Spatial - Ed.com

Hello,

Here are my test results from Hawaii. I will be happy to provide all raw materials including SSF, COR and Geodatabase.

I learned alot but have to move on.  You guys ever get to the Big Island, this park is very nice with great folks, and a beautiful beach. http://www.nps.gov/kaho

Just for one more clarification.

These tests are not out to disprove of the use of NAD83HARN in Hawaii, nor simply conversion over to NAD83 (PACP00) EPOCH 2003.  These tests simply suggest a Trimble GPS user that is using submeter(now 20cm) gear that in order to post-process against your fine CORS network and work within the automated Trimble base station lists and export to "NAD83" based GIS systems, then the new parameters will satisfy those results.  Neither Trimble nor ESRI can handle 14 parameter shifters.  Until then, "holding"

the reference frame that CORS identifies as the L1 phase center for its stations (NAD83 (PACP00) EPOCH 2003.0 is a fine way for a GIS to bind him/her self to the same reference frame of CORS (but at the date of 2003.0).  Also, the very fine NDGPS system in place throughout the Hawaiian Islands transmit corrections on this same reference frame, allowing a very elegant, real-time storage method of GIS datasets that can store a mixture

of both systems without any discrepancy in reference frames – now that is powerful.

It is the opinion of this author (i play a Geodesist on TV) that tagging data from the workflow below as NAD83 HARN for Hawaii will confuse and confound future use of submeter GPS, since a user could mix the two shifters causing relative locational drift over time in a GIS.  No matter what, remaining consistent, holding CORS, and using metadata tagging our data to a certain EPOCH is our best hope for using this outstanding technology for GIS and Surveying communities.

Credit must be given to the following:

Lisa Marrack - On-Ground GPS tester

Sallie Beavers - RM manager KAHO

Sandy Margriter - Geographer - Hawaii National Parks

Tim Smith - GPS Coordinator for NPS- Denver CO

Michael Dennis - PLS - Arizona (Geodesist)

Richard Snay - PhD. - Silver Spring (Geodesist for NGS)

(See attached file: GPS Tests- Hawaii March 26, 28 2009.pdf)

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Joel Cusick

National Park Service

GIS Specialist/Alaska Regional Office

240 West. 5th Avenue, Anchorage, AK - 99501

(907) 644-3549  
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+61 13' 01.28", -149 53' 10.58", (NAD83 CORS96 EPOCH 2002.0)

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Hello,

I just wanted to let you know that we will be testing various submeter and subfoot (H-star/Zephyr) GPS mapping systems on OPUS generated control at Kaloko-Honokohau National Historical Park during a Trimble course next week.  We will be happy to share with the user community the results of our findings.

As we have discussed with several email threads, the National Park Service's GIS standards for archiving data on Hawaii is UTM Zone 5, NAD83. As defined as such, we will be postprocessing all of our data and tying to nearby CORS stations (MLO1 and others).  In our Pathfinder Office workflow, this means we will be holding the ITRF2000 (EPOCH 1997.0), position and exporting to ESRI shapefile format using modified 7-parameter NAD83 PACP00

Datum parameters that have been identified in this EMAIL Thread document.

In other words, the National Park Service in Hawaii will be "tagging" their data more precisely as "NAD83 UTM Zone 5  for ITRF2000 at time 1997.00 to NAD83 at time 2003.0 as defined by the CORS network.  These 7 parameters are not yet in the Trimble Coordinate System Definition with latest version (4.1), but all class participants will have these available for export to

shapefile.    These 7 parameters are neither found in ArcGIS or ArcPad workflows.  We have developed a datum configuration file (GTF file) called ":NAD_1983_WGS_1984_PACP00" for use within the ArcGIS workflow.  As of ArcGIS 9.3, the most "modern" datum shifter Though class participants will not need to shift data from within ArcGIS (the shapefiles will already be

defined as UTM Zone 5, NAD83 PACP00 (EPOCH 1997.0), those who wish to independently tests such shifts within the ArcGIS environment have an opportunity to do so.

Anticipated Tests from Class:

I'll be teaching a 3.5 day Trimble GPS class on the Big Island next week. Our class runs from Tuesday, March 24 - Friday, March 27.  We will be collecting data at Kaloko-Honokôhau National Historical Park www.nps.gov/kaho and our class on Thursday 3:00pm will be occupying OPUS derived control at either Kalokoa fishpond or Kalokoa fishtrap areas.  The OPUS control data was data collected by Tim Smith in Feburary 2009 at KAHO using a geodetic GPS receiver. Data was sent to NGS OPUS for production of

coordinates for main control point (1690183a or KAHO_Control near the visitor's center). OPUS generated ties to 3 nearby CORS stations was used. KAHO_Control was occupied for the duration of a real-time kinematic (RTK) data collection of additional relative control or RTK points at Kaloko Fishpond and Ai Opio Fishtrap areas.  RTK control points were collected using an occupation time of 5 seconds.  Data provided for testing were

exported in UTM Zone 4, NAD83 (PACP00), EPOCH 2003.0).  Data for class was

transformed from UTM Zone 4 to UTM Zone 5.  No datum transform conducted. Students on Thursday will be collecting averaged point features (30 positions per point at 1sec. logging interval).  As with all of our classes, we will compile the independent test results from all 14 students who will be using TerraSync 3.3 on all devices.  GPS units will range from ProXR/NDGPS beacon receivers, to GeoXH2008, GeoXT 2005/2008, JunoSB.  We

will have a unique opportunity to validate Trimble accuracy specifications for all gear types as well as intentionally shift data between  reference frames relative to NAD83 PACP00 EPOCH 2003.  NDGPS beacon gear will provide a great test of realtime occupation using the NAD83 PACP00 Epoch 2003)

realtime signal as well as other systems utilizing WAAS (in the ITRF00(Epoch current) reference frame.

Since teaching the class is number one mission, little time will be spent on rigorous statistical testing, but our intent of all student tests is to work within the constraints of the software we use today and validate such data against control tied to the CORS reference frame.

We are aware this approach does not address motion of the Tectonic plate relative to ITRF2000, but neither can our software do this.  So, its left up to documenting our process thru metadata.  So our tests will " test the

PACP00 datum transformation parameters for ITRF2000 at time 1997.00 to NAD83 at time 2003.0 as defined by the CORS network.

I will make all of my test data available to anyone.

Wish us luck...  this stuff makes my head hurt.

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Joel Cusick
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