Quality control (Maritime Charting)

Data quality is regulated by a quality assurance (QA) program through quality control (QC) processes. QA is an all-encompassing management approach that combines technical aspects of quality, qualitative methods, and human resources in a system designed to meet the customer's expectations. QC is an individual task or set of tasks performed at a given level of the production process aimed at ensuring the integrity of a product, output, or action.

QC does not have a prescribed time in the production process other than as a last step before data delivery. However, this does not mean that's the first time QC is performed. QC can be performed in process and at any time during production. Some QC is inherent in the database and occurs on the fly, such as attribution with domains, while other processes must be applied such as minimum feature detection and visual data validation. Early detection and feedback are essential in successfully producing high-quality, cost-effective data.

Domains

Part of the geodatabase design is defining attribute domains. Domains control allowable attribute values, which facilitate feature attribution and on-the-fly QC. Domains are not a quality control task. They control the allowable inputs to a field and are therefore implied quality control.

Data rendering

The features in the layers may be rendered in several ways to facilitate feature extraction, attribution, and quality control. Layers are rendered with random symbols that may include subtypes if the feature class has them. Within the properties of a feature class, specific attributes can be used to assign symbols to features. This can be very useful for ensuring feature attribute consistency.

Label expressions

The two most common label tools are available on the Nautical DNC toolbar. They both display attribute fields in the upper right corner of the feature and modify the feature symbol. These label tools should be used when you want to view these attributes on-screen or to create a quality control plot.

The Label SoundP Layers tool labels your Hydrographic Depth (HDP) or Hydrographic Drying Height (HDH) fields based on the Sounding Category (SND) value. It displays numbers to one decimal, rounding 0.25 and 0.75 to the next higher single decimal.

The Label BotcharP Layers tool labels your bottom characteristics based on the following field order, from left to right: Physical Surface Characteristics (PSC), Material Composition Category (MCC), Secondary Material Characteristics (CSM), Material Composition Secondary (MCS), Underlying Material Characteristics (UMC), and Material Composition Underlying (MCU).