GIS Modeling in Raster

June 8, 2009 by Timothy
Filed under GIS Books

I just finished up a class using the book: GIS Modeling in Raster by Michael N. DeMers. At first I was a bit overwhelm with the content of the book, but it all soon fell into place. This book has been out for several years now, but it is one of the best available on the subject of rasters (some see this as both a positive and negative).

The book begins by covering the various features that can be represented with rasters. I found it interesting that the square grid is not the only type of grid, but triangle, parallelogram, and hexagon could also be used. Types of rasters discussed included the simple raster, extended raster, quadtrees, and cellular automata.

A key element to rasters is map algebra. This topic covers conceptualizing zero through two-dimensional space with grid cells and conceptualizing three-dimensional space with grid cells. The map algebra chapter provides a very good introduction to manipulations. A variety of operators and functions are covered. For a more detailed section on functional operations, chapter 4 covers trigonometric, exponential and logarithmic, reclassification, selection, and statistical.

Chapter 5, 6, and 7 covers the whole modeling gamut. Chapter 5 starts it off with how to think spatially. Identifying patters within the data is covered. Learning how to use tools such as landscape, literature survey, maps, aerial photography, and statistical techniques to identify these patterns. Within modeling essentials, types of GIS models are discussed. The models include those based on purpose, methodology, and logic. With the basics of modeling covered, the flow of the book moves into conceptualizing the model. This begins with defining your goals, adding the spatial dimension, and identifying data elements. With the model conceptualized, chapter 7 shows how to carry out your model.

The book is summed up with techniques for conflict resolution and prescriptive modeling along with verification, validation, and acceptability. The areas covered here include the orpheus land use allocation model, consensus building, hierarchical techniques, statistical techniques, and displaced fuzzy ideal. Additionally, there are sections on model correctness, parsimony, and model acceptance.

Overall, this is an excellent textbook and great reference source. Although I found it a little hard to read in some spots, I was able to benefit and apply many concepts to my daily work flow. Also note that there is downloadable data made available that corresponds to the chapter concepts.

Chapter 1: Introduction
Chapter 2: Nature of the Data
Chapter 3: Map Algebra
Chapter 4: Characterizing the Functional Operations
Chapter 5: Modeling Essentials
Chapter 6: Conceptualizing the Model
Chapter 7: Model Formulation, Flowcharting, and Implementation
Chapter 8: Conflict Resolution and Prescriptive Modeling
Chapter 9: Model Verification, Validation, and Acceptability

Check out this book for yourself: GIS Modeling in Raster

Tags: Cartography, Functions, GIS, map algebra, Mapping, Modeling, rasters

ASPRS Certification Program

March 3, 2009 by Timothy
Filed under Career

2 Comments

The American Society for Photogrammetry and Remote Sensing has a certification program in place that could provide ample support to boost your career forward. As of current, there are just a few certifications available for the GIS industry. The ASPRS, one of the longest standing programs, was started in 1975 with the Certified Photogrammetrist category and added two additional categories in 1991. In 1998, the program began requiring an examination to be taken in order receive one of the certifications. The ASPRS Board of Directors approved a Provisional Certification Program in 2006 to allow students certification eligibility since most do not meet the experience requirements of the program.

Here are the certification categories that ASPRS offers:

1. Certified Photogrammetrist
2. Certified Mapping Scientist, GIS/LIS
3. Certified Mapping Scientist, Remote Sensing
4. Certified Photogrammetric Technologist
5. Certified GIS/LIS Technologist
6. Certified Remote Sensing Technologist

Note that there are provisional certifications in all the above categories for graduating seniors in geospatial sciences. This is an advantage that educators should publicize to their student. Having even a provisional certification can give newly graduating students a boost to their career.

Application Process:

Complete application
Provide four references
Have successful peer review
Pass an exam in the chosen category

Here is a summary of the process for the professional certification [the first three categories] [it's similar for the Technologists as highlighted below]

The rules for certification are: six years total experience are required of which three are professional in nature. Application forms are filed with four references and are sent to a peer review group for evaluation.Those who pass peer review are eligible to take the four-hour multiple choice examination which is given, as needed, in a location in the US relatively close to where examinee lives. When required, overseas exams are arranged on a case-by-case basis. The Examination consists of questions a professional should be able to answer in areas such as earth sciences, surveying, physics, imaging systems, photogrammetry and GIS. There is no primer as with the Professional Engineer or Land Surveyor examination. Those not passing are allowed to retake the exam within six months of notification at no additional cost.

The application fee is $275 for ASPRS members and $400 for non-members.

Membership information is available at:
http://www.asprs.org/membership/

The Certification and Recertification Guidelines:
http://www.asprs.org/membership/certification/certification_guidelines.html

Application for Certified Photogrammetrist or Mapping Scientist:
http://www.asprs.org/membership/certification/certification_app.pdf

Reference form:
http://www.asprs.org/membership/certification/reference_form.pdf

Exam questions matrices by category:
http://www.asprs.org/membership/certification/certification_examination_matrix.html

In preparing for the certification exam, workshops are usually offered to help the applicants. These workshops usually take place during the ASPRS Annual conference. Check the website for more details. The workshops are described as follows:

The purpose of this workshop is to prepare individuals who are planning to sit for the ASPRS Certification exams. The workshop will begin by explaining the purpose and form of the exam. It will then identify key topical areas which an applicant should be aware of prior to taking the exam. The instructor will review the basic concepts and sample questions to show how these topics will be tested for on the exam. Finally, the workshop will identify resources which exam takers should be aware of and study from in their preparation for the examination.

Workshop Topics Include:

Purpose of the exam
Photogrammetry
Remote Sensing
Geographic Information Systems
Other topical areas of importance in preparation for the exam

Here are some suggested texts for examination review:

As noted in the list of available categories, there is a certification program for Photogrammetric Technologists, Remote Sensing Technologists, and GIS/LIS Technologists. These technologists areas only require three years of experience instead of six. Check the Guidelines for additional details.

If you would like more information, please visit www.asprs.org or request additional information from certification@asprs.org.

Thanks to Jesse Winch, Program Manager with ASPRS, for this valuable information.

Tags: ASPRS, Certification, GIS, GIS Certification, LIS, Mapping, Mapping Scientist, Photogrammetry, Professional Certification, Remote Sensing, Technologist

Easily Create a Custom Google Map

February 18, 2009 by Timothy
Filed under GIS Tips, Google Maps

2 Comments

Google maps are all around us. These maps can be embeded into websites. They can also be customized to include various types of information for display.

Instead of looking up temporary maps, you can create custom maps with various elements like pushpins, lines, and polygons that can be saved and accessed on demand. These maps can be accessed with a direct link or placed on a web page.

To create a custom map:
1. Go to Google Maps

Make sure you are logged into Google so that your map is saved under your account. If you do not have a Google account, you can create one here.

2. Click on My Maps