What is GIS?

[Frickman]

In some threads here on the forum I've seen references to GIS. What does that stand for? I am quite familiar with GPS, but this is the only place I have seen GIS.

[happyj]

the acronym stands for Geographic Information System.

It can take gps data and coallate it with maps of all sorts. i.e sattelite, lidar, arial potographs...
So for example you could have a sattelite photo of a region and track firefighters on the ground from thier gps coordinates. Helps keep them out of trouble as well as position them appropriatly. I have data for my house and outbuilding that i interpose with GIS to have a view of what my lot will look like before i build.

[SwampDonkey]

GIS is Geographic Information System. It's been around for a long time, well since we've had decent computer operation systems, starting with UNIX. It's basically cartography, databases and drawing and editing tools in one package. It uses a computer program that has models of the earth programed into it to display graphical (images) representations of portions of the earth's surface. You can query such maps on address location or some other unique feature and your computer program zooms into that feature with the click of a button. Your maps can be stacked on layers or overlays (also called themes), so you can have several of these stacked to produce a map. One layer could be an aerial photo, another could be streams, one for roads, one for forest cover type boundaries, and one for property boundaries and you can continue building layers to represent each feature type you can conceive of. You can even take one of these layers, such as a stream layer and use a unique color or shading to subdivide it into categories (ie. intermittant, <1 m wide, 1-5 m wide....).

The more modern GPS handhelds (small computers) make use of GIS programs, and GPS data can be shown onscreen in real time as you collect it. You can also make edits to your GIS data in the field with the GPS handheld. When collecting with handheld GPS units the data is most always corrected with post processing software and basefiles downloaded from stations throughout the world to increase positional accuracy.

The most popular GIS program is from ESRI, called Arcview (ArcGIS).

http://www.esri.com    for more info.

[Frickman]

Wow that's amazing. Thanks for the answers

[SwampDonkey]

Some of the neet features of GIS is to be able to plan what, where, when, and how much. For instance from forest survey info I have an up to date forest inventory of my land, what groupings or categories of trees (forest cover types) I have, how much area for each and the age, also where it sits on the ground and many other attributes I stored in a database. I can use GIS to plan my harvesting of certain blocks in different parts of my land, how much I want to harvest this year and into the future. Those blocks or entire stands that have been harvested can be GPS'ed and the map of the harvesting can be added to my GIS and used to help plan future silviculture activities by year, location etc. If I want a map of a area I'm going to thin I can print off a map showing the aerial view and the perimeter of the work area and off to the bush I go. The key is to keep updating the data in the GIS. Some forestry companies fly and digitize their own photos at least every other year. Most of the forest cover typing is done from these photos and a small portion of stands are chosen at random for ground truthing or are cruised before they are harvested. Also permanent sample plots are used to project forest development over time for chosen cover types. It would be impossible to measure every tree is a large forest or harvest block.

[Redonthehead]

In other parts of the internet world it stands for "Google Internet Search"  ie: "do a GIS on how to get rich in forestry"  ;D