January 21, 2004

Geo Services FAQ

What is Geo Services?

It's an evolving project, so I'll do my best to explain how it exists at the moment I'm writing this, and where I'm trying to take it in the future.

Essentially, Geo Services allow you to display waypoints on a map. In the case of Geo Paddle, this translates into an easy way to view an area you plan to paddle with aerial photography or topo maps from the USGS. You can drill down (up to .25km for aerial photos, or .61km for topo maps), to see the area before you go! Identify those channels that wind through a marsh, or get a feel for the land before you go paddling. A future feature will allow you to download area waypoints for your GPS. In the case of Geo Tide Finder, the Geo Service allows you to see where tide and current stations are located in the Chesapeake Bay area and go directly to that station by clicking on it.

I get a Shockwave script error when I try to view some maps.

The bad news. Geo Services can be memory hungry. If you have less than 64 MB of memory in your computer, you may find it difficult to run the shockwave plug-in on maps which contain a lot of waypoints. If you have an area you are really interested in, email me and I will try and create smaller area maps with less waypoints for you.

How did you collect all those waypoints?

The majority were downloaded straight from the USGS. About 1.7 million waypoints are available to me to create Geo Services tools. After filtering out those of no interest to kayakers (such as buildings), over 570,000 waypoints covering the U.S. were made available to the Geo Paddle application. In the case of Geo Tide Finder, I imported approximately 7,000 tide stations used by XTide tide prediction software .

Some waypoints - and a large number of waypoints that hold special interest to kayakers such as launch locations, were contributed by visitors such as yourself. If you would like to see a waypoint added, you can send me the coordinates in DD.ddddd (Degrees decimal) format with a very brief description and I'll add it to the database next time I do a manual update.

How did you get those waypoints to display on the map?

Geo Service tools are based on WorldKit, a Shockwave plug-in written by Mikel Maron. Written to read waypoints in the form of RSS files, Mikel has graciously made some updates for me to add specific functionality to Geo Paddle.

Are there any hidden gems you aren't telling us about?

There are a few gems hidden in the thousands of waypoints, such as a link to a live video cam feed on at the Nanjemoy Creek Environmental Center or some photos from Tangier Island. There may be more - you'll just have to find them!

Why is some of the imagery so old?

The table below shows the percentage of photographs taken for each year, from 1988 to 1998, as of November 2000.

TerraServer's images are provided by the U.S. Geological Survey's National Aerial Photography Program (NAPP). This program is responsible for photographing the entire United States, with the goal of having complete coverage in 2001.

Obviously, the photos need to be taken in good weather conditions...the terrain must be clear of clouds. And there are a limited number of aircraft available to take the photos. Because of these issues and financial constraints, the program must be planned over multiple years, with plenty of time to allow for unforeseen problems.

The Geo services don't seem to work for me. How do I fix it?

The Geo services require shockwave 6+, a reasonable amount of base memory, and to be allowed to open new windows on your computer. If you think you have the first two items, make sure you don't have any popup blocking software running.

What's next?

Like all developmental projects, this is likely to change from what I have written here as I learn more about worldkit, php, mysql and other tools.

In addition, there are a few features (like waypoint downloads for GPS users) and a Geo Cache project for kayakers coming in the near future.

The Geo Stuff is cool, but it doesn't cover my area!

I've recently loaded about 1.7 million waypoints from the USGS that covers the US and it's territories. Of these, about 570,000 are water 'related'. If your not-for-profit club would like me to set up a Geo Paddle or Geo Tide Finder location for them, you can contact me at the email address on the side panel for details.

Woody