changelog.txt

ENVISAT产品C语言读取程序

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   CHANGELOG for the EPR-API, VERSION 2.0.1
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*** Changes from Version 2.0 to Version 2.0.1 (of 21.03.2003) ***

    1) Bugfix: The build-in support for older MERIS L1b/L2 products (IODD 5)
       caused that no other product types than MERIS L1b/L2 data products could
       be opened. The error message was "epr_create_band_ids: band not found".
       Now also the other MERIS, AATSR and ASAR products can be opened again.

*** Changes from Version 1.4 to Version 2.0 (of 07.03.2003) ***

    1) The operational ENVISAT MERIS Level 1b product format has slightly changed.
       The 'spectral shift index' has been replaced by a 'detector index' according
       to IODD 6.0 (PO-TN-MEL-GS-0003).
       The older format is still supported by the EPR-API.

    2) The DDDB as such has been removed and merged into the files 'epr_dddb.c'
       and 'epr_dddb.h'. This makes it unnecessary to pass the DDDB path to epr_init_api().
       The API therefore has become easier to maintain.

    3) The computation of geolocation has been improved and adapted to the VISAT precision.

*** Changes from Version 1.3 to Version 1.4 ***

    1) Support for ENVISAT ASAR data products added

*** Changes from Version 1.2 to Version 1.3 ***

    1) Function epr_get_field_elem_as_mjd has been changed, it has now only
       one parameter left:
       const EPR_STime* epr_get_field_elem_as_mjd(const EPR_SField* field)

    2) Getter functions for dataset descriptions have been added to the API
         o epr_get_num_dsds
         o epr_get_dsd_at

*** Changes from Version 1.1 to Version 1.2 ***

    1) All functions defined in "epr_api.h" now properly return exeptional
       values in case of an error.

    2) Some of the API function did not clear the internal API error state.
       All public API functions now clear the global error state before
       the execute their actual code.


*** Changes from Version 1.0 to Version 1.1 ***


    General
 =============

 1) The 'epr_open_product' function now creates automatically all dataset and 
    band identifiers found in a given ENVISAT product file.
    That means, the user must not take care of the memory de-allocation of these 
    identifiers; this will automatically be done when the 'epr_close_product' 
    function is called.

 2) In addition eight functions have been implemented. Their purpose is to ease 
    the work with dataset and band identifiers.
    The new functions are listed below.

 3) The "epr_dataset.h" header-file has been added.

   New Functions
 ================

   /* Gets the number off all datasets contained in a product. */
   uint epr_get_num_datasets(EPR_SProductId* product_id);

   /* Gets the dataset_id at the specified position within the product. */
   EPR_SDatasetId* epr_get_dataset_id_at(EPR_SProductId* product_id, uint index);

   /* Gets the dataset_id coresponding to the specified dataset name. */
   EPR_SDatasetId* epr_get_dataset_id(EPR_SProductId* product_id, const char* dataset_name);
 
   /* Gets the name of the dataset for the given dataset ID. */
   const char* epr_get_dataset_name(EPR_SDatasetId* dataset_id);


   /* Gets the number off all bands contained in a product. */
   uint epr_get_num_bands(EPR_SProductId* product_id);

   /* Gets the band_id at the specified position within the product. */
   EPR_SBandId* epr_get_band_id_at(EPR_SProductId* product_id, uint index);

   /* Gets the band_id corresponding to the specified name. */
   EPR_SBandId* epr_get_band_id(EPR_SProductId* product_id, const char* band_name);

   /* Gets the name of the band for the given dataset ID. */
   char* epr_get_band_name(EPR_SBandId* band_id);

   Deprecated Functions
 ========================

   'epr_create_dataset_id' is no longer part of the public API. 
   Please use 'epr_get_dataset_id' instead.

   'epr_free_dataset_id' is no longer part of the public API. 
   The dataset IDs retrieved with the 'epr_get_dataset_id' function
   do not require an explicite destruction.


   'epr_band_dataset_id' is no longer part of the public API. 
   Please use 'epr_get_band_id' instead.

   'epr_free_band_id' is no longer part of the public API. 
   The dataset IDs retrieved with the 'epr_get_band_id' function
   do not require an explicite destruction.