Friday, May 2, 2008

GIS for mining

The mining market is living a fantastic period and ESRI published a link with a connection between GIS and Mining. This link presents an overview about how we can use GIS for mining and cover the following steps: 1) exploration, 2) operations, 3) management and 4) environmental management.

Sunday, April 20, 2008

Using EPSG code in GDAL

EPSG is a code from the European Petroleum Survey Group that makes a numeric codes associated with coordinate system definitions. For example, EPSG:29193 is SAD69 / UTM zone 23S cartographic system. It's possible to browse all coordinate system definitions and codes in Spatial Reference web site.

The GDAL library in FWTools 2.1.0 allows the coordinate systems conversion from images using ESPG code.
These utilities allow the coordinate system (SRS = spatial reference system) to be assigned in a variety of formats.
  • EPSG:n: Coordinate systems (projected or geographic) can be selected based on their EPSG codes, for instance EPSG:27700 is the British National Grid. A list of EPSG coordinate systems can be found in the GDAL data files gcs.csv and pcs.csv.

In the example below is shown how to convert an image in:

GEOGCS["SAD69",DATUM["D_South_American_1969",SPHEROID
["GRS_1967_SAD69",6378160,298.25]],
PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]
To:
PROJCS["SAD69 / UTM zone 24S",GEOGCS["SAD69",DATUM["D_South_American_1969",SPHEROID
["GRS_1967_SAD69",6378160,298.25]],PRIMEM["Greenwich",0],UNIT
["Degree",0.017453292519943295]],PROJECTION
["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",-39],PARAMETER
["scale_factor",0.9996],PARAMETER["false_easting",500000],
PARAMETER["false_northing",10000000],UNIT["Meter",1]]
gdal_translate -s_srs ESPG:4618 -t_srs EPSG:29194 gcs_sad.tif utm_sad.tif.

Saturday, April 5, 2008

GDAL with BIGTIFF support

The GeoTIFF format represents the effort of more than 160 companies and organizations from remote sensing market, GIS, mapping and survey data, to establish a format for interchangeable georeferenced raster files on TIFF format. With this characterirstic, the GeoTIFF format inherits a limitation on the TIFF format on producing files greater than 4 Gigabytes.

To go around this limitation, there is a new format available that allows the creation of files greater than 1 terabytes. This format is called BigTIFF. This format has the sponsorship of companies such as WeoGeo, Safe, Leica and ESRI, and it can be observed in the press release of Frank Warmerdam wich was published in Slashgeo.
FrankW writes "As announced in this press release four industry sponsors (WeoGeo, Safe, Leica and ESRI) have gotten together to fund development of BigTIFF support in libtiff. This extension adds support for GeoTIFF files much larger than 4GB! With libtiff used by most open source and commercial applications there is reason to hope that BigTIFF support will be widespread in our industry within the next year or two (sooner for open source!)." BigTIFF was previously discussed.
I can not precise when it happened but I know that the version of the library GDAL/OGR 1.4.4 of November of 2007, has already introduced the BigTIFF format support for the generation of GeoTIFF images. For those who want to work with the FWTools tool in the version 2.0.2, the BigTIFF format support through the library GDAL / OGR is already available.

The hypothetical example below shows the conversion of an image in ERDAS image format (. img), wich is greater than 4 Gigabytes, to GeoTIFF format using the FWTools shell.
gdal_translate -of GTiff -co "TFW=YES" -co "BIGTIFF=YES" "c:/temp/image.img" "c:/temp/bigtiff.tif"
The command -of defines that the output format is GeoTIFF, the command -co "TFW=YES" force the creation of a ESRI world file (.tfw) to the image generated, and, the command -co "BIGTIFF=YES" allows the generation of a TIFF file greater than 4 Gigabytes.

Wednesday, March 19, 2008

GIS Video

A very nice video about GIS technology. It makes me remember why I love to work with GIS.


ArcGIS Tutorial

A Portuguese and Spanish ArcGIS tutorial was developed by a geologist called Rodrigo Nobrega and is freely available on the web.

My first contact with Rodrigo was in the end of 1999 and beginning of 2000. In this period he was consultant of a project developed by the company Geoexplore and he also was the instructor of a course about digital images processing. In 2004 I met him again and he was already a doctoral student of FACOM (Faculty of Communication from the Federal University of Bahia), and was developing a project related to cyberculture and cybergeography.

During this period I had a contact with the ArcGIS tutorial developed by him. It is an excellent quality material for beginners and even for someone who has already a good experience. Some animations in flash are available and are well didactic, such as the sequence of animations that shows us how to use the georeferencing tool with pictures on ArcGIS (1, 2, 3, 4, 5 and 6).

For our Spanish-speaking friends, a version of the tutorial in Spanish is available. This site is very interesting to visit!

Sunday, October 28, 2007

James Fee’s Interview

Today's post is the result of an interview with the creator of the sites Spatially Adjusted and Planet Geospatial. This interview counted with the support provided by the system analysts Glaucio Rocha and Marcos Miranda, which are part of the Technology Information Group (NTI) from the Water Resource Agency of Bahia State in Brazil.

ResenhaGIS:
James, hi from Brazil. First of all thanks a lot for the chance of this interview. What motivated James Fee to work with GIS and what was the motivation to create the Spatially Adjusted? Do you think that the Spatially Adjusted would become a reference to this new publication world ( “new media” like web, podcast and blog)?

James Fee: I started to get involved with GIS as I graduated from college. I have a BS in Geography and I was working on one of my final cartography projects and happen to see someone turn in a project that wasn't drawn with pen or ink (or even Illustrator or Freehand). I asked how he created such a map and was told it was this program called ArcInfo. I decided then I had to learn more about the program. I got an job at a local city here in Arizona working with ArcInfo and early versions of ArcView. After a while I started to get more involved with GIS development, first with AMLs and later with Visual Basic and .NET as ESRI moved into those markets.

As for the reasons for starting my blog it really comes out of trying to get a better understanding of open source GIS. I figured if I blogged about my issues, people would help (and they did). In the end our company didn't end up going the open source route and we decided to focus back on ESRI so I ended up blogging about ESRI. Honestly I had no idea that so many people would ever find my blog worth reading, but I'm happy to hear so many do. I think at the time I started this blog, most existing GIS portals and "blogs" were full of ads and press reports, not full of much that "ordinary" professional GIS people would really be interested in. I just blog about what interests me and what I think about the geospatial industry and that seems to interest people. My blog has been a blast and I'm glad to see some many more bloggers on Planet Geospatial. It used to be so hard to keep up on GIS news 2 years ago, but now every day my RSS aggregator is full of interesting news and commentary from other GIS professionals. Quite a change from the old print media days.

RG: What do you think motivated the company to abandon the open source route? Do you believe that the open source projects are trustworthy, you know, that they are ready to be used in a large project?

JF: We abandoned open source because our clients didn't want to shift from ESRI software. We thought they would because of reduced licensing costs, but they felt the "safer route" was to stay with ESRI. We never pushed this issue very much and continue to market open source where is makes sense, but our focus remains on ESRI and will probably continue to do so for years to come.

I think open source has proved itself over the past few years being able to handle large enterprise deployments, but of course that depends on the each project and how mature it is. I think eventually open source will make a dent into the professional GIS marketplace, but that will take time as people are educated and the tools become more mature. Many projects are already there and I think the new Open Source Geospatial Foundation will help others get more organized.

RG: We have two Brazilians guys participating in the foundation, they are very confident that open source geospatial “movement” or “industry” will gain projection with the foundation. I would like to know what is your impression about the OSGeo? How do you see ER Mapper as the primary sponsor on GDAL/OGR development and the Autodesk Map Guide Open Source?

JF: To be honest I haven't been following OSGeo as much as I probably should, but from what I've read and heard they have been doing a pretty good job of getting organized. I've been trying to follow the email list, but it has been hard given how busy I am. I kinda wish they would blog about it all rather than use the wiki, but its fine.

I've really got no opinion about either ER Mapper or Autodesk supporting open source. I think it makes a smart business decision to go open source some times and it appears at least in Autodesk's case it was a good idea as MapGuide had really fallen off the radar of many people.I think getting involved with OSGeo early on will make good business sense for those companies that have "signed" on and those who aren't involved yet will be left outside looking in as the whole open source GIS begins to gel. Interoperability is key for the future and closed platforms will slowly die off (proprietary or not).

RG: Many DBMS are starting to store geometry objects and these applications are growing on spatial functionalities. Nowadays it’s possible to develop a WEBGIS based on a spatial database structure. Do you believe that GIS platforms (Arcview, Mapinfo or Geomedia) like they are today are near to death?

JF: I think the general movement is toward server-based GIS. I don't think that desktop GIS will go away, but enterprise customers will probably migrate much of their geoprocessing to servers, allowing companies to spend much less money on full copies of ArcGIS (for example) on everyone's desk. A client such as Google Earth can display server data, the only missing link is a framework to program tasks within these clients that would connect to the servers. I think ArcGIS Explorer might be this client, but we aren't there yet.

Of course there will always be the small GIS shops that cannot afford the high cost of server GIS (given the small number of seats they have) so "stand alone" desktop GIS applications such as Geomedia or ArcGIS will always be around.

RG: I really believe it. On the route of Google Earth, Yahoo! Maps and Microsoft Virtual Earth, why ESRI is so slow on launching the ArcGIS Explorer? Is there still enough time for ArcGIS Explorer to compete with these applications? Are there other differences between ArcGIS Explorer and the “standard” Google Earth?

JF: Many people think ESRI is being slow about getting ArcGIS Explorer (AGX) out the door.I can't say anything about specific issues ESRI might be having (because I don't know), but I think the schedule has more to do with the ArcGIS 9.2 Beta release schedule than anything the AGX team might be doing. This brings us to the point why AGX is important given the huge install base of Google Earth (GE).

First, AGX is a similar application to GE as both are "globe applications", but that is where they begin to differ. First off while Google Earth is free for personal use, you must buy a pro version to use it with work. That makes it very hard for consultants like ourselves to deploy GE solutions to our customers (who might have GE on their computers, but only a personal license). AGX will be free for anyone to download and install (consumer or pro) so you don't have to worry about what license people have. GE includes some great imagery of the world and I don't think ESRI will even begin to try and compete on that level. ESRI announced at the Dev Summit that they would have 1m imagery for the USA available, but they didn't announce if any more countries will be available. So if you are into sightseeing, I'm sure GE will always trump AGX, but that is OK because of the next big difference. AGX can connect to ArcGIS Server, ArcIMS and WMS services so even if you are working in an area that doesn't have good coverage, you can set up your own web mapserver (even UMN Mapserver) to fill in the gaps. AGX will have complete support for KML/KMZ so you'll be able to use the huge selection of existing files. Another huge feature for AGX is the new task framework. ESRI has shown some demos on their main website showing how you can create tasks inside AGX (using .NET) that can perform GIS analysis on your data layers. What this means is if you have an ESRI backend server, you'll be able to take advantage of the capabilities of that server and allow users of AGX to perform their analysis right from inside AGX. The possibilities of this are endless and many more users will be able to take advantage of a professional GIS without having to pay for a full blown GIS system. Plus they'll be using a GUI that is similar to both GE and existing ArcGIS applications so it will all feel very familiar.

I guess if you look at AGX as a competitor to GE, then I guess I'd say it is too late for AGX to overtake Google. But, I don't think ESRI looks at AGX that way and isn't in the consumer marketplace that Google competes in. AGX is a tool that will take the globe application in a different direction from GE and hopefully to the benefit of GIS professionals.

RG: James, this is our last question and I am very happy with this interview and all your answers. It is my first interview and in my opinion you are doing a good job with Spatially Adjusted and Planet Geospatial. Keep up the good work! Could you give us one last opinion about the “future” of GIS Industry – what will it be like in the next four years?

JF: I think we'll see a movement back to "server-side GIS" and away from desktop GIS. No long is GIS confined to 1 or 2 people in a group. Everyone needs access to perform the same kinds of analysis that you used to need a GIS professional to accomplish. But at the same time the tools need to become simpler. I think we've seen this start with ArcView GIS 3.x, then ArcGIS and now Google Earth. Eventually we'll not even need a stand alone Google Earth type application, but just a web browser and a mouse.

Of course the world will still need GIS professionals to keep these systems up and running, develop datasets and develop the models needed to perform GIS analysis.

Saturday, October 27, 2007

Presentation

I am a user that works with geospatial technology. Since my college time I am devoted to read, study, test and work on projects related to geographical information technology.

I want to address here the most varied issues linked to geoprocessing and exchange ideas with professionals from this area or with people interested in talking about the subject.