HEMS Tool Tutorial

HEMS Tool Tutorial

This section provides information on effectively using the HEMS Tool. The following topics are covered:

Related Information

HEMS Tool Display

This screenshot points out important features of the HEMS Tool:
Figure 1: HEMS Tool screenshot

HEMS Tool components:

  • Menu Bar - Drop down menu to access all features and configure display.
    • Weather - Weather images that overlay the base map.
    • Overlays - Weather products (point, polygon) that overlay the weather imagery plus an array of maps and features (nav aids, etc).
    • View - Set up default views.
    • Configure - Configure various data plots.
  • Display Time - The time the display is valid for. The data displayed time sync to this time. This also displays a time slider to move the display time back into the past six hours or into the future 6 hours.
  • Fullscreen - Allows the display to go full screen and back.
  • Zoom - Allows the user to zoom in and out on the display.
  • Primary Display - The primary area where weather imagery and data overlays will display.
  • Scale - Map scale showing rough distances on plot.
  • Nav Aid distance - If Nav Aids are visible, this will show the distance and direction to the nearest navigation aid.
  • Lat, Lon - This shows the latitude and longitude of where the cursor is positioned.
  • Legends - Graphical legend for pertinent data shown on the display.
  • Weather Colorbar - This shows a color bar for the weather imagery.

Base Maps

The HEMS Tool has a selection of six base maps. Three use the ESRI base maps and 3 simpler base map selections. The default is the ESRI terrain base map but you can also select a road and satellite view from ESRI and a light and dark NASA blue marble background. These are configurable from the "Configure" drop down.

Figure 2. Base map configuration

Weather Data

Weather products in HEMS are divided into two groups. The first are graphical in nature. These are various weather images and are shown under the weather menu. This includes satellite and MRMS radar images, ceiling and visibility data from the CVA product, icing data from CIP and FIP and temperature, relative humidity and wind speed products from the RAP model. The satellite, radar and one other weather product can be displayed simultaneously. Visibility can be controller by adjusting the opacity of each layer through the configuration menu.

Satellite imagery is available in either 10km infrared and water vapor or 5km visible. The latest image available for the display time is used.

Figure 3. Infrared satellite image

Radar imagery from the MRMS data is displayed as a loop of 5 images ending in the latest available time. The loop is over 40 minutes.

Figure 4. MRMS Radar display

The other weather images are displayed and a color bar below the display area can be used to determine the meaning of the colors.

Figure 5. Flight Category weather display

The CIP/FIP and RAP model data can be displayed at various AGL levels from 1000' to 5000'.

Figure 6. Weather level selection

The display will also label the data being displayed.

Figure 7. Weather level selection

Weather Overlays

In addition to weather imagery, the HEMS Tool offers several weather overlays. This is primarily point data (METARs, TAFs, PIREPs, along with a variety of polygon data (SIGMETs, CWAs and G-AIRMETs). METARs display using the standard station model (see Fig. 4). Clicking on the METAR site will bring up a box with the latest METAR text. If a decoded METAR is desired, that can be set up through the Configure menu (see below).

Figure 8. METAR display
TAFs can be displayed by using the time slider to move the display time into the future.

The Flight Category plot shows colored dots for each METAR reporting site. Like with the METAR display, these will show the flight conditions from the TAFs when the time slider is moved into the future.

PIREPs are displayed using the standard symbols for icing and turbulence. Clicking on the symbol will also display a box with more information on the PIREP including the raw text.

Figure 9. PIREP display

SIGMETs, CWAs and G-AIRMETs are displayed as polygons. The boundaries of the warnings and advisories are in red for SIGMETs, black for CWAs and various other colors for G-AIRMETs. Clicking on the polygon will bring up a box with more information on the advisory including the raw text.

Figure 10. SIGMET display

G-AIRMETs display as one layer which can be rather cluttered. Individual types of G-AIRMETs can be toggled on and off via the Configure menu. Most G-AIRMETs are polygons such as turbulence and icing. The freezing levels are shown as lines. Areas of multiple freezing levels are shown as a light blue polygon with the level range shown in the label.

Figure 11. G-AIRMET display

Also, NWS Hazards are included. These are thunderstorm warnings, tornado warnings, winter storm warnings and other watches and advisories. By default all warnings and advisories are shown. The polygons are color coded by type of hazard and a 2 letter descriptor is used as a label. For example: TS=thunderstorm, TO=tornado, WS=winter storm, FF=flash flood.

Figure 12. NWS Hazard display

Finally, wind barbs from the RAP model can be displayed. These match up with the level selected with the weather imagery. These are derived from wind information at each gridpoint from the RAP model. The wind barbs are filtered to eliminate clutter. More barbs will display as the display is zoomed in.

Figure 13. RAP Windbarb display

Map Overlays

In addition to weather overlays, many non-weather overlays are available. The highway layer displays major highways, interstates in the US. The roads layer shows US, state and local roads with more detail being added as the map is zoomed in.

The Nav Aids layer will give you major navigational aids. More will display as the map is zoomed in. A nearest nav aid to the cursor will display in the lower right. In fig. 14, the cursor is located 47 statute miles ENE of the Maples VORTAC.

Figure 14. RAP Windbarb display

The Airports layer will display all airports and heliports from the FADDS 56 day update. Airports will have small airplanes inside the circle and heliports will have an H. Each icon can be clicked for more information.

Figure 15. Airport and heliport display

Panning and Zooming the Map

The map can be panned using the mouse. By clicking the left mouse button in the display area and moving it, the map will pan. One the mouse button is release, the data will refresh to the new display area. On a tablet, touching the display area and dragging will pan the map.

There are several ways to zoom in and out. The +/- buttons in the upper left corner of the display area can be used. Also, if the mouse has a scroll wheel, it can be used to zoom in and out depending on the direction the wheel is moved. On a tablet, pinch zooming is available. Finally, by holding the shift key while pressing the left mouse button, a zoom region can be selected. A red box will display and once the mouse button is release, the closest region to the zoom box will be displayed. Since OpenLayers uses an integral zoom level with each level being twice the magnification, exact zooms are not possible.

Saving Views

Once a particular desired location is set, the position and zoom level can be saved in the View menu. There are 4 selectable "User" views available. Select which one to use and enter descriptive text in the Name box and hit Save (see Fig. 16). This will save the view for future use.

Figure 16. Setting user views

There are three preset user views for contiguous US (CONUS), Alaska and Hawaii.

Note: User views are set in browser cookies so they are only stored on the browser you created them on. Each browser will have to be set up separately.

Time Controller

The time display and slider is available in the upper right portion of the display. The time display will always show the current valid time for data in the display. By hovering over the time display, a time slider will appear (see Fig. 17). Moving the slider to the right will move forward in time up to 6 hours. Moving the slider to the left will move backward in time up to 6 hours. A "Cur" button is available to quickly return to current conditions.

Figure 17. Time display and time slider

All data are synchronized to the time slider. For example, moving back in time will reset valid times for METARs, SIGMETs, G-AIRMETs, etc. Weather images will also display analyses valid for the new valid time including satellite imagery, CIP/FIP and RAP data. The radar loop will reset to show the latest 40 minutes of radar data in a loop terminating in the valid time.

If the time is moved forward, the display will now show forecasted data. At this time, there is no forecast satellite, radar and CVA data so those layers will turn off. But METARs will be replaced with TAFs and CIP with FIP and RAP analyses with forecasts.

Full Screen Mode

The display can be rendered to full screen mode using the full screen button in the upper right part of the display. The menu bar will remain at the top of the screen but the rest of the display will now cover the full screen. Pressing the full screen button again will return the display to normal view.

Configuring Specific Weather Overlays

METARs

The configure menu offers the ability to change the METAR display.

Figure 18. METAR/TAF configuration
  • Each parameter in the station model plot can be turned on and off. A quick "All" or "None" button is available to toggle on or off all parameters. If a single parameter is desired, it will be plotted at the station location. If more than one, those will plot in their normal locations in the station model.
  • The "Density" setting relates to how many METARs will be displayed at any time. A priority scheme is used for progressive display of METARs. The higher the zoom level, the more stations will plot. But the density for a particular zoom level can be changed through the density setting. Going to +1 will roughly double the number of stations in the plot. Going to -1 will cut the number in half.
  • The Scale setting will scale the data icon on the screen. In some cases, a larger icon is desired. A setting of 1.5 will scale the station model up by 50%.
  • The Decoded METAR toggle will cause the data displayed in the popup box to show a decoded METAR rather than the raw METAR text.
  • The Include TAF toggle will add the latest valid TAF to the popup display.

Flight Category

The configure menu offers the ability to change the Flight Category display.

Figure 18. Flight Category configuration
  • The "Density" setting relates to how many flight category sites will be displayed at any time.
  • The VFR setting will toggle on and off those sites that are under VFR conditions to eliminate clutter.

PIREPS

The configure menu offers the ability to change the PIREP display.

Figure 19. PIREP configuration
  • The turbulence and icing PIREPs can be selectively displayed.
  • An altitude range for PIREPs can be set. This way the PIREPs outside of the flight altitudes can be filtered out. For the HEMS Tool the top altitude is preset to 12,500' to eliminate high altitude PIREPs that of no concern to low level operations.
  • The age of the PIREPs can be set. By default, the latest 90 minutes of PIREPs up to the valid time are displayed.
  • The minimum intensity of the PIREPs can also be set. This way the user, if needed, can select only moderate to severe PIREPs for display.
  • The scale factor of the icons can be set for easier viewing.

SIGMETs

The configure menu offers the ability to change the SIGMET display.

Figure 20. SIGMET configuration
  • The various types of SIGMETs can be toggled on and off. The convective includes US convective SIGMETs and international thunderstorm related SIGMETs. Turbulence includes MTW (Mountain Wave) and LLWS (Low level wind shear) SIGMETs. IFR includes dust and sand storm as well as mountain obscuration SIGMETs.and icing PIREPs can be selectively displayed.
  • The show heights option will add the range of heights for the SIGMET to the label. This can add extra clutter so it is off by default.

G-AIRMETs

The configure menu offers the ability to change the G-AIRMET display.

Figure 20. G-AIRMET configuration
  • The various types of G-AIRMETs can be toggled on and off. All the G-AIRMET types are on by default to show an overview but it is likely only specific G-AIRMETs such as LLWS or icing will be desired.

Hover

By default, features on the display have to be clicked on to show the popup information boxes. This is done to support mobile devices that don't support a hover feature. By toggling hover on, the features will automatically show the popup when the mouse is moved over them.

Browser Cookies

The current state of the HEMS Tool is saved in a set of browser cookies so that a return to the HEMS Tool will recover some of the user settings. These include:

  • hemstmapinfo - This saves the current center latitude, longitude, and zoom level for the display.
  • hemstmapbase - This saves the type of basemap being used (terrain, satellite, light, etc).
  • hemstmapover - This saves a list of the map overlays being used (highways, navaids, etc).
  • hemstdata - This saves a list of weather data layers being displayed (rad, metar, sigmet, etc).
  • hemstwx - This saves the weather layer being displayed (fltcat, cip010, spd030, etc).
  • hemstuser# - This saves each of the user views (label, latitude, longitude, zoom).

For more customization, the URL parameters (see below) need to be used. They can be accessed through the "Permalink" available under the View menu.

URL Options

Here is a list of the URL options:

  • date=yyyymmddhhnn - This selects a specific date and time to display.
  • center=lat,lon - This will center the map at a specific latitude and longitude. The default is 39,-97.
  • zoom=level - This sets the zoom level. The default is 4. A higher number zooms in. A lower number zooms out.
  • basemap={terrain|light|dark|simple} - This selects the type of basemap. The default is light.
  • sat={on|off} - This turns the satellite layer on or off. The default is off.
  • satprod={ir|vis|wv} - Specifies the type of satellite image. The default is ir.
  • satopacity=# - Specifies the satellite image opacity (0=transparent to 1=opaque). The default is .5.
  • radar={on|off} - This turns the radar layer on or off. The
  • radopacity=# - Specifies the radar image opacity (0=transparent to 1=opaque). The default is .75.
  • wxtype=type - This sets the weather type. The default is fltcat.
    • none - no weather image displayed
    • fltcat - CVA flight category
    • ceil - CVA ceiling
    • vis - CVA visibility
    • icsev10, icsev20, etc - icing severity at 1000' AGL, 2000' AGL, etc
    • icprob10, icprob20, etc - icing probability at 1000' AGL, 2000' AGL, etc
    • temp10, temp20, etc - RAP temperature at 1000' AGL, 2000' AGL, etc
    • rh10, rh20, etc - RAP relative humidity at 1000' AGL, 2000' AGL, etc
    • wspd10, wspd20, etc - RAP wind speed at 1000' AGL, 2000' AGL, etc
  • metar={on|off} - This turns the METAR layer on or off. The default is off.
  • metplot=param - This selects the display parameter. The default is model. Multiple parameters can be selected separated by commas. Options are:
    • model - station model
    • temp - temperature
    • dew - dewpoint
    • rhum - relative humidity
    • alt - altimeter setting
    • vis - visibility
    • ceil - cloud ceiling
    • cover - cloud cover
    • wind - wind barb
    • wspd - wind speed
    • wgst - wind gust
    • cat - flight category
    • wx - weather symbol
  • metdensity={-1|0|+1|+2} - The METAR data density. The greater the number the more stations will plot. The default is 0.
  • metdecoded={on|off} - Specifies to show decoded data in popup dialog box. The default is off.
  • mettaf={on|off} - Specifies to add TAF to popup dialog box. The default is off.
  • metscale=## - Specifies scale factor for the METAR icon. The default is 1.
  • fltcat={on|off} - This turns the flight category layer on or off. The default is on.
  • fcdensity={-1|0|+1|+2|+3} - The FltCat data density. The greater the number the more stations will plot. The default is 2.
  • fcvfr={on|off} - Specifies whether to display VFR stations or not. The default is on.
  • pirep={on|off} - This turns the PIREP layers on or off. The default is on.
  • pirepi={on|off} - This turns the icing PIREP layer on or off. The default is on.
  • pirept={on|off} - This turns the turb PIREP layer on or off. The default is on.
  • pireptop=## - Specifies top level in hundreds of feet of PIREPs to display. The default is 125.
  • pirepbot=## - Specifies bottom level in hundreds of feet of PIREPs to display. The default is undef.
  • pirepage=## - Specifies age in hours of PIREPs to display. The default is 1.5 (90min).
  • pirepint=## - Specifies minimum intensity of PIREPs to display. Options are "all", "lgt" for light, "mod" for moderate and "sev" for severe. The default is all.
  • pirepscale=## - Specifies scale factor for the PIREP icon. The default is 1.
  • sigmet={on|off} - This turns the SIGMET layer on or off. The default is on.
  • sigtype=param - Specifies the types of SIGMETs to display. The default is all. The types are:
    • trop - tropical cyclone
    • conv - convective
    • turb - turbulence
    • ice - icing
    • ifr - IFR
    • va - volcanic ash
  • sigheight={on|off} - This turns the SIGMET height labels on or off. The default is off.
  • gairmet={on|off} - This turns the G-AIRMET layer on or off. The default is off.
  • gairtype=param - Specifies the types of G-AIRMETs to display. The default is all. The types are:
    • turb-hi - high level turbulence
    • turb-lo - low level turbulence
    • llws - low level wind shear
    • sfc-wind - high surface winds
    • icing - icing
    • fzlvl - freezing levels
    • ifr - IFR
    • mtn - mountain obscurations
  • hazard={on|off} - This turns the NWS hazards layer on or off. The default is off.
  • haztype={all|warn} - Specifies level of hazards. The default is all.
  • windbarb={on|off} - This turns the windbarb layer on or off. The default is off.
  • highways={on|off} - Turns highway layer on or off. These are primarily interstates. The default is off.
  • roads={on|off} - Turns roads layer on or off. These are primarily US and state highways plus some city streets. The default is off.
  • counties={on|off} - Turns county layer on or off. The default is off.
  • jetroutes={on|off} - Turns the top jetroutes layer on or off. The default is off.
  • firs={on|off} - Turns the ARTCC/FIR layer on or off. The default is off.
  • navaids={on|off} - Turns the Nav Airds layer on or off. The default is off.
  • airports={on|off} - Turns the airports layer on or off. The default is off.
  • runways={on|off} - Turns the runways layer on or off. The default is off.
  • tz=label,offset - Specifies the timezone to display. The label is a string to describe the time zone (e.g.EST) and the offset is the offset from UTC in hours (e.g.-5).
  • metric={on|off} - Specifies to display data in metric units. The default is off.
  • hover={on|off} - Turns on hover for features. The popups will come up when mouse hovers. Default is off.