SRCW Standards and Specifications

This page describes SRCW recognized standards and specifications
pertaining to precise positioning and geodetic grade GPS and surveying
applications. To ensure that the greatest benefit is achieved for all of
Washington State's positioning community, the SRCW will be encouraging, and
frequently, requiring these high standards be met for work that it contracts.
This page is currently under construction and subject to modification.

GPS Antenna Mounts

Exposed Bedrock or Outcrops
Use the Short Drilled Braced Monument at locations where there is exposed (surface)
bedrock or within 0.5m of the surface. The ideal bedrock condition should be
fresh or slightly weathered and minimally fractured/jointed. The depth to which
the legs are set should allow the monument to be anchored within solid bedrock.
If weathering and/or fracturing occur too deeply then the bedrock is not
suitable for this monument.

Unconsolidated Soils
The Deep Drilled Braced Monument provides for a high degree of stability and
longevity and can be anchored in bedrock or unconsolidated material. It is in
the form of a tripod, each leg extending into the ground up to about 40 feet and
welded at the top with gusset reinforcements. If site access is an issue, the
Short Drilled Braced Monument is the next best alternative to this type.

Before You Dig

If you're planning to dig to a depth of 12 inches or more, even on your own property,
Washington State law requires that you notify the Utilities Underground Location Center.
Call toll free 1-800-424-5555 at least 2 business days before you dig. Each utility will come out to mark the location of its underground utilities with the following colors:

Specifications: Policy & Guideline

NGS

• Bluebook Policy
• Project Proposal Form

GPS Observations

Federal Government NGS Guide for GPS Observations Guidelines for establishing GPS-derived ellipsoid heights

Washington State GPS Guidebook
Standards and Guidelines for Land Surveying Using Global Positioning System Methods

Digital Bar Code Leveling
Laser Levels Guide
Leveling Requirements

NOAA Technical Memorandum
NOAA Technical Memorandum on Precise Leveling Corrections


Leveling Equipment

Equipment List and Sources

Precise Leveling Equipment for Second Order, Class I Levels

• Leica DNA03 digital level, Purchased from Kuker Ranken;

• 1ea 714-502 Invar Bar code rod set, calibrated, w/shipping case & centering shoe’s and stays, Purchased from Kuker Ranken

• 1ea 563-733 60cm Invar Bar code strip (GWCL60), Purchased from Kuker Ranken;
                   

Additional Equipment to meet NGS specifications

• 1ea Turning pins (NGS Specifications), Purchased from Ryker Machine & Welding, Inc.
              
• Reference foot for the 60cm Invar Bar code strip (GWCL60), Purchased from Ryker Machine & Welding, Inc.
              
• 7.0 KG "Turtle" Leveling Base Plate for Leica GPCL3 Invar Bar Code Rod, 3-legged Turtles 8” dia. (made from 1” steel plate) with Rounded Center pin (?” dia. by 1¼”) and carrying handle. Finished weight, =15 lbs. Legs are drilled and taped ?”x 11 stainless pointed bolts. See picture. Purchased from Streich Brothers, Inc.
                             
• Thermistors are hard to find but Gary Perasso, our state advisor has two sets built by NGS. Mr. Perasso willingly allows use of them to accomplish Height Modernization goals.
             
• Neodymium Magnets .500x.500, ND 151N-35 and .500x 1.000, 10 ND 501N-35. Magnets for the end of the Invar rods. (NOTE: Be sure to use the same magnet coming up off the monument and going back onto the monument.) Purchased from Master Magnetics, Inc.
    
• Tri-Max Fixed Leg Tripod #90570 by Crain, Purchased from Portland Precision Co., Inc.

Equipment Manufacturers

Backup Recording Sheet Version 1

Backup Recording Sheet Version 2

Survey Station Description Form (blank)

Survey Station Description Form (sample, filled out)

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