CAMS

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h1. Working with the database

The feature database is CAMS managing the storage and access of vector data, pieces of information like sensor measurements that can be described in space with a geometric figure such as a points, lines or polygons. See http://wiki.gis.com/wiki/index.php/Vector_data_modelto read more about vector data models.

The basic piece of information of this data model is the _feature_, defined by a _geometry_ that indicates unequivocally its position and shape in the world, and a set of _attributes_ which are the characteristics associated to that location. Related features sharing a common geometry definition and attribute set are usually grouped together.

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h2. Data model

The CAMS database model is takes inspiration from the _OGR data model_ and the _OGC OpenPackage specification_.

h3. Dataset

A dataset is encompasses a set of feature collections stored in the same database or file.

h3. Collection

A collection describes the characteristics of features of the same kind or category. I.e.: "Wind", "UAV state", "Liquid water content", etc. It corresponds roughly to a table in a relational database or a layer in many geographic information models.

A collection is defined by the following parameters:

# A computer id (name_id),

# A human-readable name,

# An coordinate reference system as an "EPSG code":https://en.wikipedia.org/wiki/EPSG_Geodetic_Parameter_Dataset,

# A geometry type (As of 12/2020 only the "point" geometry is supported),

# A ordered set of attributes and corresponding types. Attributes can be of type _int_, _str_, _float_, or _datetime_.

# And, optionally, a long description.

h3. Feature

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The collection field is used to identify the collection to with a particular field belongs; thus determining the geometry and attribute set. 

General attributes, *t* (time) and *producer* , are mandatory for features generated repeatedly by UAV sensors. The time attribute is represented by a date and time (datetime.datetime in python) in Coordinated Universal Time (UTC). The producer attribute is a string.

Specific attributes are unique to a particular collection. All features of the same collection must have the same attributes, but features of different collections do not need to share specific attributes unlike general ones. For instance, a _"wind"_ collection can have the _"east"_ and _"west"_ attributes to describe the wind vector components.

h2. Code architecture

h3. Class diagram

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h3. DataServer

h3. FeatureDatabase

h3. StorageBackends

h2. Code examples

h3. Initialization

h3. Inserting feature

h3. Querying the database

h2. Post-mission analysis