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Figure 7: Maritime scenario data capture methodology Figure 6 and Figure 7 above show the process used to extract data from the previously identified data collection
points. There are two points where data is extracted from storage. The first is directly exported from the PostGIS database using standard SQL queries and formatting the output into CSV. The second used standard WFS calls
to get the data from the PostGIS database in a GML application format and convert that content into a CSV format.
The result of the data capture is a set of three CSV files: base data, PostGIS data, and WFS data, which was used for comparison to determine if accuracy and precision errors were introduced by the NIEM XML or the
processing of the data.
Additional details on the experiment process and data flow are included in APPENDIX B: Experiment Data Flow Description.
6.6.4 Data Comparison Methodology
The results of the position data comparison are provided in Appendix G, while Figure 8 provides a graphic
illustration of the process. During the position data comparison, three sets of data e.g., P6, P10, P13 were compared from four different
message constructs e.g., position report, call for fire, observation report, vessel position report from three data collection points e.g., base, database, OWS for two runs e.g., w NIEM XML, wo NIEM XML in two
scenarios e.g., land, maritime. The data sets are described in Section 6.6.2; the data collection points are described in Section 6.6.3, a sample vessel position report instance is provided in Appendix H and I, and the
scenarios are described in Section 7.
The land based position reports, call for fire and observation reports contain material subject to the U.S. International Traffic in Arms Regulations and are therefore not included in this report.
The data analysis included the following comparisons sequenced in the order presented: 1. RUN 1: Base CSV data compared to Database Export CSV of NIEM XML data
2. RUN 2: Base CSV data compared to database export CSV of directly inserted base CSV data 3. Database Export CSV compared to OWS exported GML data converted to CSV
During the data comparison, the sum of the absolute value of the differences in both latitude and longitude were calculated independently and reported.
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Figure 8: Data Comparison Methodology
6.6.5 Developer Skills Required
In order to evaluate the developer skills necessary to work with and implement NIEM based XML exchanges careful consideration was given to the selection of the lead developer to support MOGIE.
The individual chosen had no prior experience with NIEM. In fact, he had not even heard of NIEM before being asked to support MOGIE. His background included:
Undergraduate degree in Computer Science 5 years software development experience; primarily Java
5 years GIS experience 1 year experience writing a WMS, WMTS and KML server for FalconView in C
Experience working with WorldWind Java source code during client testing After agreeing to work on MOGIE, the developer was provided with IEPDs and sample IEPs supporting the land
scenario. Although, these artifacts were derived from previous experimentation and evaluation work with Joint Staff J6 and Esri, they still required modification to be used in MOGIE.
The developer was directed to the NIEM.gov website for technical specifications, tools, and training materials. He was also directed to the NIEM IEPD clearing house as a source for IEPDs that could support the maritime
scenario.
No additional training or technical support was provided. At the conclusion of MOGIE, the developer reported he required 4 days to review NIEM technical specifications
and training before he was ready to begin working with NIEM. Although he reviewed the technical specifications numerous times throughout MOGIE, he reportedly did not require any specialty skills and reported
implementing NIEM XML was no more difficult than implementing any other instantiation of XML in his
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experience.
6.6.6 MOGIE Limits of Precision
