# Telemetry Metadata File

The telemetry metadata file is a new convention that was conceived
during the MOMA project. Its main purpose is to store metadata about a
telemetry file. However, its purpose may be extended in the future to
include post processed data and perhaps other information. The original
goal was to provide the ability to distinguish between the various
instrument models. In other missions the file extension was used to
determine the model, but after the patch file mechanism was adopted we
lost this capability.

All versions will have their GSE metadata stored in the **gse** key.
This allows us to easily add/remove/modify top level keys without
breaking backwards compatibility and to also differentiate between items
that are not necessarily GSE metadata.

## Versions

### Version 2 

#### Fields 

All fields from version 1 are carried over.

*New*

-   **default_mcal** - The default mass calibration file that should be
    used to calibrate the science data. The mcal file should exist in
    the TID. In the rare case that it does not exist, MOMA Data View
    will attempt to use a different mcal file in the TID. If none
    exists, then it will attempt to copy one from the default mcal
    location. All other applications should quit with a message
    indicating the mcal file was missing in order to avoid misleading
    the user.

#### Example 

```json
{  
  "gse":{  
     "default_mcal": "2015-01-01-00.00.00-identity.mcal",
     "mission":"moma",
     "model":"etu",
     "patch_files":[  
        "m1",
        "m2",
        "m3"
     ],
     "tid":534,
     "tid_dir":"2015-09-29-13.46.05-00534-",
     "tmfile_name":"tm.mom.m1.m2.m3",
     "version":1
  }
}
```

### Version 1 

#### Fields 

-   **mission** - Defines the mission for this data
-   **model** - Defines the model of the instrument that this telemetry
    data was generated with. The model key is used to differentiate
    between things that may differ between the various models, such as
    the default mcal location or the SEB DAC table. The model\'s
    corresponding entry in the 699config.ini file can be found by
    combining the mission and model like
    `<MISSION>`\_`<MODEL>`. For example, for the MOMA
    mission and ETU model, its group in the 699config.ini file would be
    MOMA_ETU.
-   **patch_files** - This list defines the patch files that should be
    applied after the default database is loaded. They should be applied
    in the same order they are listed. The current convention is the
    corresponding patch file for a patch can be found in the TMDef
    directory and is in all caps with the \".txt\" suffix. For example,
    for the m1 patch file, the text file can be found at
    *momagse/TMDef/M1.txt*
-   **tid** - The test ID for this data
-   **tid_dir** - The original TID directory that was generated
-   **tmfile_name** - The telemetry file\'s name. This key can be used
    to determine the name of the telemetry file. If the telemetry
    file\'s name changes, this key should be updated.
-   **version** - The version of the format

#### Example 

```json
{  
  "gse":{  
     "mission":"moma",
     "model":"etu",
     "patch_files":[  
        "m1",
        "m2",
        "m3"
     ],
     "tid":534,
     "tid_dir":"2015-09-29-13.46.05-00534-",
     "tmfile_name":"tm.mom.m1.m2.m3",
     "version":1
  }
}
```