4. Data and Metadata Visual Validation

Visual validation consists of evaluating graphical representations of the data and metadata. The different types of graphics and which Auditor evaluates them are shown in the Table 4.1.

Table 4.1 Types of graphics and auditor

Type	Facility	Scientific
Station map	✔	✔
Data availability	✔	✔
Instrument responses	✔	✖
Probabilistic Power Spectral Densities (PPSD)	✖	✔
Waveforms	✖	✔

An auditor in charge of validation visits the A-Node validation web site via a web browser. This auditor moves through pages, each one presenting a plot. If everything looks correct, he/she can validate the plot. If he/she finds a problem in a plot, he/she writes a description of the problem, and may flag it as an error to be corrected.

4.1. Access to the validation website

The validation website is not publicly available. An auditor will receive an email containing a link to the web site. For the security reasons, this link contains a token that will be checked by the site, and there is a limited validity duration.

4.2. Facility and Scientific web validation

There are 2 kinds of web validation: Facility and Scientific. The guide for Auditors can be found in the Web Validation Guide.