Unit 2 Assignment: Geographic Coordinate System
LAB 2 – Assignment
1. Summarize in your own words the steps you have followed to complete task 1?
Task one design to do a shape file from a geographic coordinate system to a custom projected coordinate system.
Steps followed:
1. Right click idll.shp in the catalog tree, select properties.
2. The X and Y coordinate system tab in the shapefile properties dialog shows the name to be unknown. Close the dialog.
Define the coordinate system for idll.shp.
Open ArcToolbox window to open it in ArcCatalog. Right click Arc tool box and select environment. Select chapter 2 database for the current workspace.
a.i. Double click define projection tool
a.ii. Select idll.shp for the input feature class
a.iii. (the dialog shows it has an unknown …show more content…
"This datum, designated as NAD 83, is the new geodetic reference system. NAD 83 is based on the adjustment of 250,000 points including 600 satellite Doppler stations which constrain the system to a geocentric origin." (Geodetic Glossary, pp 57)
c. In your own words, what is on-the-fly projection?
On-the-fly projection is designed for displaying data sets that are based on different coordinate system.
ArcMap attempts to rectify differences in datum (GCS) and differences in projected coordinate systems (PCS).
User has a choice of the transformation equations to go from one datum to another
Demonstrate by loading data that have a different GCS into new Data Frame. on-the-fly projection work as Every set of data needs a stored GCS and PCS. These comprise the files Spatial Reference. ArcMap read the spatial reference to do on-the-fly projection. Lack of a spatial reference is a common problem for data from the web.
d. What is the different between a geographic coordinate system and projected coordinate system?
Geographic coordinate …show more content…
It uses constant lengths, angles, and areas across the two dimensions.
A projected coordinate system provides various mechanisms to project maps of the earth's spherical surface onto a two-dimensional Cartesian coordinate plane. Projected coordinate systems are referred to as map projections
4. What you learn in the lab 2 exercise?
The first two situations are dealt with in ArcToolbox and result in the creation of a projection file (*.prj), a simple text document containing coordinate information. ArcGIS provides projection files with many predefined coordinate systems. Further we could also create and save a projection file for a new coordinate system. That new file can be used to define or project other data sets.
The third situation happens automatically in ArcMap. When ArcGIS does not know what projection the original data is in (it cannot find the *.prj file) it will assume a “projection on the fly”. This is often not the correct projection, and will cause severe consternation until you discover the
1. Summarize in your own words the steps you have followed to complete task 1?
Task one design to do a shape file from a geographic coordinate system to a custom projected coordinate system.
Steps followed:
1. Right click idll.shp in the catalog tree, select properties.
2. The X and Y coordinate system tab in the shapefile properties dialog shows the name to be unknown. Close the dialog.
Define the coordinate system for idll.shp.
Open ArcToolbox window to open it in ArcCatalog. Right click Arc tool box and select environment. Select chapter 2 database for the current workspace.
a.i. Double click define projection tool
a.ii. Select idll.shp for the input feature class
a.iii. (the dialog shows it has an unknown …show more content…
"This datum, designated as NAD 83, is the new geodetic reference system. NAD 83 is based on the adjustment of 250,000 points including 600 satellite Doppler stations which constrain the system to a geocentric origin." (Geodetic Glossary, pp 57)
c. In your own words, what is on-the-fly projection?
On-the-fly projection is designed for displaying data sets that are based on different coordinate system.
ArcMap attempts to rectify differences in datum (GCS) and differences in projected coordinate systems (PCS).
User has a choice of the transformation equations to go from one datum to another
Demonstrate by loading data that have a different GCS into new Data Frame. on-the-fly projection work as Every set of data needs a stored GCS and PCS. These comprise the files Spatial Reference. ArcMap read the spatial reference to do on-the-fly projection. Lack of a spatial reference is a common problem for data from the web.
d. What is the different between a geographic coordinate system and projected coordinate system?
Geographic coordinate …show more content…
It uses constant lengths, angles, and areas across the two dimensions.
A projected coordinate system provides various mechanisms to project maps of the earth's spherical surface onto a two-dimensional Cartesian coordinate plane. Projected coordinate systems are referred to as map projections
4. What you learn in the lab 2 exercise?
The first two situations are dealt with in ArcToolbox and result in the creation of a projection file (*.prj), a simple text document containing coordinate information. ArcGIS provides projection files with many predefined coordinate systems. Further we could also create and save a projection file for a new coordinate system. That new file can be used to define or project other data sets.
The third situation happens automatically in ArcMap. When ArcGIS does not know what projection the original data is in (it cannot find the *.prj file) it will assume a “projection on the fly”. This is often not the correct projection, and will cause severe consternation until you discover the