner as any other SPU file uploaded to the system, however a special parser was written to extract additional metadata from the html descriptions (field notes) of the samples.
  • GEOCHRONOS (file extension: .geochronos)
    • The geochronos format was developed at the request of the PIs working with the GeoChronos project. This is a comma-seperated-value (csv) based format that allows the user to describe a large number of spectral samples or records using a spreadsheet. The format can be used to store both data and metadata about the samples. More details about the GeoChronos format can be found here

Downloading Data

The vision for the GeoChronos project is that scientists will be able to use the tools in the portal to do most of their work online. However, in some instances they might need to download the data and work offline.

Any files uploaded to the portal can be downloaded again for work offline. The portal does not modify the original data files. It parses the metadata from the files where possible, and allows the user to edit that metadata, but it does not rewrite the original files. If you want to change the metadata and work with the new metadata offline, then you will need to export the records and the new metadata.

Exporting Data

Exporting data allows the user to create a new file that contains any modifications to the metadata associated with a spectral record. It can be used to output a single spectral record, or a larger set of data. The exported metadata and spectra are output in the GeoChronos format described in greater detail here.

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Last updated 720 days ago by Roger Curry