.. _gen_scan:

Soil Climate Analysis Network
^^^^^^^^^^^^^^^^^^

Observations of soil conditions from the `Soil Climate Analysis Network (SCAN) <https://www.nrcs.usda.gov/resources/data-and-reports/soil-climate-analysis-network>`_.
The data are obtained from the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) `Air Water Database <https://www.nrcs.usda.gov/wps/portal/wcc/home/dataAccessHelp/webService>`_.


**Dataset Name**: scan

**Data Source**: usda

**Data Collection or Processing Notes:**

    We query data from the Air Water Database, early on Sunday mornings. Each weekly job collects all observations since the date through which we have existing data stored. For sites that are currently in operation, this translates to collecting data for only the previous week (7 days for daily data, 168 hours for hourly data). 

    Note that raw hourly data is saved in UTC while raw daily data is saved with respect to the local site time zone. 

    To maintain the integrity and traceability back to the original sources, our team conducts very limited data manipulation on the queried data. This includes the following:

    - Unit translation into SI units   - Standardization of NaN/missing values

    

Variables
^^^^^^^^^^^^^^^^^^

This describes the available variables of the dataset.
Use the dataset, variables and temporal_resolution in python access functions as described in the Working with Gridded Data, and Working with Point Observations.

.. list-table:: Atmospheric Variables
    :widths: 25 60 30 20 20 20
    :header-rows: 1

    * - variable
      - description
      - temporal_resolution
      - units
      - aggregation
      - 3D
    * - air_temp
      - Air temperature
      - daily
      - c
      - min, mean, max
      - no
    * - precipitation
      - Precipitation
      - daily
      - mm
      - sum_snow_adjusted, accumulated, sum
      - no


.. list-table:: Subsurface Variables
    :widths: 25 60 30 20 20 20
    :header-rows: 1

    * - variable
      - description
      - temporal_resolution
      - units
      - aggregation
      - 3D
    * - soil_moisture
      - Soil moisture
      - daily
      - mm
      - sod
      - yes