CLACKAMAS GPS TEST NETWORK

MT. HOOD NATIONAL FOREST, NW OREGON


DESCRIPTION:

Clackamas GPS Test Network provides a site for testing P and C/A Code (resource grade) GPS receiver performance under moderate to heavy western oregon timber canopy. The vegetation at the site consists of Douglas Fir and Western Hemlock overstory (approximately 24-40" DBH), with a Vine Maple and Red Alder understory. The terrain at the site is nearly flat. The Test Network consists of thirteen points with geographic positions established by GPS and conventional geodetic survey. These thirteen points are used to define five areas which range from 2.19 to 7.20 acres. Geographic positions for the network points are accurate to 5 cm. Each point is monumented with 5/8" rebar with plastic caps and a nearby orange carsonite fence post, with "survey monument" sticker attached. All points are intervisible and the lines between the survey points have been brushed and flagged.

SITE DIAGRAM AND CLICKABLE THUMBNAIL IMAGES OF SITE:

Image descriptions: 1) At Pt 6 looking toward Pt 7. 2) Data logging at Pt 3B. 3) At Pt 2A. 4) Data logging at Pt 7.
1) 2) 3)
4)

LOCATION AND HOW TO REACH:

The Clackamas GPS Test Network is located approximately 70 road miles southeast of Portland Oregon, on the Clackamas Ranger District of the Mt. Hood National Forest. Directions to the network are: To reach the test network, from the junction of Interstate 205 and State Highway 224 drive easterly on Hwy 224 for approx. 3.5 miles to the junction of State Highways 224 and 214; Turn Right on to Hwy 224 and drive easterly for 14 miles to Estacada, Or; Continue SE on Hwy 224 for 25 miles (note that mileage may now be less due to road realignment) to the junction with Forest Service Road 46 at Ripplebrook Camp Ground; Take the Right fork and continue southeasterly on Forest Service Road 46 for 13.2 miles total to an unsigned dirt road on left; Turn left and continue on dirt track for approximately 100 yards to where the road is blocked. There is an open area here on the left to park in. Continue on foot along road for about 200 yards more, into trees and the test net. Point 2 of the test network is on the right side of road with orange carsonite fence post. Travel time from the downtown Portland is approximately one hour and forty five minutes. The nearest food and lodging are in Estacada, Oregon

NOTE: Point number 3 is has been reported missing. The approximate location is identifiable +/- 1 ft is identifiable just south of the fiberglass post.

REFERENCE STATION INFORMATION:

The closest reference station for differential corrections is the Portland Community Base Station (CBS)
which is located 83.8 KM ( 52.13 mi) from the site. The Portland CBS is a 12 channel Trimble Community Base Station logging SYNC measurements at 5 second intervals.
The nearest CORS station is "APPLETON" providing broadcast RTCM SC 104 differential corrections at 300 KHz , 100 baud rate. CORS station Appleton is located 97 KM from this site. Post process RINEX 30 second interval data is available from the National Geodetic Survey CORS Page.

INFORMATION:

For further information, contact Ken Chamberlain, BLM, Oregon State Office, 333 SW First,

Portland, OR 97204; Phone 503-808-6397.


View Clackamas Testnet station coordinates in Lat/Long, UTM, and State Plane Coords, with polygon acreages
There is a National Geodetic Surveyt High Accruacy Reference Station "ESTACADA" in the town of estacada. THis station can be used as a "control group" for GPS accuracy tests. Horizion at this station is completely unobstructed. The control info from NGS is:
 AI1994 ***********************************************************************
 AI1994  CBN         -  This is a Cooperative Base Network Control Station.
 AI1994  DESIGNATION -  ESTACADA
 AI1994  PID         -  AI1994
 AI1994  STATE/COUNTY-  OR/CLACKAMAS
 AI1994  USGS QUAD   -  ESTACADA (1985)
 AI1994
 AI1994                         *CURRENT SURVEY CONTROL
 AI1994  ___________________________________________________________________
 AI1994* NAD 83(1998)-  45 17 54.70673(N)    122 19 57.14353(W)     ADJUSTED  
 AI1994* NAVD 88     -       154.32   (meters)     506.3    (feet)  LEVELING  
 AI1994  ___________________________________________________________________
 AI1994  X           -  -2,403,623.478 (meters)                     COMP
 AI1994  Y           -  -3,797,379.818 (meters)                     COMP
 AI1994  Z           -   4,510,840.457 (meters)                     COMP
 AI1994  LAPLACE CORR-           5.44  (seconds)                    DEFLEC99
 AI1994  ELLIP HEIGHT-         131.67  (meters)          (04/24/00) GPS OBS
 AI1994  GEOID HEIGHT-         -22.67  (meters)                     GEOID99
 AI1994
 AI1994  HORZ ORDER  -  A
 AI1994  VERT ORDER  -  THIRD ?
 AI1994  ELLP ORDER  -  THIRD     CLASS I
 AI1994
 AI1994.The horizontal coordinates were established by GPS observations
 AI1994.and adjusted by the National Geodetic Survey in April 2000.
 AI1994.This is a SPECIAL STATUS position.  See SPECIAL STATUS under the
 AI1994.DATUM ITEM on the data sheet items page.
 AI1994
 AI1994.The geoid height was determined by GEOID99.
 AI1994
 AI1994;                    North         East     Units   Scale      Converg.
 AI1994;SPC OR N     -   182,965.092 2,356,289.422   MT  0.99989714 -1 17 58.6
 AI1994;UTM  10      - 5,016,330.795   552,332.166   MT  0.99963367 +0 28 27.9
 AI1994
 AI1994                          SUPERSEDED SURVEY CONTROL
 AI1994
 AI1994  NAD 83(1991)-  45 17 54.70485(N)    122 19 57.14281(W) AD(       ) B
 AI1994  ELLIP HT    -         131.81  (m)           (10/13/99) GP(       ) 3 1
 AI1994
 AI1994
 AI1994                          STATION DESCRIPTION
 AI1994
 AI1994'DESCRIBED BY CLACKAMAS COUNTY OREGON 1998 (CHH)
 AI1994'THE STATION IS LOCATED IN THE NORTH PART OF ESTACADA, ON THE NORTH
 AI1994'SIDE OF ESTACADA HIGH SCHOOL.  OWNERSHIP--ESTACADA HIGH SCHOOL, 355 NE
 AI1994'6TH AVENUE, ESTACADA, OR 97023.  CONTACT WILLIAM R. PACKARD, BUSINESS
 AI1994'MANAGER, ESTACADA SCHOOL DISTRICT CENTRAL OFFICE, PO BOX 519,
 AI1994'ESTACADA, OR 97023.  PHONE 503-630-8521.  TO REACH THE STATION FROM
 AI1994'THE INTERSECTION OF STATE HIGHWAYS 224 AND 211, LOCATED IN THE SOUTH
 AI1994'PART OF ESTACADA, GO NORTHWEST ON HIGHWAY 224 FOR 0.24 KM (0.15 MI) TO
 AI1994'THE INTERSECTION OF SE MAIN STREET.  TURN RIGHT, NORTH, ON MAIN STREET
 AI1994'FOR 1.05 KM (0.65 MI) TO THE T-JUNCTION OF NE 6TH AVENUE.  TURN RIGHT,
 AI1994'EAST, ON 6TH AVENUE FOR 0.16 KM (0.10 MI) TO THE FIRST ENTRANCE INTO
 AI1994'THE ESTACADA HIGH SCHOOL PARKING LOT ON THE LEFT.  TURN LEFT, NORTH,
 AI1994'THROUGH THE PARKING LOT FOR 0.08 KM (0.05 MI) TO THE NORTH END.  TURN
 AI1994'RIGHT, WEST, THROUGH THE PARKING LOT FOR 0.08 KM (0.05 MI) TO THE WEST
 AI1994'END.  TURN RIGHT, NORTH, ON DRIVE PASSING BETWEEN HIGH SCHOOL BUILDING
 AI1994'ON THE RIGHT AND ESTACADA SCHOOL DISTRICT CENTRAL OFFICE BUILDING ON
 AI1994'THE LEFT FOR 0.08 KM (0.05 MI) TO A GATE.  PASS THROUGH GATE
 AI1994'CONTINUING NORTH ON GRAVEL SINGLE LANE ROAD FOR 0.24 KM (0.15 MI) TO
 AI1994'AN EAST-WEST CHAIN LINK FENCE THAT IS ON THE SOUTH SIDE OF AN OPEN
 AI1994'DRAINAGE DITCH AND THE STATION TO THE RIGHT.  THE STATION IS AN
 AI1994'ALUMINUM COUNTY SURVEYOR DISK SET IN TOP OF A 30 CM ROUND CONCRETE
 AI1994'MONUMENT FLUSH WITH THE GROUND.  IT IS 26.2 M (86.0 FT) EAST FROM THE
 AI1994'CENTER OF THE GRAVEL ROAD, AND 4.7 M (15.4 FT) SOUTH FROM THE CHAIN
 AI1994'LINK FENCE.


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