Discussion Paper – NWCG GIS Data Layer Standard
AVIATION HAZARDS
May 6, 2011
This document provides assumptions, rationale, clarifications, examples, or background related to the Aviation Hazards data standards.
NWCG Obstacle GIS Data Layer Standard
NWCG AviationActivity GIS Data Layer Standard
NWCG Airport GIS Data Layer Standard
NWCG Jettison GIS Data Layer Standard
The Aviation Hazards data standard includes definition of a series of feature classes for storing information in support of safe fire-related aviation operations. This data will be combined with national datasets (DAFIF, DVOF) to inform aviation operations and create flight hazard maps used for briefing visiting aircrews, pilots, incident management teams, and flight planning for projects and fires. The dataset is not intended for navigational use. The pilot should always obtain an FAA briefing and conduct operations with a "see and avoid" attitude.
General Requirements
-Design must accommodate collection and storage of aviation hazard features
-Define minimum attribution for aviation hazards data for interagency collaboration and data sharing
-Adopt existing or proposed NWCG data standards and valid values
-Create simple design to provide a good user experience for data collection, analysis and cartography
Data Layer Definitions
NWCG Obstacle (point, line, and polygon): These layers capture either man-made or naturally occurring point, line, or polygon physical features that may present a risk to fixed or rotary wing pilots, especially during low-altitude-above-terrain aviation support to emergency incidents within or adjacent to wildland areas. The layer is used to manage features that are not included in DOD or FAA datasets.
NWCG Aviation Activity (point and polygon): These layers capture activities and events that may present a risk to pilots during aviation operations. The distinction between activities and obstacles is that activities have a dynamic characteristic as the hazard may be temporal or seasonal. Examples include parachuting jump sites and agricultural flying and spraying. The layer is used to manage features that are not included in DOD or FAA datasets.
NWCG Airport: This layer captures airports and heliports with basic information about the site.The layer is used to manage features that are not included in DOD or FAA datasets.
NWCG Jettison: This layer captures retardant and water jettison sites.
Other details and guidelines on data content specific to each feature class are described in the Section 4: Discussion of the related GIS Data Layer Standard.
Adopt Existing NWCG Data Standards
The following NWCG Data Standards have been adopted:
-Date
-LandOwner Kind and Category
Domain Values
An attempt has been made to identify valid values (domains; drop down lists) for fields to simplify editing and limit human error.
The following domains have been identified:
Domain / CommentsNWCG_AviationActivityType_PT / See discussion below
NWCG_AviationActivityType_PL / See discussion below
NWCG_AirportType
NWCG_SurfaceType
NWCG_ObstacleType_PT / See discussion below
NWCG_ObstacleType_LN / See discussion below
NWCG_ObstacleType_PL / See discussion below
NWCG_LandOwnerCategory
YesNoUnk
An effort was made to define a comprehensive list of the ‘types’ of aviation hazards (obstacles and activities)that could be used across the United States. The domains were developed through a review of DAFIF, DVOF, and FAA standards and existing datasets to determine the types of features that would be stored in each feature class. Domains from those standards were revised and grouped to simplify the domain list.
The decision to group or eliminate domain values from the initial list was based on:
- Identification of which features a pilot could distinguish visually
- Consideration of features that present a risk during fire aviation operations
- An attempt to simplify the dataset for maintenance purposes.
Domains were further organized to identify which types of features are represented as points, lines, or polygons. Some types of features can be in multiple geometries depending on feature size and representation.
Data Quality – Null Values
The current data model allows null values in all fields in an effort to accommodate loading historical datasets that may not adhere to this data standard. When possible, it is recommended that agencies prohibit null values in required fields to ensure data integrity.
Symbology
A symbol set is in the planning phases and will be made available upon completion.
Symbology requirements are as follows:
- Symbology should be as close as possible to what pilots current use
- Symbology may vary based on scale/altitude
Glossary
DAFIF - Digital Aeronautical Flight Information File
DVOF – Digital Vertical Obstruction File
FAA – Federal Aviation Administration
NWCG – National Wildfire Coordinating Group