Information Content - Detailed Category Descriptions

Data Handling Approaches

There are several ways of handling data loading in the application, each with pros and cons. We anticipate all of the data loading to fall into one of these categories:

1. Bundling Data with App
   • This makes the application download and memory usage bigger and is only good for static data. It has the advantage of having the raw data available to the app for special capabilities.
2. Loading from a Service On-The-Fly
   • This has a smaller overall memory footprint at the expense of more network traffic. It is great for dynamic data. Because data may be reloaded with every change in context (geographic bounding box, altitude, time, etc), it can result in lots of traffic and latency in the user experience.
3. Loading from a Service Once
   • This has an intermediate memory footprint and is also good for dynamic data. All (or most?) of the data for all contexts is loaded at one time, at startup or during execution. 

Essential Information

CeilingVisibility (Gridded and Feature Product)

Ceiling and Visibility are available as an observed point variable in METARs, as a forecasted point variable in TAFs, and as a gridded variable from the Ceiling Visibility and Analysis (CVA) product, produced at NOAA's Aviation Weather Center, visible on ADDS, and distributed by the National Weather Service's (NWS) Satellite Broadcast Network (NOAA-Port). The point observations and forecasts are generally available every hour, though they may be upgraded more frequently. The gridded product is produced every 5 minutes and available in GRIB format. Gridded values are continuous across the conus land mass.

Ceiling and Visibility are important to pilots because they determine the airports which are available for takeoff and landing (depending on pilot and aircraft certification) and impact the airspace into which they can safely fly. Pilots need this information in preflight as well as updates enroute.

METAR data is available in 3 forms: as raw text from NOAA, as WXXM from CSS-Wx WFS servers, or as XML, CSV, or binary from the ADDS DataServer.

Airport Location (Feature in-app or as service?)

Airport locations are obtained from the FAA 56-day update FADDS data. They are important to pilots as situational awareness variables, allowing them to determine the proximity of plotted weather phenomena to their departure/destination/alternate or route.

Airport locations could be provided to an app as a static dataset, updated regularly with the application, or as a live service from an operational AIXM service or the ADDS DataServer. Due to the mixed nature of this data, XML and custom formats may be the best exchange model.

Winds

Winds are available at various altitudes from the ground (as METARs and TAFs) up through the atmosphere (as modeled winds and FA winds aloft), both as an observed/current speed and direction and forecasted speed and direction. The FA winds are only provided at specific locations, but they are derived from virtual soundings through the model data. Winds determine takeoff and landing direction and safety, fuel consumption en route, and can be used to infer meso-scale atmospheric disturbances. The most important use of winds for pilots seems to be at takeoff and landing, especially for rotorcraft.

Wind data can be obtained as a gridded dataset in MDV from ADDS, in NetCDF from CSS-Wx WCS-RI at NCAR, or as GRIB from the NWS. Winds aloft could be derived from these datasets or obtained in text form from the AWC.

Storms (turb, front, convection, ice)

Storms are a supercategory for several aviation hazards, including icing, turbulence, gust fronts, and wind shear. These are usually expressed as an area of varying levels of hazard, which must be interpreted for its impact based on the aircraft type, pilot experience, and passenger comfort.

Storm information typically comes from weather models (RAP, CIP/FIP, GTG, and CoSPA), but may also be human-generated vector products, in the case of fronts. The fronts will be more difficult to process/display. Gridded storm data could be thresholded and/or reduced to low/med/high hazard areas.

NOTAMs (Optional for HEMS pilots)

NOTAMs are used in flight planning and pre-flight to determine areas where the pilot can't fly or land. These are informational products that should not change often, so, with some exception, they are not needing to be actively presented to the user unless the user seeks them out. No alerting is anticipated for these.

NOTAMs are difficult to obtain. Until recently, they were only on the FAA PilotWeb and TFR sites. ADDS now ingests NOTAMs and makes them available via the Text DataServer. This could be leveraged for this product.

Icing

Icing is arguably similar in nature to the "Storms" content above. It is an indication of an aviation hazard. Data are available as grids from an hourly model run including an analysis (CIP) and a forecast (FIP).

Precip Type

Precip Type is of concern primarily near the ground (for takeoff and landing) and for low-altitude flights like HEMS. It affects visibility, icing, and runway adhesion. There are three sources of this information: METARs/TAFs, radar observations, and model analysis/forecast. The METARs/TAFs are more relied upon because they are observation-based or human-generated, but radar and model-based precip type information has the potential to fill in gaps between stations and provide a more temporally and spatially-consistent data.

Desirable Information

Radar

Radar data can provide insight into summer convection, storm strength, and storm fronts. The most beneficial radar products are the lowest level reflectivity (using either the Base Reflectivity or the NSSL Hybrid Scan Reflectivity) and the total reflectivity through the vertical column (using the Composite Reflectivity). Update rate is the of primary importance and users seemed to like these products as much for their timeliness as for what information they impart about the weather.

Precip Rate

The precipitation rate can be an indication of storm strength and is often used in IFR conditions to determine the severity of obscuration. It is a model-derived field present in the WRF-RR.

Runway Conditions (Optional for HEMS pilots)

Aviation Obstructions (Essential for HEMS pilots)

Cities and Towns (Essential for HEMS pilots)

Navigation Fixes/Routes

Lightning

Terrain

Weather Cameras

Airport Layout (Optional for HEMS pilots)

Turbulence

Dew Point

Sunrise/Sunset/Moon (Essential for HEMS pilots)

Temperature

Highways/Roads/Streets (Essential for HEMS pilots)

Optional Information

Satellite

Lakes and Rivers

Airport Services

Moonrise/Moonset (Essential for HEMS pilots)

NWS Text Area Forecasts

Counties

NWS Text Forecast Discussions