1. What are the three main types of data error?
1. Errors created by faulty processing.
2. Errors created by human error.
3. Errors from obvious sources (e.g. incomplete maps)
4. Errors created during data input (e.g. digitizing).
5. Errors created by map projection.
Errors from obvious sources (e.g. incomplete maps)
Errors created during data input (e.g. digitizing).
Errors created by faulty processing.
2. What are the common problems faced when obtaining data from secondary sources?
1. Expense
2. Availability of suitable data
3. Unknown data formats
4. Unknown lineage
Availability of suitable data
Unknown lineage
Expense
3. Practical problems faced when scanning map documents include:
1. Selection of appropriate tolerances
2. Lack of suitable raster to vector conversion software
3. Possibility of optical distortion
4. Inclusion of unwanted information
Inclusion of unwanted information
Selection of appropriate tolerances
Possibility of optical distortion
4. Which of the following can be a problem in manual digitizing?
1. Dimensional stability of source documents
2. Hand-eye coordination
3. Availability of suitable hardware and software
4. Boredom
5. Inaccuracies in document registration
Inaccuracies in document registration
Dimensional stability of source documents
Boredom
Hand-eye coordination
5. Which of the following methods may be used to input paper maps into a GIS?
1. Scanning
2. Automatic digitizing
3. Manual digitizing
4. Keyboard entry
5. Tracing
Scanning
Automatic digitizing
Manual digitizing
1. The process by which raw spatial data is processed into an integrated GIS database
2. The flow of data from one user to another
3. The flow of data from producer to GIS
4. The process by which maps are transferred between GIS platforms.
The process by which raw spatial data is processed into an integrated GIS database
7. Which of the following methods may be used to check attribute data for errors?
1. Checking for extreme values
2. Checking for internal consistency
3. Comparing with other datasets
4. Checking for impossible values
Checking for impossible values
Checking for extreme values
Checking for internal consistency
1. The process of matching two adjacent map sheets
2. Projecting map data from one coordinate system to another.
3. Stretching map coordinates to fit a series of known control points.
Stretching map coordinates to fit a series of known control points
9. The Douglas-Peucker algorithm is:
1. An algorithm to discretize line segments
2. An algorithm to search an R+ tree
3. An algorithm to discretize an arc
4. An algorithm to triangulate a polygon
An algorithm to discretize line segments
1. True
2. False
True
1. True
2. False
False
1. True
2. False
True
14. A cheap flatbed scanner could have an accuracy of 50 - 200 dpi.
1. True
2. False
True
15. RINEX is the abbreviation for Remote Information Exchange format.
1. True
2. False
False
16. DXF and NTF are examples of vector transfer formats.
1. True
2. False
True
1. True
2. False
True
18. A sliver polygon may be the result of the same line on a map being digitized twice.
1. True
2. False
True
19. Repeated generalization will make the boundary of a polygon more precise.
1. True
2. False
False
20. Geocoding is the process of converting an address into a point location.
1. True
2. False
True
21. What is adding and deleting fields in GIS?
Fields define feature attributes. Most GIS programs provide a way for you to add or delete fields from within your open data file. GIS program will instruct you to define a new field. You will give it a name and select from options that determine the data format of the values that will be placed into the field. Deleting a field usually involves selecting the field and deleting it.
22. Described deleting records in GIS?
You can delete a single record or a group of records in a data file by first selecting them and then deleting them. Since records are the database representation of features, when you delete records in the attribute file, you are also permanently discarding their spatial representation. The entire feature, graphic and record, is deleted.
23. What are white-space delimited ASCII files in GIS?
White-space delimited ASCII files differentiates fields by the use of one or more spaces. Since spaces separate fields, fields that have no value must be represented by a non-blank code and character attributes cannot contain spaces between words (underscores can be used to separate words). You can open ASCII files in any word processor or text editor.
24. What is Spacequote delimited ASCII?
Spacequote delimited ASCII is a variant of whitespace delimitation, but the attributes containing multiple words are enclosed in double quotes, and consequently, they can contain embedded spaces between words.
25. How Sorting records in GIS Date?
Sorting temporarily rearranges your data file records, so you can view, select, update, or print them in the new sorted sequence. Although the specifics vary by program, you generally choose the field (or fields) you want to sort by. The first sort field arranges, usually in ascending or descending order, the records based on the field's contents. For example, a class roster might be sorted alphabetically by last name. Some systems allow you to choose a second sort field (or more), which arranges records (in ascending or descending order) when two or more records have the same first field value. If your alphabetical list has four students with the last name Maria then those four records could be rearranged in alphabetical order based on their first name.
