Talk:Geographic information system

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edit·history·watch·refresh Stock post message.svg To-do list for Geographic information system:
  • Remove Climate Change subsection from the Developments in GIS section. It is an example of a use of GIS technology, not a development in the technology.
  • Reference a good paper discussing the object/field abstraction in the Data representation section.
  • Combine the Projections, coordinate systems and registration section with the Relating information from different sources section.
  • history section - Tighten up discussion of CGIS (create a separate page for it?)
  • history section - Add discussion of DIME format (first well known use of topologic data structure)
  • history section - Add discussion of the US universities (Harvard Laboratory for Computer Graphics) that contributed to early GIS research (they went on to form ESRI and GRASS)

[ smervin 3/07 added sentence about Harvard Lab (LCGSA) to the History section. Also started separate wiki page about LCGSA but got 'speedily deleted' by zealous Wiki Admin who claimed "no assertion of notability"]

  • history section - Add contributions of SFU to early GIS research (TIN format)
  • Decide what to do about the GIS software section
  • Decide on an overall focus for this article and how it relates to other fields used by GIS (GI Science, geoimformatics, etc)
  • Needs to be information regarding the creation of data, specifically the different interpolation methods
  • Make this page plain language that wider community can understand
  • Raster section - this is very weak in its description of raster data.
  • Desperately needs a discussion of uncertainty in data measurement and analysis. This is probably the top item of importance and least intuitive for a newcomer to understand.
  • Review the use of data as a plural noun in this article. Though I acknowledge the traditional use of it as the plural of the Latin datum--and am not quick to abandon tradition--I find it awkward and distracting here. I believe the majority of modern English users treat data as a noun of quantity these days (like water, air, information)--see the usage note in its AHD entry here.-Eric talk 15:42, 8 September 2008 (UTC)

Article focus discussion[edit]

Till the second week of April 2013, there used to be a separate Wikipedia page for "Geographic Information Science (GIScience)". I had used the link for another Wikipedia entry. Somehow, any internal Wikipedia link to that entry now reverts to the page on Geographic Information System (GIS). I cannot find out who made that decision, but it is clearly uninformed and absolutely in error. GIScience and GIS are not the same thing. The page on GIScience needs to be reinstated. Lomdii (talk) 12:13, 28 April 2013 (UTC)lomdii,

This article appears to use quite a bit of text copied directly from a USGS page. It should be cleaned up with proper attribution.--Talkswithnumbers 22:40, 23 October 2006 (UTC)

There is an article called "Geostatistics", if any of you have the interest, please help to edit this page with the goal to inform and educate. Bohunk

I cleaned up the "Geostatistics section so it's not a list. If someone could review for accuracy, that would be great. --RWilliamKing 15:46, 6 April 2007 (UTC)

I veiw GIS as a field that encompases many disciplines such as cartography, statistics, databases, math... As I work, I will try to make links to these other related fields. – Rschulz

I think this page is already too long and broad. For example spatial analysis should have its own page but may be under the title "geographic information science". We should also use the pages geoinformatics and geocomputation to introduce some order. --

GIS is a very broad field and therefore any discussion can only be superficial. I agree we should be linking more to other pages (ie a quick discussion of routing here should link to the related computer science and topology pages; spatial analysis can link to spatial statistics). I do not know if a separate GI Science page is needed, since it is hard to separate from GI System. I have the same issue with geoinformatics and geocomputaiton. Perhaps we can say GIS makes use of methods from geocomputaiton (providing geocomputation can be properly defined). – Rschulz

Right now I am leaning towards leaving the system definition and mentioning the science definition. I also want to include that most uses of GIS only use a subset of all the available methods (ie online mapping only use routing methods). – Rschulz

I think there should be a seperate link to interpolation; perhaps interpolation should be discussed under a math-related heading, somewhere so that this topic may be explored in detail. – Bohunk

I believe the introduction is too complex and uses too many words to describe geographical information systems. It may be simpler to say :-

Geographical Information Systems refer to Databases of information which are interacted with through geographically accurate models (or representations) of the real world information they represent.

Possibly an example of this should be included. i.e. A building in a GIS would be proportional to it's real world counterpart and the address of the building would be represented in the data included in the database entry for the building. A building represented adjacent to this building in the GIS would be physically adjacent in the physical world the GIS models (or represents) Please feel free to edit as appropriate , I'm seeking here for a more concise and understandable introduction. The detail in the current introduction should be kept , but moved further into the entry in my opinion Wallacebiy 23:30, 30 April 2007 (UTC)


I still think the opening description is too long and uses overly pedantic description of exact parts of Geographical Information Systems. Essentially the three words describe it and an elucidation of those three words should open the article not the current overbearing paragraph long sentence ( sorry ) Wallacebiy 16:32, 17 September 2007 (UTC)

My opinion?

Cohen's process definition is superior (and should be cited alongside the ubiquitous component definition, whose citation I stuck into the article): "GIS is best defined as a decision support system involving the integration of spatially referenced data in a problem solving environment." for reference tag: Cowen 1988 "GIS VERSUS CAD VERSUS DBMS: WHAT ARE THE DIFFERENCES ?" PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING Vol. 54, No.11, November 1988, pp. 1551-1555. http://funk.on.br/esantos/doutorado/GEO/igce/DBMS.pdf last retrieved 9/17/2010. Hope I'm not stepping on toes here; your rebuttals/changes are welcome.Paulsuckow (talk) 16:12, 17 September 2010 (UTC)


This section: Relating information from different sources is a mess. A lot of the wording is awkward and makes no sense. The last sentence trails off. 76.247.12.93 (talk) —Preceding undated comment added 04:58, 15 September 2009 (UTC).


I agreed, and did something about it. See what you guys think; i believe it comes closer to helping grandma understand what GIS is all about. The intent of "Relating information from different sources" was originally data manipulation issues within GIS, but I think my more global treatment is an improvement. Whole books have been written (and taught from) about GIS data transformation and manipulation, and perhaps a separate article about this issue is warranted.Paulsuckow (talk) 16:24, 17 September 2010 (UTC)


I went through the first seven sections for read ease, and cleaned it up a bit. I added some sense links and descriptors left out of the thought development. I added applications which were obvious, yet missing. There is no way to remove thought development here from jargon and technology terms, so the flow of ideas and logic was addressed. July 2010 (J.H,) --Mountainway, Boulder, Colorado

GIS software discussion[edit]

The article consistently confuses GIS software with the geographic information system, that is, the data model and the decision processes it supports. Software plays a role, but it should be de-emphasied in favor of process. I may not get a chance to fix this and it wouldn't hurt my feelings if someone else tried. – Casu Marzu

Software is integral to the GIS system though and is the main conduit through which data is organized and displayed. I don't think you can separate the two. --Omnicog 15:03, 30 August 2006 (UTC)

Software is an important part of the traditional system definition, but a complete overview of available GIS software will be too long for this entry. Perhaps we can move the software section to its own page as was done for the Raster graphics / Graphics Programs split. We could also create a separate page for GIS data file formats. – Rschulz

I am thinking about doing the split I proposed, but leaving a GIS software section in this entry, which discusses the different types of software at a high level. This would mention categories such as spatial databases, client desktop gis software and web-based systems: it would not specifically mention any vendors which can be done on the GIS software page. Any comments? – Rschulz

It would do well to fix this, as most scientists and academics using GIS often conflate the software and process themselves such that they don't even understand the difference between GIS and, say ArcGIS. Also, that opening sentence is awful: "A geographic information system or geographical information system (GIS) is a system for creating and managing spatial data and associated attributes." It's tautological and lacking in any real explanation of what GIS is. It should be a one-sentence summation of GIS that, to paraphrase Einstein, explains GIS to your grandmother. Elijahmeeks 20:38, 19 March 2006 (UTC)

Geographic Information Science[edit]

The current GIS article seems too long, and it has (as been noted above) conflates the model and software used to implement it. Why not follow the International Journal of Geographic Information Systems move to Geographic Information Science?

One article could then concentrate on the software side (systems) and the other on the data structures and overarching methodology (science).

What do people think? --stochata 10:14, 24 July 2005 (UTC)

A few months ago I would have said any split would be bad, since I have not found a clear break between system and science. However, a break would allow the System entry to be expanded to include many different types of systems (web based, spatial databases, CAD, desktop, etc) and can include a discussion of other fields that make use of GISystems for their research.
Some helpful papers I found (via a quick google scholar search) are:
* MF Goodchild, 1992, Geographical Information Science
* DM Mark, 2003, Geographic information science: Defining the field
Before starting a new GIScience entry I would suggest putting up an outline here that details which topics will be moved to the Science entry and which should stay in this System definition. The outline can then be left for a while to allow people to comment on it. – Rschulz 18:15, 6 August 2005 (UTC)

'Support breaking into Systems and Science pages. This article is too long and breaking it into Geographic Information Systems and Geographic Information Science would make two more valuable articles. How about we develop the outline for the Science page on the discussion section of the current Geographic Information Science page? http://en.wikipedia.org/wiki/Talk:Geographic_information_science --Ray 11:21, 22 March 2006 (UTC)

'Support breaking into Systems and Science pages. Also suggesting consideration as to further split those into separate History of... articles. Willing to contribute to "History of Geographic Information Systems" article and/or corresponding section in the main article. Juhoeemeli (talk) 19:58, 13 July 2010 (UTC)

To me, it's very wrong to confuse geographic infomation systems with geographic information science. The former is an information systems that handle geospatial data, the latter is a scientific domain underlying or based on geographical infomation, with or without GIS. In other words, it is possible for one to conduct GISci without GIS.

stub?[edit]

Why is this article marked as a stub? – Mikeblas 16:31, 22 January 2006 (UTC)

It is not as of March 22, 2006. I see a section is marked as a sectional stub but that's it. --Ray 11:18, 22 March 2006 (UTC)

From a total outsider (me) who is trying to do research into the computer software side of the field this article is confusing. Its unclear from the article whether there are accepted data standards or where you can go to get more information on those standards.Nickjost 16:18, 15 August 2006 (UTC)

I agree, however the GIS field is so broad that it is difficult to create a concise article regarding the topic. I would suggest you explore the Object-relational database, the ESRI website, the vector and raster data model, geostatistics or spatial statistics, topology or geospatial topology, and the open-geospatial consortium (OGC) website. If you need any direction, or are having trouble finding information feel free to ask, I know lots on this subject.SCmurky 16:33, 15 August 2006 (UTC)

Use of GIS in archaeology[edit]

Could someone look at article GIS in archaeology to see if material can be merged into this article. FloNight talk 20:17, 15 February 2006 (UTC)

Oppose merge of GIS in Archaelogy into this article. The GIS article is alread far too long. I suggest Wikifing the Archaelogy article. I am about to pull section of the GIS article out into it's own article. --Ray 10:52, 22 March 2006 (UTC)

University Degree Programs[edit]

Would anyone oppose pulling out the University Degree Programs out into a new article? The Geographic information system article is already too long and the University Degree Programs is a really just a list that has the potential to grow immensely. --Ray 10:57, 22 March 2006 (UTC)


I pulled out the degree and certificate portion of this article and was working on it when a group of Wikipedia admins attacked. They were partially correct that such a long list of link does not belong on Wikipedia, however, they did not give me time to clean up the aritcle and just deleted all the info. It is no gone eveywhere except in the history of the GIS article. --Ray 00:33, 24 March 2006 (UTC)

Side note on why the list of links should have never been here

Coyprightability?[edit]

Can raw GIS data be copyrighted? If so, how about maps (including vector graphics) created from said data? (I'm talking here about copyright held by the sources, not by the mapmaker that uses the data to create a map.) --SPUI (T - C - RFC) 01:05, 7 April 2006 (UTC)

Raw? from what source? If the raw data is from the U.S. Federal Government (e.g. USGS, US Census Bureau,...), then it's in the public domain. State and local governments, as well as foreign governments, for the most part hold copyright to their data, as do of course private companies such as ESRI, Tele Atlas, and NAVTEQ. For maps created from copyrighted sources, if it's a derived work, combining sources in a new way, and other creative derivations, then I think it might be okay (but please cite the sources). In such cases, I prefer to upload the map in raster format. There was some debate about a map used on Jordanhill railway station, where it seemed to be "copied" or "traced" from Google Maps, but enough added creative input to it that think the map survived the debate. -Aude (talk | contribs) 01:34, 7 April 2006 (UTC)
Is such data creative though? Creativity is necessary for copyrightability - see Feist v. Rural. Have there been any cases related to GIS data? Any common views? --SPUI (T - C - RFC) 02:14, 7 April 2006 (UTC)
I think GIS data is copyrighted. Vector data is usually compiled from aerial photographs. Many creative decisions are involved deciding what level of detail to include in the vector data, how to setup the associated data attributes, classify things, etc. And with maps, some companies have been known to include artificial road segments or other artifacts that serve as watermarks for the map/data. But if you take the data, manipulate it, combine it with different sources, and express it in a new creative way, then I think it's okay (fitting with "If Feist were to take the directory and rearrange them it would destroy the copyright owned in the data.", from the case you cite). You just can't copy the particular creative expression, but simply the facts. What are the specifics in your situation? While I don't provide any legal opinions, maybe I can advise better. -Aude (talk | contribs) 02:29, 7 April 2006 (UTC)
See COUNTY OF SUFFOLK vs. Experian, and list of other court cases. -Aude (talk | contribs) 02:45, 7 April 2006 (UTC)
I don't have a specific situation - I think something about this should be added to the article. --SPUI (T - C - RFC) 03:04, 7 April 2006 (UTC)
In general, the article needs an overall good copyedit, but this would be a good topic to cover. When it comes to maps for Wikipedia, I mainly stick to maps of the U.S. and federal government data, though the National Geospatial-Intelligence Agency has some (not necessarily great detail) data for elsewhere. Sometimes, I'm willing to incorporate some state/local government data (provided, sources are cited, I do enough added-value creative manipulation and combine it with other sources, and upload it here as raster - no SVG). The arguments local governments use for copyrights are that they want to control redistribution of the data, to ensure it's accuracy, reliability, and integrity. Some local governments charge fees (sometimes hefty fees) to get the data. The arguments used by the Federal government (and others) for making GIS data public domain is that we already paid taxes for the creation of the data, and it's public information. In Britain, the EU, and other places, the laws are quite different, with those governments holding copyright. -Aude (talk | contribs) 03:15, 7 April 2006 (UTC)
It appears local government data is becomming more and more public domain, at least in California. San Diego and LA counties are now making their data freely available after the state attorny issued an opinion that such data should not be copyrighted.--Drewdowling 19:23, 19 April 2006 (UTC)
Shame on me, but I got most of the way through OMB_Circular_A-16 before I just got tired of reading the HTML version on the Whitehouse.gov site. I don't think anyone has created an article for National Spatial Data Infrastructure or Federal Geographic Data Committee yet which manage a lot of the interoperability of these spatial systems. I think this is somewhat relevant! —The preceding unsigned comment was added by RWilliamKing (talkcontribs) 22:23, 23 February 2007 (UTC).

External Link cleanup[edit]

There are currently more than 50 links in the 'External Links' section. Most of these are no more useful than what a Google search might turn up. There appears to be a number of links to interactive map sites and GIS data sites. At least one link appears to be an aggregator site for news stories tagged "gis". Many of the links are poorly described (or not described at all) and several are out of alphabetical order. The section is entirely too cluttered to be of much use to anybody.

GIS is a broad topic, and it certainly could benefit from a number of links to outside references, but many, if not most, of the current links should either be deleted or spun off into a separate article, such as the Geographic data article.

Please look through the links and delete any that are not essential to the article. If there are any disputed deletions, discuss them here.

Justin 02:24, 5 September 2006 (UTC)


Update - I deleted approximately 30 external links. Most of these were to commercial sites with data or services for sale, sites of limited regional interest, news aggregator sites which were choked with ads, job posting sites, newsgroups and wikis with very little traffic, free geocoding sites, air photo sites, and online mapping sites.
If I deleted anything inappropriately, please discuss it here. I suspect I didn't take out enough, so review what's left and delete what shouldn't be there. This should not become a directory of any and all sites related to maps and GIS everywhere around the world.
Justin 03:49, 5 September 2006 (UTC)

incorrect capitalisation[edit]

The article started out correctly with "A Geographic Information System" but went on to incorrectly capitalise it (and Geographic Information Science), although the indefinite article clearly shows that this should not be capitalised. This is not like Global Positioning System or the Internet, where i'm all in favor of capitalisation because they are proper nouns. --Espoo 12:49, 9 October 2006 (UTC)

There's a typo in "Data Creation

Modern GIS technologies rn digital information..."

    Also, this sentence does not make much sense: "GIS can be used by a company to site a new business location to take advantage of GIS data identified trends to respond to a previously under-served market. Most city and transportation systems planning offices have GIS sections; and..." Perhaps we can clean this up.  — Preceding unsigned comment added by 205.133.162.218 (talk) 13:33, 16 November 2011 (UTC) 

Government Uses[edit]

I have a tip that Northrop Grumman, while not an agency, is using GIS for something. I just thought it would be useful for the citation needed in "Relating information from different sources" if someone wants to look into it and narrow it down to an actual webpage.

By the way that section seems kind of random for "Techniques used in GIS". To me "Relating information from different sources" equates to miscellaneous, and that’s what the content seems to be. The word Relating seems to be an operating word, but it hasn't been operated.

== POV in THE GEODATABASE I thought someone would have noticed this by now, so maybe I am incorrect. I hesitate to say anything at all because of my obvious connection to the subject. However, the addition made by Ryangis reads to me like marketing copy. Expressions such as "Now more than ever before" and "like never before" do not sound very encyclopedic. Also, other systems have had the functionality for years to "set the transparency in the [raster] file properties to a desired percentage." Anyone else notice this? -AndrewDressel 23:02, 8 January 2007 (UTC)

Much better now, thanks to Mjrmtg. -AndrewDressel 16:40, 9 January 2007 (UTC)
There is an existing geodatabase article that treats the subject in a more general manner. I replaced the existing content (which only dealt with ESRI's implementation) with a link to the main article. Rschulz 18:25, 18 February 2007 (UTC)

Raster Section[edit]

This section really needs some work. It's very messy, vague and incomplete. —Preceding unsigned comment added by 75.51.70.232 (talk) 14:26, 19 September 2007 (UTC)

Intro section - confusing use of term "geomatics"[edit]

I have an issue with this statement:

A geographic information system (GIS) (also known as geographical information system, particularly in the UK, and geomatics in Canada) is a system for...

I understand how "geographical information system" and "geographic information system" or "geographic information systems" can be interchangeably applied, however "geomatics" is not similar to an "information system" - it is a term that encompasses a far broader study relating to geographically-referenced information.... it is more comparable with the term "Geographic Information Science". See a definition for geomatics here:

But what about "geomatics"?

This is a term that has been adopted by governments and private industry across Canada and which is becoming accepted worldwide. It encompasses the art, science, and technology involved in collecting and managing geographically-referenced information. This information can come from a variety of sources: earth orbiting satellites (e.g., the Global Positioning System; RadarSat), air and sea-borne sensors, and ground based instrumentation. Geographical information, manipulated with high tech computer hardware and software, plays an important role in activities such as environmental studies; management of land and marine resources; monitoring of dams, oil fields, and mines for subsidence or movement; navigation of ships and aircraft; oceanography; real estate transactions; and tourism. UNB - Dept. of Geodesy and Geomatics Engineering

I propose removing the geomatics reference from the introduction section of this article, or rewording it somehow, since I believe it is misleading for the reasons stated above.Plasma east 14:30, 22 October 2007 (UTC)

Requested Multi-Page Move to Single New Article[edit]

It is noted that there are at least four articles linked into this GIS 'See also' section:

which each deal with different, specific 'kinds of' applications to which GIS software can and has been put in the world .. and each are in need of some care and attention to be upgraded into Wikipedia standards..

Under the circumstances and given the nature of the articles in question .. it would seem appropriate to move them all and pull them all together into a single, new article entitled GIS applications —Preceding unsigned comment added by Bruceanthro (talkcontribs)

  • Combining all four of these into a single article would be quite long. What you want could be done much more simply by writing a summary of all four under GIS applications (which does not now exist), with links using the template {{See also}} or {{main}}. This will not lose information, and does not require admin intervention. Septentrionalis PMAnderson 16:17, 12 March 2008 (UTC)
Thanks for your otherwise sensible suggestion - I note that I started by trying to bring the four articles up closer to Wiki standard .. but found a lot of work was still required for them to be transformed into good, comprehensive Wikipedia quality, stand-alone articles. At present, combined, they will make a single, good sized, more wholistic and informative, start class, stand-alonne article - unless or until the originals are able to be more fully upgraded and expanded?!! Bruceanthro (talk) 16:33, 12 March 2008 (UTC)
Do write the combination. At that point, suggestions to merge the four articles into the new one will be dealing with a visible proposal, not something in your mind's eye, and will receive more intelligent consideration. Septentrionalis PMAnderson 18:17, 12 March 2008 (UTC)
OK .. while I am neither a specialist in this feild nor very knowledgable about the subject .. I have initiated GIS applications article .. as suggested. You'll note it is no longer red-linked! Will this do for starters? Bruceanthro (talk) 01:26, 13 March 2008 (UTC)

Uncertainty in GIS[edit]

One of the most important issues in contemporary GIS is uncertainty, both in data acquisition and analysis. Uncertainty is little understood by the novice, and even experts have a difficult time when confronted with multiple datasets of disparate sources and types that are used as the basis for analysis. Without a proper grasp of uncertainty, it is very probable--even certain--that GIS users and developers will unwittingly make egregiously unscientific claims. Basic problems like the ecological fallacy and the Modifiable Areal Unit Problem (MAUP) need to be mentioned. Ambiguity, vagueness, spatial error, classification error, boundary errors, etc. should be concisely described. A link should be provided to http://www.spatial-accuracy.org/ and other websites raising awareness for uncerainty. Without a discussion of uncertainty, many core issues faced by the GIS community are invisible to readers of this article. (Reference book Geographic Information Systems and Science chapter 6.)Lulolean (talk) 19:57, 14 May 2008 (UTC) The GIS accuracy depends upon source data. Land Surveyors have been able to provide high level of positional accuracy utilizing the GPS derived positions, www.fgdc.fgdc.gov/standards/documents/standards/accuracy/chapter3.pdf.) the high-resolution digital terrain and aerial imagery, https://njgin.state.nj.us/NJ_NJGINExplorer/IW.jsp) the powerful computers, Web technology, are changing the quality, utility, and expectations of GIS to serve society on a grand scale, but nevertheless there are other source data that has an impact on the overall GIS accuracy like: paper maps that are not found to be very suitable to achieve the desired accuracy since the aging of maps affects their dimensional. Developing a Digital Topographic Data Base for a GIS the topographical maps are the main source of data. Aerial photography and satellite images are extra sources for collecting data. The scale of a map is a very important aspect since the information content depends mainly on the scale of the map. In order to digitize the map, the map has to be checked with the theoretical dimensions, than scanned into a raster format, than the raster data has to be given the theoretical dimension by rubber sheeting/warping. Uncertainty is a significant problem in GIS because spatial data tend to be used for purposes for which they were never intended. Some of the maps were made many decades ago and at that time the computer industry was not even in the perspective. Map accuracy is relatively an issue of minor importance in cartography. Maps use a very constrained technology of pen and paper to communicate a view of the world to their users. Cartographers feel little need to communicate information on accuracy, but when the same map is digitized and input into a GIS, the mode of use changes. The new uses extend well beyond the domain for which the original map was intended and designed. A quantitative analysis of maps brings accuracy issues into focus. The equipment used to make measurements in GIS is far more precise than the machines of conventional map analysis. The GIS accuracy depends upon source data. Land Surveyors have been able to provide high level of positional accuracy utilizing the GPS derived positions, www.fgdc.fgdc.gov/standards/documents/standards/accuracy/chapter3.pdf.) the high-resolution digital terrain and aerial imagery, https://njgin.state.nj.us/NJ_NJGINExplorer/IW.jsp) the powerful computers, Web technology, are changing the quality, utility, and expectations of GIS to serve society on a grand scale, but nevertheless there are other source data that has an impact on the overall GIS accuracy like: paper maps that are not found to be very suitable to achieve the desired accuracy since the aging of maps affects their dimensional. Developing a Digital Topographic Data Base for a GIS the topographical maps are the main source of data. Aerial photography and satellite images are extra sources for collecting data. The scale of a map is a very important aspect since the information content depends mainly on the scale of the map. In order to digitize the map, the map has to be checked with the theoretical dimensions, than scanned into a raster format, than the raster data has to be given the theoretical dimension by rubber sheeting/warping. Uncertainty is a significant problem in GIS because spatial data tend to be used for purposes for which they were never intended. Some of the maps were made many decades ago and at that time the computer industry was not even in the perspective. Map accuracy is relatively an issue of minor importance in cartography. Maps use a very constrained technology of pen and paper to communicate a view of the world to their users. Cartographers feel little need to communicate information on accuracy, but when the same map is digitized and input into a GIS, the mode of use changes. The new uses extend well beyond the domain for which the original map was intended and designed. quantitative analysis of maps brings accuracy issues into focus. The equipment used to make measurements in GIS is far more precise than the machines of conventional map analysis. http://nationalmap.gov/gio/standards. The truth is that all geographical data are inherently inaccurate, and these inaccuracies will propagate through GIS operations in ways that are difficult to predict.

Accuracy Standards for 1:24000 Scales Map

1:24,000 ± 40.00 feet

This means that when we see a point on a map, its "probable" location is within a +/- 40’ area. EKraemer-352P (talk) 16:37, 23 June 2010 (UTC)E.Kraemer

Image copyright problem with Image:GeaBiosOpenLaszloSatelliteMappingApplication2.PNG[edit]

The image Image:GeaBiosOpenLaszloSatelliteMappingApplication2.PNG is used in this article under a claim of fair use, but it does not have an adequate explanation for why it meets the requirements for such images when used here. In particular, for each page the image is used on, it must have an explanation linking to that page which explains why it needs to be used on that page. Please check

  • That there is a non-free use rationale on the image's description page for the use in this article.
  • That this article is linked to from the image description page.

This is an automated notice by FairuseBot. For assistance on the image use policy, see Wikipedia:Media copyright questions. --00:23, 13 September 2008 (UTC)

GIS Customisation[edit]

GIS customisation is the process of adding and/or modifying user interface and functionalities on an existing system to suit the requirements of a customer —Preceding unsigned comment added by Sajeevang (talkcontribs) 09:00, 31 October 2008 (UTC)

Move[edit]

The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

No consensus to move. Vegaswikian (talk) 21:45, 17 March 2010 (UTC)

Geographic information systemGIS — per WP:COMMONNAME and this discussion. Note that GIS redirects here. —Justin (koavf)TCM☯ 20:01, 9 March 2010 (UTC)

  • Comment didn't you just suggest that the categories be renamed the other way? 70.29.210.242 (talk) 05:16, 10 March 2010 (UTC)
  • Comment Yes I did; I linked it above. —Justin (koavf)TCM☯ 00:25, 14 March 2010 (UTC)
  • Oppose Acronyms should only be used when they are universally understood. Many people wouldn't have a clue what GIS stands for. It simply isn't common enough. Skinsmoke (talk) 17:39, 13 March 2010 (UTC)
The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Any expert in constructing isohyets available?[edit]

I need help,[edit]

I was directed to this page by User:Opbeith to have a request solved.Can anyone help me.

Can anyone get close to any climate organisation e.g NASA or others to get climate information on Nigeria containing average rainfall for all nigerian regions and use isohyets or contour lines to contruct the rainfall information of Nigeria for the Geography of Nigeria article and arrange them on the map in the format provided below.

 mm=Millimeters
     
0 mm   - 500mm
500mm  - 750mm
750mm  - 1000mm
1000mm - 1250mm
1250mm - 1500mm
1500mm - 1850mm
1850mm - 2000mm
2000mm - 2500mm
2500mm - 3000mm
3000mm - 3500mm
3500mm - 4000mm
above 4000mm.
thanks Netknowle message me!  03:58, 15 June 2011 (UTC)

Section "Slope and Aspect"[edit]

Please define 'aspect' in this context Peter (Southwood) (talk): 08:35, 30 June 2011 (UTC)

I added definitions for slope and aspect, and linked formulas to context of definition, and a bit of cleaning up "Slope and Aspect" User:Vrkunkel. Sorry i took a while to update this (>1 year!). —Preceding undated comment added 01:21, 12 July 2012 (UTC)

Advantages of a GIS program over Google Maps/GIMP combo[edit]

Shouldn't we mention the advantages of a GIS program over Google Maps (or GPScoordinates/GIMP combo (the latter can capture maps -using printscreen- and edit them too (some google maps as http://flood.firetree.net/ even allow simple elevation info); some advantages I found

  • GIS software may be connected to a online database with very detailed maps (level of zoom and elevation info/3D view; the latter also provides options for flood protection purposes)
  • GIS can use satellite maps and road maps
  • possibility to export/import specific map sections (4 GPS locations can be entered after which the program crops the map to the specified range) ?
  • more options (distance calculation, ...)

In regards to the first (online database with very detailed maps); is GDAL/OGR such a database ? Or is it just a file conversion tool ? See http://grasswiki.osgeo.org/wiki/Importing_data

Other questions: Can openstreetmaps maps be easily printscreen/pasted and/or are there export capabilities in some programs. I'm thinking of programs like navit, Rana, FoxtrotGPS, Trekbuddy, NaviPOWM, mumpot. Perhaps gvSIG mini may also be an option, although it's an Android app (not Linux/Windows program) ? See also Comparison_of_free_off-line_GPS_software

Does a mere printscreen/paste from Google Earth or Marble to a GIS allow to capture the elevation info (I suspect not). Is there an export function for this ? Can a specific map section be entered ?

109.130.201.33 (talk) 07:41, 13 May 2014 (UTC)

Small update; copy/pasting doesn't seem to work with one free GIS (gvSIG), yet openstreetmap data can be loaded though (online database available); see

http://blog.gvsig.org/2013/05/24/teselas-de-openstreetmap-sobre-gvsig/ http://www.youtube.com/watch?v=nUjN7SOwLQ4#action=share [1]

109.130.201.33 (talk) 10:58, 13 May 2014 (UTC)

  1. ^ WinXP users need v2218 for OSM support