February 13, 2003 Digital Goverment Minutes

Digital Government Project Meeting Summary

February 13, 2003
1:30 pm in 230 Bolz Hall
RAs only

Appendix A | Appendix B | Appendix C | Future Meetings

Attendees:

OSU Mapping & GIS Lab: Dr. Ron Li, Dr. Ahmed F. Elaksher, Ruijin Ma, Xutong Niu
OSU Center for Mapping: Tarig Ali
OSU Geodesy Laboratory: Chung-Yen Kuo
Great Lakes Forecasting System Laboratory : Vasilia Velissariou
SUNY at Buffalo: Xian Xu (reported by E-mail)

Summary:

Ruijin Ma reported on his work with IKONOS imagery. He has completed manually checking the shoreline points for mismatch. The difference in the shoreline elevations is now within 5 meters.

Xutong Niu is working on converting the USGS DEM vertical datum from NAVD27 to NAVD88. He is also working on checking the accuracy of the shoreline at Marblehead (see Appendix A). He is looking for the position of the gauge station at Marblehead and the position of the shoreline at this location. He has received the software developed by Ruijin that will be converted to ArcGIS.

Dr. Elaksher discussed the requirements for the long paper for the next DG conference. He also made a presentation about simulation of the tide-coordination problem (see Appendix C).

Tarig Ali reported on the shoreline prediction system he is developing for Painesville.

Chung-Yen Kuo talked about generating water surfaces from the satellite altimetry data (see Appendix B). He reported there is a 0.5m difference between the gauge station and altimetry data.

Vasilia Velissariou reported that the numerical water model program is running now for the year 1998. The program has finished the first 100 days and is running the rest of the year.

Xian Xu reported that he was developing the HTTP and FTP downloading part in the remote data access system. Currently he is using C++ and MS.Net. He has already finished a draft version. Asynchronous HTTP downloading is now supported. The program is component based, which means Xutong Niu and Xian Xu can develop at different sites and the later integration of individual parts will be a lot easier than for what they did using Visual Basic.

Action List:

OSU Mapping & GIS Lab

Ruijin Ma will work on visualizing the 3D IKONOS shoreline to represent the elevation differences. He will also work on redoing the interior orientation of the aerial photos for Lake Erie.
Xutong Niu will work on designing a 3D visualization tool for the differences between the coastal model data sets. He will contact Kai-chien (Kevin) Cheng to find the Marblehead GPS coordinates and study the differences between these coordinates and the shoreline.He will also work on converting the software developed by Ruijin to ArcGIS.
Dr. Elaksher will work on the tide-coordination problem.

Center for Mapping

Tarig Ali will work on the visualization of the different metrics in his linear position accuracy metric system and contact Mark Luther to get his numerical water model in Tampa Bay. At the next meeting, he will give a presentation about the shoreline prediction system in Painesville.

OSU Geodesy Lab

Chung-Yen Kuo will work on finding more 2002 altimetry data in Lake Erie from other satellites, convert all vertical data to the NAVD88 datum, and Investigate the difference between the altimetry data and the gauge station data.

Great Lakes Forecasting System Laboratory

Vasilia Velissariou will complete the runs for the numerical water model program and make graphs to show the effect of reducing the output time interval from one hour to ten minutes on the computation of MLLW and MHW.

SUNY at Buffalo

Xian Xu will work on the FTP function as Microsoft doesn’t provide built-in support for FTP data.

Future Meetings

The next co-PI and RA meeting will be Thursday, February 27
The next RA only meeting will be held Thursday, March 13

Attachments

Appendix A: Marblehead: Difference between Shoreline and Gauge Station Positions
Appendix B: Water Surfaces Generated using Gauge Station and Altimetry Data
Appendix C: Simulation Analysis for the Tide Coordination Problem , presentation by Dr. Elaksher (see separate file)

For more information, email: li.282@osu.edu

Appendix A: Marblehead: Difference between Shoreline and Gauge Station Positions
Xutong checked the accuracy of the gauge stations’ coordinates. The coordinates of the stations currently used in the project were obtained from the web site of Center for Operational Oceanographic Products and Services (http://co-ops.nos.noaa.gov/). The accuracy for these coordinates is given up to 0.1 arc minute. Since 1 arc second is about 30m, 0.1 arc minute is about 60 * 0.1 * 30 = 180m. Therefore, horizontal location error for the station is about 180m.

For instance, the coordinates for Marblehead station as given on the web are

Latitude:	41° 32.7' N = 41.5450° N
Longitude:	82° 43.9' W = 82.731667° W

The actual GPS measurements taken by Kevin Cheng are

Latitude:	41.5438° N
Longitude:	82.7309° W

The difference between these two kinds of data are plotted onto a map with the projection UTM, NAD 83 (shown below). The distance between two points is 147.8m.

This picture below shows the Marblehead gauge station. As seen from this picture, the true gauge station should be located close to the shoreline, not offshore as is shown in the above map. The reasons for this disparity are found in the accuracy of the USGS shoreline and the rounding error of the GPS observation.
Marblehead Gauge Station

Appendix B: Water Surfaces Generated using Gauge Station and Altimetry Data