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- . Specification 
- A Producers documentation requirements. 
The control of these elements is described with respect to: 
- Sampling strategy 
-  Accept/reject rules 
- Quality control method. 
Following products are defined: 
- Aerial Photography and Ground Control Points 
- Scanned Photo 
- Aerial Triangulation 
- Topographic Data 
- Digital Terrain Model (DTM) 
- . Topographic map in scale 1:25000 (TK25) 
- Digital orthophoto in scale 1:5000 (DOF). 
1. Quality Plan 
Quality Plan defines the organization, policies and procedures 
applied by CGI when undertaking quality control of product 
deliverables. Developing and inspection plan and execution 
describes how individual inspections are planned and 
undertaken. Inspection of a product may consist of many 
individual inspections. 
Developing of inspection plan describes the steps to follow 
when developing an Inspection Plan. The result of this 
examination shall be written in the Inspection Plan for the 
Project. The same Inspection Plan template can be used over 
again for new projects of similar nature. 
Execution shows the steps to follow when undertaking the 
Inspection Work. The inspection itself must be new for each 
project however the procedure can be the same for similar 
projects. 
a) The development of a control plan follows the next six 
steps: 
- Identification of dataset 
When identifying the dataset, the relevance of the data should 
be emphasized. 
- Identification of data quality elements 
The control might involve one or more quality elements. The 
control plan will identify all data quality elements and data 
quality sub elements relevant for the product or service. 
- Identification of data quality measure 
The data quality measure has to be defined. 
- Identification of tolerances 
Requirements for geographic information specified as tolerance 
are standard parts of the specifications for the data set. 
- Identification of data quality scope 
The geographic area for the control and groups of objects has to 
be identified. A choice has to be done between full inspection 
and sampling. If sampling is chosen, the size of the scope and 
geographic location has to be identified. 
- Identification of control method 
The control method has to be defined. 
b) Execution of inspection contains the following: 
- Undertake control measurements and calculate Values 
for data quality measures 
True values must be obtained, usually by control measurements. 
Corresponding values are selected from the dataset. The 
difference between the value of the dataset and the true value is 
the discrepancy. Based on all differences, the value for the 
current quality measure can be evaluated. 
- . Compare calculated values for quality measures with 
tolerances. 
Values from the control measurements shall be compared with 
the tolerance of the data quality measure. It has to be decided 
whether the quality corresponds with the product specifications 
169 
or not. The result must be significantly worse than the tolerance 
before the dataset is rejected. 
- Approval and handling of gross errors/discrepancies 
When the control is finished, it has to be decided whether the 
dataset shall be approved, rejected or if the control shall be 
expanded. 
- . Reporting 
Reporting can be done in two ways: 
- Prepare a special inspection report 
- . Report as metadata. 
It is recommended to report by means of inspection reports. 
1.3 Procedures and Checklists 
A Checklist is a Formal description of a task mainly built up of 
boxes to be filled in, ticked or signed. 
All Procedures and Checklists are controlled by a system of 
sponsor and custodian where both signatures are required 
before the documents are released for use. Custodians are 
responsible for the distribution and revision control of all 
documents assigned to them. Sponsors authorize the content of 
the document for use. As a general rule, sponsors are 
departmental managers. 
Data quality methods are divided into two main classes, direct 
and indirect. Direct methods determine data quality through the 
comparison of the data with internal and/or external reference 
information. Indirect methods infer or estimate data quality 
using information on the data such as lineage. The direct 
evaluation methods are further sub classified by the source of 
the information needed to perform the evaluation. 
a) Direct Evaluation Methods 
- Types of Direct Evaluation Methods: internal and 
external. 
- J Means of Accomplishing Direct Evaluation: for both 
external and internal evaluation methods, there are 
two considerations, automated or non-automated and 
full inspection or sampling. 
- Full inspection 
- Sampling 
b) Indirect Evaluation Method 
The indirect evaluation method is a method of evaluating the 
quality of a dataset based on external knowledge. This external 
knowledge may include, but is not limited to, data quality 
overview elements and other quality reports on the dataset or 
data used to produce the dataset. 
1.4. Reporting 
Reporting of Data Quality Evaluation Information is possible 
as: 
- . Reporting in Metadata 
- . Reporting in a Quality Evaluation Report 
- Reporting Aggregated Data Quality Result. 
It is recommended to report by means of Inspection Reports. 
2. TEST QUALITY CONTROL OF TOPOGRAPHIC 
DATA 
Before the end of Project CGI has preformed test quality 
control of topographic data. Preliminary tasks that are done can 
be described as: 
- Verification of existing data according to CROTIS 
(State Geodetic Administration, 2002) 
- Data upgrade specification (PMM, 2003) 
- Quality control of upgraded data.