Meeting Minutes

NCGPSUG

Northern California GPS Users Group
Text Box: NCGPSUG Meeting March 13, 2009 Chairman: Robert Nielsen, PLS is our NEW Chairman. chairman@ncgpsug.org Secretary: Duncan Marshall, PLS secretary@ncgpsug.org Committee for Speakers: Bruce A. Joffe, GISP, AICP If you are interested in joining the Committee for Speakers or making suggestions for speakers please contact Duncan Marshall at secretary@ncgpsug.org Introductions: Announcements: Chairman – The NCGPSUG is in need of a webmaster. If you are interested in managing or learning how to run a web site, we have someone willing to get you started. Caltrans Survey Manuals - Caltrans appreciates any comments and suggestions you may have regarding their manuals. Please send them to Robert McMillan, PLS at robert_m_mcmillan@dot.ca.gov (Note: use underscores for spaces) CORS Station “Chabot” has been destroyed by vandals. Robert Nielson – Marti Ikehara from the NGS: Marti confirmed by email that the current version of DSWorld software available on her website IS the most current Here's the link: http://www.ngs.noaa.gov/PC_PROD/PARTNERS/index.shtml There is a new supplemental web page to the NGS site. Marti doesn’t recommend the NGS -> Datasheet -> Mapsearch Instead, try http://www.dot.ca.gov/hq/row/landsurveys/geodetic/ pick “Geodetic Control” in the blue bar. In the bottom of the page, choose the County NAME. This will bring you a page where you can download maps with links to NGS datasheets for Google Earth (.kml) or Arc View shapefile so you can view NGS control in a map environment. If you don’t have Google Earth, you can download “DS World” from http://www.ngs.noaa.gov/PC_PROD/PARTNERS/index.shtml Notes for using this data: Only has NAVD88 – No Vertcon Only NAD83(NSRS 2007) Stations – no non GPS data Not all CGPS operating stations (shown on different page) only what is in NGS database This is a Static Pull (?) – but you can tell that the datasheet is live by checking the current date on the datasheet. (Marti, could you add something about the HVL, H and CORS files?) On the Google and Arc View maps you can click on the symbol (link) and get a datasheet. Geoid 09 is scheduled for release in June OPUS uses the Geoid for orthometric heights. Check the top of any NGS data sheet for a hotlink to a document that defines all the terms used on NGS datasheets. Check your META DATA, your point may not be as good as you think it is! CLSA Conference in San Diego – Mission Bay March 28 - April 1, 2009 Hilton San Diego Resort San Diego, CA CalGIS 2009 April 6 – 9, 2009, Sacramento, California CSRC is doing a 2009.0 adjustment of CORS and 2007.00 coordinates for the CGPS stations that have come online since 2007.00 GPS for Equipment Machine Guidance Speaker - Kevin Akins from Caltrans GPS guidance of heavy equipment allows for almost stakeless construction. Improves machine productivity 20-40% Reduces Survey Costs up to 50% Caltrans – 25% of their Survey work is construction staking Computer screen on equipment shows equipments’ relationship to a calculated surface. Caltrans tests show a tolerance of 0.10’ for dirt and 0.02 for paving, curb and gutter (using total station updating equipment location 20 times per second) This work cannot be done without an electronic file (Surface). Many times surfaces pick up errors as they are translated from one software to a program the equipment understands. Engineers still need an existing original surface to use in their design. Changes to the Design and Construction Process – Contract Language Are the paper plans the same as the electronic file? Are the paper plans the same as the DTM in the original form? Are the paper plans the same as the DTM translated into the contractors machine software? Are the paper plans the same as the plan/design for machine guidance? Intersections are still the most difficult models to make. Include in contract language Create 3D products - (too fast, need to add items from power point) - Caltrans is looking at new software. When is a …… Who decides on Caltrans Projects Contractor Design Construction Office Engineers Resident Engineer Project Manager Local Partner (Comment: Frank Fraser from California Surveying and Drafting A surveyor in Washington has changed his business model and puts in his contract that this is an agreement – If you find an error, you stop – contact the engineer/surveyor to look at and fix the problem.) Caltrans is moving from 2D to 3D How do you not take on extra liability for electronic files? Paper plans are the contract plans. Caltrans machine guidance projects Accuracy Cost savings … … It’s a 3D world Machine guidance is trend toward needing 3D data. Surveying, design and construction are changing. Must have 3D information/plans to improve the process. Quality assurance – Field check design for things such as utilities On site visits to with contractor about control Check out machinecontrolonline.com Speaker – Rob McMillan from Caltrans: Experiments with OPUS Online Positioning User Service Rob is a teacher at Sacramento City College and is currently teaching Survey 499 “Global Positioning Surveying”. He is requesting input for his future work. OPUS – S OPUS – RS OPUS – Database option – 4hrs – Marti Ngs.noaa.gov/opus Trimble has a new program to convert a Trimble data file into Rinex – available on their website OPUS- S If submitting zip files be sure to include the antenna type Options: If you choose to receive extended data you get NAD83 coordinates in feet at the end of the file. CORS – 2002 epoch – Repeatable! Orbits: Broadcast, Rapid and Precise – coordinates will vary slightly Does this meet PRC requirements? (Consensus at meeting was yes backed by metadata – NO DOCUMENTATION! Some still undecided. You still need to look at reports: What CORS stations were used? QC – choose different stations and compare coordinates. OPUS picks 4 nearest CORS stations and checks quality of CORS data. OPUS – RS Processes using 6 CORS sites Uses 4 hours – 48 hours (check). OPUS – DB You need to Register Can choose CORS. Marti says minimum of 4 hours of data Can add data such as photos of site Can be added to National Database To distinguish these new types of points, they will have 4 letters and 2 numbers. Do your OPUS – S before submitting to OPUS – DB. If you submit multiple times, you will have multiple points at the same location. Tell Rob your ideas on how you use: OPUS RTN RTN 3RD Order robert_m_mcmillan@dot.ca.gov (Note: use underscores for spaces)