Tools to help complete “Height Mod” Surveys OPUS & OPUS Projects Joe Evjen, Geodesist, NGS Height Modernization Eastern States Regional Tuesday, March 04, 2014 Webinar

options: projects & publishing your solution mark description IGS & NGS base stations & site information files IGS antenna calibrations & satellite orbits & reference frames UNAVCO teqc converter PAGES baseline processor var. geophysical models NGS geodetic toolkit IGS & NGS base stations & site information files IGS antenna calibrations & satellite orbits & reference frames UNAVCO teqc converter PAGES baseline processor var. geophysical models NGS geodetic toolkit your GPS data standard geodetic data OPUS O nline P ositioning U ser S ervice JGE 2013 v1 free, fast, easy, consistent coordinates geodesy.noaa.gov/OPUS

Static: OPUS determines your position with a differential GPS static solution, using hours of data. This process is repeated 4x from other CORS. baseline 1 baseline 3 baseline 4 baseline 2 baseline 5 NO BENCH MARKS … is this a height mod survey?

OPUS report From: opus Subject: OPUS solution : nji o.txt OP NGS OPUS SOLUTION REPORT ========================... SOFTWARE: page master43.pl START: 2010/01/01 00:00:00 EPHEMERIS: igs15645.eph [precise] STOP: 2010/01/01 01:59:00 NAV FILE: brdc n OBS USED: 5443 / 5579 : 98% ANT NAME: 3S-02-TSATE NONE # FIXED AMB: 34 / 35 : 97% ARP HEIGHT: OVERALL RMS: 0.010(m) REF FRAME: NAD_83(2011)(EPOCH: ) IGS08 (EPOCH: ) X: (m) 0.002(m) (m) 0.002(m) Y: (m) 0.004(m) (m) 0.004(m) Z: (m) 0.005(m) (m) 0.005(m) LAT: (m) (m) E LON: (m) (m) W LON: (m) (m) EL HGT: (m) 0.006(m) (m) 0.006(m) ORTHO HGT: (m) 0.016(m) [NAVD88 (Computed using GEOID12A)] UTM COORDINATES STATE PLANE COORDINATES UTM (Zone 18) SPC (2900 NJ )... Northing (Y) [meters] Easting (X) [meters] Convergence [degrees] Point Scale Combined Factor US NATIONAL GRID DESIGNATOR: 18TWL (NAD 83) BASE STATIONS USED PID DESIGNATION LATITUDE LONGITUDE DISTANCE(m) DI3830 NJTP PISCATAWAY CORS ARP N W DI0616 NYQN QUEENS CORS ARP N W DH3768 NJMT NJMT CORS ARP N W NEAREST NGS PUBLISHED CONTROL POINT AJ3348 NJ INST OF TECH 2 CORS ARP N W

OPUS uses GEOID12A to convert ellipsoid height to NAVD 88 How good is it?

DSWorld displays GEOID12A accuracy estimates

OPUS RULE OF THUMB: 1 σ = 4 cm 2 σ = 8 cm Bad survey? bad marks? bad OPUS?

OPUS-projects : first, run OPUS to harvest all project data OPUS automatically forms sessions from simultaneously observed marks, enabling multi-baseline processing and adjustment of redundant observations. Improved solutions for simultaneous or repeated observations harvest data from multiple observers share upload & processing tasks customize your processing using PAGES simple data quality analysis improve survey accuracy constrain to local networks publishing support (limited)

Why complicate OPUS? OPUS Projects10 HATFIELD MCCOY ObservationSessionAdjustment OPUS solutions

Why complicate OPUS? OPUS Projects11 session 001 OPUS solutions HATFIELD MCCOY ObservationSessionAdjustment

Why complicate OPUS? OPUS Projects12 session 002 session N session 001 OPUS solutions HATFIELD MCCOY ObservationSessionAdjustment

Why complicate OPUS? session 002 session N session 001 network adjustment OPUS solutions HATFIELD MCCOY ObservationSessionAdjustment

What’s all that really mean for me? OPUS solutions= pretty good, but each treated as independent and assumes “perfect” CORS. Sessions= simultaneously-observed marks processed together in sessions increases consistency. Adjustments= interlinking sessions through network adjustments increases accuracy OPUS Projects14

OPUS Projects15 geodesy.noaa.gov/OPUS is the access point for all things OPUS NGS > OPUS

OPUS Projects16 “Options” allows any user with your project id to add data NGS > OPUS > options

NGS > OPUS > options > project ID > upload mark description … and a mark description.

OPUS Projects18 the “Projects” link NGS > OPUS

OPUS Projects19 … launches the OPUS Projects gateway page NGS > OPUS > projects

Limitations? Uploads through OPUS-Static. – Dual-frequency. – 2 hrs ≤ data span ≤ 48 hrs (≤ 2 GPS midnights). – Observation interval = a factor of 30 (seconds). Minimum project size. – None Maximum project size. – There are practical limits to a project’s maximum size. – About 100 marks in a single session. – Number of data files < a few hundred Introduction20

OPUS Projects21 OPUS Projects Training Because of its increased complexity, training is required to be an OPUS Projects manager. These workshops are usually two day in length and small so that there is ample time for one-on-one interaction with the instructor. Check the NGS training center schedule for upcoming workshops run by NGS

Things To Come. OPUS Projects improves because your criticisms and suggestions. Although we can’t act upon every comment, we do appreciate and consider every one. They have and will continue to steered development. Here are a few things already in the works: Allowing data files < 2 hrs in duration. Better integration with CORS. Better support for publishing to the NGSIDB Introduction

User guide in final development