May 27, 2023
Image of new map. Click to interact.
Briefly
The next generation of our interactive web map is slowly being rolled out. It is very similiar to the old google map. The layout is basically the same, some new layers have been added and some lightly used layers removed. Most notably, there is now an elevation chart that updates when panning. Currently, there are 84 distinct layers. I'm sure more will be added over time.
The biggest difference is what you don't see. Originally created in 2007 using Google Maps API it is now completely built with open source software, solely using HTML/CSS/JavaScript, cloud native data, your browser and that's it. For developers and those who think it's absurd to have AGOL sell your own data back to you, have a look under the hood.
The Details
Let's take a look at each of the map features.
The Information Pane
This is located at the top left, with the first line reading "Decimal Degrees". Let's look at each line:
- Decimal degrees: The latitude/longitude under the mouse cursor.
- Lat/lon at mouse click: The latitude/longitude where you single click the mouse.
- Bounding Box: When you pan or resize the map, this is the Lower Left/Upper Right coordinates of the map.
- GPS: Clicking on the "star" icon will fill this line with your latitude/longitude and distance from trail in miles.
- Bookmark: As you pan, zoom, add layers this bookmark link will update allowing you to save the map as customized. Right click link to save.
Icons
Settings/Layers: Select multiple layers to display on map.
Locate: Use device GPS to get your location.
Elevation: Show elevation chart for trail displayed in viewport.
Using Map Layers
The Postholer Interactive Map has always been noted for its hiking related layers. With 84 layers the new map is no different. Note, each layer group may have a 'No Layer' radio button. This will turn off the selected layer for that group.
Base Maps
While literally hundereds of base map layers are available, we keep that number to only a few unique base maps. All are publicly available, highly reliable base map tiles used widely across the GIS domain.
Points of Interest
These are layers directly related to terrain or specific to hiking, such as resupply. You can select more than one of these layers to display. Notable is the Meta/Mile Markers layer. This layer will display a 'mile marker' along the trail. Clicking on the mile marker will display further information, such as, elevation, today's weather (high/low temp, wind speed/gust/direction, 3 day rain/snow forecast)
Weather Forecast & Radar
Nothing is more important to a hiker than getting a weather forecast before they embark on their journey. The 'Point Forecast' layer allows you to do just that. Select this layer and click any where on the map. A window for that specific point will display a forecast from the National Weather Service.
NOHRSC Layers
These are layers specific to modeled SNODAS data. They allow you to see where and how much snow is sitting on the ground.
Fire Layers
Here you'll find current and historical fire layers as well as surface smoke. Very handy if you're sensitive to smoke or don't want to get chased off the trail by fire.
Climate
One of the most common questions hikers ask is, "How cold does it get?". The extensive set of climate data will answer that question. Annual precipitation, monthly min/mean/max monthly temps and monthly precipitation, too.
Protected Areas
These layers are handy for determining the land use type. If you're looking for a truly wilderness experience find a wilderness area that suits you. These layers have traditionally been popular with land managers and trail organizations.
Administrative
County, state and tribal boundaries for those who like to marvel at their fiefdoms consisting of strip malls, low density housing and casinos.
Terrain
Terrain layers are very handy for determining the type of terrain you'll be hiking in to. Of particular interest is the 'elevation step' which shows you elevation in 1000 foot colored increments.
Misc Layers
Catch all for non-specific and tenative layers.
Under the Hood
Other than storing our cloud native raster/vector data on a web server, no other back end services are used. This is the future for serving static data (updated hourly, daily, etc). The base maps are not hosted on postholer and we are not responsible for the care and feeding of these tile servers, which is ideal.
The performance and cost benefit of the above method cannot be understated. Some trail organizations use services such as ESRI's ArcGIS OnLine (AGOL). AGOL lets you upload your data and they serve it back to you and the public for a monthly fee. I am unable to convey the absurdity of this to you.
Enter cloud native data. In this case we are using Cloud Optimized Geotiff (COG) and FlatGeoBuf (FGB), which are raster and vector data respectively. All that is required to read/display this data is HTML/CSS/JavaScript from your web browser. This is as dumb and simple as it gets.
Specifically for raster data we use Daniel Dufour's fantastic GeoTIff JavaScript raster API's and FlatGeoBuf.org's vector API. It's all tied together with the long standing workhorse of web mapping, LeafLetJS.
For further details on working with cloud native data visit this simple tutorial and example.
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