​​​​​Announcing a one-day workshop:

Space, Time, and Datum Forensics: A Geodetic Workshop

by Michael Dennis

and sponsored by

The Oregon GPS Users Group

When:            Thursday, March 10, 2016  7:30am-4:30pm
Where:           NW Eola Viticulture Center of Chemeketa C.C.

                        215 Doaks Ferry Rd., Salem, OR 97304
Lunch:           Yes, tasty lunch is provided
Check-in:       7:30-8:30 AM (Pre-registration only—No registration at the door)
PDH Credits: 7

Click here to download presentation prior to your attendance.

​What do you do when your horizontal control monuments are NAD 83 (1998), your field work is NAD 83 (2011) epoch 2010.00, and the client requires NAD 83 (1991) deliverables? Which geoid model should be used with the different horizontal datums?  How do you set up a long-term project in light of the fact that new horizontal (geometric) and vertical datums will be defined and adopted by NGS within the next 8 years? How does all this work with the Oregon Coordinate Reference System low-distortion projections? What is the difference between NAD 83, IGS08, ITRF2008, and WGS 84? What software tools are available?

First come, first served for up to 150 registrants. Cost is $75 and includes buffet style lunch. Attendees will be emailed any handout materials a few weeks before the workshop and should be self-printed prior to your attendance. No handout materials will be provided at the workshop.

 Michael L. Dennis, RLS, PE, is owner of Geodetic Analysis, LLC.  His firm provides geodetic and GIS consulting services, including coordinate system design, GNSS processing, control network adjustments, and survey-GIS data integration.  Mr. Dennis is also a geodesist at the National Geodetic Survey currently on leave while pursuing a PhD in geomatics engineering and GIS at Oregon State University. While at NGS, Mr. Dennis managed the National Adjustment of 2011 Project, and as a consultant he was instrumental in helping define the low distortion projections used for the Oregon Coordinate Reference System.

Questions: johnminor3537@gmail.com or 

Chris Munson at chris@munson-assoc.com

Click here for printable PDF registration document

Send one registration per person to:           

Chris Munson

233 Southwest Wilson Ave., Ste.5 

Bend, OR 97702

Make Checks payable to: Oregon GPS Users Group
OGUG tax ID# 93-1282014 

All Special Events will be archived here for future reference. ​

Past Special Events

Oregon Coordinate Reference System
A workshop presented by
The Oregon GNSS User’s Group , Umpqua Community College Oregon Department of Transportation Geometronics Unit

March 3, 2017 Announcement

Members & Friends,

 Michael Dennis of the National Geodetic Survey (and fellow Oregon GNSS Users Group member) is giving two webinars on the transition of State Plane Coordinates to the new and upcoming Terrestrial Reference Frames of 2022.  The first webinar is this Thursday, March 8; the second webinar will build upon the first, and be held on April 12.  More information along with registration links are below, or you can visit the NGS website directly here: 


For those who attended the Geodetic Workshop provided by Michael Dennis, there is a new version of the presentation that was revised on March 17, 2016.  The most significant revision to the handout is on p. 22 for computing distance using the local geodetic horizon approach. He corrected minor math errors on that page and also changed and added additional information.  You can download the handout here (PDF).  There is an accompanying PowerPoint presentation, but is too large to attach.  You can go to this link and download it here.

There is also a Certificate of Attendance you can download here.

High-Precision GNSS in a Four Constellation World

When: Monday, April 22, 2019 8:30am-4:00pm
Where: Chemeketa Eola—NW Wine Studies Center: 215 Doaks Ferry Rd. NW, Salem, OR 97304
Lunch: Yes, tasty lunch is provided
Check-in: 7:30-8:30 AM (Preregistration only—No registration at the door) PDH Credits: 7
Cost : $60 members/$80 non-members

To download a Certificate of Completion for this workshop, click here.

When: March 15, 2017, Wednesday, 7:30am-4:30pm 

Where: Umpqua Community College
1140 Umpqua College Rd.
Danny Lang Center, Rooms 203-204
Roseburg, OR 97470

Lunch: As always, a great lunch is included
Check-in: 7:30-8:30am (preregistration only-no registration at the door)

For a PDF document of the agenda, click here.

PDH credits: 7
Cost: $30 students $45 members $65 non-members


The development of small Unmanned Aerial Systems (UAS) along with lightweight sensors and software have revolutionized aerial mapping. OGUG is pleased to provide Geospatial Professionals in Oregon a chance to witness these technologies in action.

Tuesday August 23, 2016 8:30 am – 4:00 pm

NW Eola Viticulture Center of Chemeketa C.C.

215 Doaks Ferry Rd.

Salem, OR 97304

Registration Fee: Members $25 / Non-members $75 PDH Credits: 6
(Hint: Consider becoming a member for $12!)

Coffee, pastries and catered lunch (sandwich) provided.

Click here to get the Certificate of Attendance

Click here for workshop flyer


You can download Eric Gakstatter's presentation here

You can download Chase Fly's presentation here