Thomas LiuzzoRST Land Surveying

3720 North Robert Road Suite 2Prescott Valley, Arizona 86314

(928) 775-9890

Geographic Information SystemsGeographic Information Systems

A Surveyors PerspectiveA Surveyors Perspective

August 8, 2004 ESRI Survey & GIS SummitSlide 2

IntroductionIntroductionWhat does GIS stand for? I have heard the reference “Get

it Surveyed” from some, I like to refer to, “Get in Sync”. This past year, Arizona has experienced a step towards unification betweenits GIS professionals and its Land Survey Professionals. With increased awareness and voluntary education, the two communities are demonstrating joint growth that will provide more accurate and more detailed information to the public that we serve. As of July 31, 2004 the GIS community is officially part of the Arizona Professional Land Surveyors. APLS successfully adopted new bylaws including GIS professionals as part of our organization

The GIS Software Industry has been growing at a rate of more than 20% a year with total sales in excess of $800 million.Although the components are simple to purchase, the expertise toproperly allow these systems to function is often underestimatedand the proper data compilation is expensive and time consuming.Thus making planning critical.

August 8, 2004 ESRI Survey & GIS SummitSlide 3

What do a GIS and a What do a GIS and a Survey have in CommonSurvey have in Common

! Collect, store, and retrieve information based on it’s spatial location

! Identify locations within a targeted environment, which meet specific criteria

! Explore relationships among data sets

! Spatially analyze the data within each environment

! Display the selected environment numerically and graphically, before and after analysis.

Simply put, both are an information management system which can:

August 8, 2004 ESRI Survey & GIS SummitSlide 4

Building the FoundationAll of this data is georeferenced, that is, linked to a specific location on the surface of the Earth through a system of coordinates. One of the easiest to work with in terms of projection is Latitude, Longitude, and Height. A GIS or a survey are not isolated to objects and their position, Each can incorporate properties of these objects as additional data within the system. Choosing the control is Critical.

August 8, 2004 ESRI Survey & GIS SummitSlide 5

Coordinate SystemsCoordinate Systems

Determining if your GIS or Survey will be ground based or grid based is a very important decision. When either are created, some imagination is required as to the coverage of the maximum area and the overall purpose. We need to look into a crystal ball and try to anticipate any and all uses of the end product. ! Choose Grid or Ground Based System.! Select stable balanced geodetic control for basis of projections! If the system is ground based choose a centroid for the projection.! State selections for Coordinate system in metadata.

August 8, 2004 ESRI Survey & GIS SummitSlide 6

AccuracyThe question of accuracy has been the most storied between the surveyor and the GIS specialist. While surveyors are skilled in measurement techniques and reporters of rights upon the ground, the GIS has introduced the term “mapping grade” and “sub-meter”. There is little cost difference to establish a GIS in Survey Grade versus Mapping Grade. ! Determine level of accuracy the various layers require.! Shoot for the highest level regardless of cost.! Clear Statement of how the data is acquired.! Test Data to prove statements of Accuracy.! State selections for accuracy requirements in metadata.

August 8, 2004 ESRI Survey & GIS SummitSlide 7

Data ManagementOne of the overlooked variables in the data acquisition and datamanagement areas is the operators experience level. With GIS technology rapidly changing, a student of the curriculum will arrive at work ready to operate the software, but do they know what the data is?! Operating a GIS is more Technique than Theory.! A surveyor needs to convey to the operator what his data represents.! The operator needs to allow the surveyor a chance to proof the data.! Establish a data dictionary early in the life of the GIS.

August 8, 2004 ESRI Survey & GIS SummitSlide 8

RelationshipsA group of us were discussing GIS, and an older veteran surveyor made this statement, ”Unfortunately I feel that GIS is something that has passed us (meaning surveyors) by.” This is not the major consensus in the survey community. We need to utilize each others skills and work together. The Arizona Professional Land Surveyors achieved a Brave New World by adopting new bylaws including Geospatial Professionals as part of our organization.! Roles of Each Professional! Protection of the Public! State Registration Requirements! Working together to create common goals

August 8, 2004 ESRI Survey & GIS SummitSlide 9

Where does Survey Fit in the GIS World?

! Assist in the establishment of the control and parcel base.! Perform data acquisition of the geographic features.! Develop points, lines, polygons, and areas for direct import into the GIS.! Writing of Data Dictionary and Metadata.! Assist in the Planning, Development, and Maintenance of the GIS.! Surveyors can use the GIS to store their data.