DAM2 Site Information Form
     International GPS Service for Geodynamics


0.   Form

     Prepared by (full name)  : Marin Clark
     Date Prepared            : 31-OCT-1997
     Report Type              : UPDATE
     Prepared Using           :


1.   Site Identification of the GPS Monument

     Site Name                : Pacoima Dam #2
     Four Character ID        : DAM2
     Monument Inscription     : None
     IERS DOMES Number        : 49905M002
     CDP Number               : N/A
     Date Installed           : 23-AUG-1995 hh:mm UT
     Geologic Characteristic  : (BEDROCK/CLAY/CONGLOMERATE/GRAVEL/SAND/etc)
       Bedrock Type           : (IGNEOUS/METAMORPHIC/SEDIMENTARY)
       Bedrock Condition      : (FRESH/JOINTED/WEATHERED)
       Fracture Spacing       : (1-10 cm/10-50 cm/50-200 cm/over 200 cm)
       Notes                  : (multiple lines)
     Additional Information   : Antenna is attached to top of a specially built
                              : pier that is approx. 2 m tall so as to put the
                              : the antenna above height of the chain link
                              : fencing that runs the length of the dam crest.
                              : SCIGN - Southern California Integrated GPS
                              : Network


2.   Site Location Information

     City or Town             : North of Sylmar
     State or Province        : California
     Country                  : USA
     Tectonic Plate           : Pacific-North America plate boundary
     Approximate Position
       X coordinate (m)       : -2507655.539
       Y coordinate (m)       : -4638419.625
       Z coordinate (m)       :  3577506.547
       Latitude (deg)         :   34.3348
       Longitude (deg)        : -118.3969
       Elevation (m)          :  584.3994
     Additional Information   : Approximate ITRF92 coordinates. Epoch 1995.75


3.   GPS Receiver Information

3.1  Receiver Type            : ASHTECH Low Power Z-XII Model 700845-6(1)
     Serial Number            : 00225 (Owned by L.A. County Survey Division)
     Firmware Version         : NAV 1E24, CHN 1C70
     Date Installed           : 23-AUG-1995 hh:mm UT
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : First Measurements.

3.2  Receiver Type            : ASHTECH Low Power Z-XII Model 700845-6(1)
     Serial Number            : 00225 (Owned by L.A. County Survey Division)
     Firmware Version         : NAV 1E95, 1D01
     Date Installed           : 06-SEP-1996 hh:mm UT
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : Firmware upgrade.

3.3  Receiver Type            : ASHTECH Low Power Z-XII Model 700845-6(1)
     Serial Number            : 00225 (Owned by L.A. County Survey Division)
     Firmware Version         : NAV 1E95, 1D01
     Date Installed           : 23-OCT-1996 hh:mm UT
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : No changes to rx unit at this time.
3.x  Receiver Type            :
     Serial Number            :
     Firmware Version         :
     Date Installed           : (dd-MMM-yyyy hh:mm UT)
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : (multiple lines)

4.   GPS Antenna Information

4.1  Antenna Type             : ASHTECH Model 700936-A (Metal Choke Ring)
     Serial Number            : 11495 (Owned by L.A. County Survey Division)
     Antenna Height (m)       : 0.0400
     Antenna Reference Point  : BPA
     Degree Offset from North :
     Antenna Radome Type      :
     Date Installed           : 23-AUG-1995 hh:mm UT
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : First Measurements.
                              : Vertical datum is the the machined top surface
                              : of a pier that was built by LA County - they
                              : use top surface of monumnet in dam surface as
                              : their own vertical datum.
                              : (not yet measured)

4.2  Antenna Type             : ASHTECH Model 700936-A (Metal Choke Ring)
     Serial Number            : 11495(Owned by L.A. County Survey Division)
     Antenna Height (m)       : 0.0400
     Antenna Reference Point  : BPA
     Degree Offset from North :
     Antenna Radome Type      :
     Date Installed           : 06-SEP-1996 hh:mm UT
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : No changes to antenna at this time.

4.3  Antenna Type             : ASHTECH Model 700936-A (Metal Choke Ring)
     Serial Number            : 13539 (Owned by L.A. County Survey Division)
     Antenna Height (m)       : 0.0400
     Antenna Reference Point  : BPA
     Degree Offset from North :
     Antenna Radome Type      :
     Date Installed           : 23-OCT-1996 hh:mm UT
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : Antenna swapped; preamp overloaded on previous
                              : antenna.

4.x  Antenna Type             :
     Serial Number            :
     Antenna Height (m)       : (m)
     Antenna Reference Point  : (ARP/BCR/BPA)
     Degree Offset from North :
     Antenna Radome Type      :
     Date Installed           : (dd-MMM-yyyy hh:mm UT)
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : (multiple lines)


5.   Local Site Ties

5.x  Monument Name            :
     Site Ref CDP Number      : (XXXX)
     Site Ref Domes Number    : (XXXXXXXXX)
     Differential Components from GPS Mark to Site Reference (ITRS)
       dx (m)                 : (m)
       dy (m)                 : (m)
       dz (m)                 : (m)
     Accuracy (mm)            : (mm)
     Date Measured            : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : (multiple lines)


6.   Frequency Standard

6.1  Standard Type            : INTERNAL
       Frequency              :
       Effective Dates        : dd-MMM-yyyy - dd-MMM-yyyy
       Notes                  : (multiple lines)

6.x  Standard Type            : (H-MASER/CESIUM/QUARTZ/INTERNAL/RUBIDIUM)
       Frequency              :
       Effective Dates        : (dd-MMM-yyyy - dd-MMM-yyyy)
       Notes                  : (multiple lines)


7.   Collocation Information

7.x  Instrumentation Type     : (DORIS/GLONASS/PRARE/SLR/VLBI)
       Status                 : (PERMANENT/MOBILE)
       Effective Dates        : (dd-MMM-yyyy - dd-MMM-yyyy)
       Notes                  : (multiple lines)


8.   Meteorological Instrumentation

8.1  Humidity Sensor Model    :
       Manufacturer           :
       Data Frequency         :
       Accuracy (% rel h)     : (% rel h)
       Effective Dates        : (dd-MMM-yyyy - dd-MMM-yyyy)
       Notes                  : (multiple lines)

8.2  Pressure Sensor Model    :
       Manufacturer           :
       Data Frequency         :
       Accuracy (mbar)        : (mbar)
       Height Diff to GPS (m) : (m)
       Effective Dates        : (dd-MMM-yyyy - dd-MMM-yyyy)
       Notes                  : (multiple lines)

8.3  Temperature Sensor Model :
       Manufacturer           :
       Data Frequency         :
       Accuracy (deg C)       : (deg C)
       Effective Dates        : (dd-MMM-yyyy - dd-MMM-yyyy)
       Notes                  : (multiple lines)

8.4  Water Vapor Radiometer   :
       Manufacturer           :
       Distance to GPS (m)    : (m)
       Elev Diff to GPS (m)   : (m)
       Effective Dates        : (dd-MMM-yyyy - dd-MMM-yyyy)
       Notes                  : (multiple lines)

8.5  Other Instrumentation    : (multiple lines)


9.   On-Site, Point of Contact Agency Information

     Agency                   : U.S. Geological Survey
                              : Office of Earthquakes, Volcanoes and
                              : Engineering
     Mailing Address          : U.S. Geological Survey
                              : 525 South Wilson Ave.
                              : Pasadena, CA 91106
     Primary Contact
       Contact Name           : Kenneth W. Hudnut
       Telephone (primary)    : (818) 583-7232
       Telephone (secondary)  :
       Fax                    : (818) 583-7827
       E-mail                 : hudnut@seismo.gps.caltech.edu
     Secondary Contact
       Contact Name           :
       Telephone (primary)    :
       Telephone (secondary)  :
       Fax                    :
       E-mail                 :
     Additional Information   : (multiple lines)


10.  Responsible Agency (if different from 9.)

     Agency                   : (multiple lines)
     Mailing Address          : (multiple lines)
                              :
                              :
     Primary Contact
       Contact Name           :
       Telephone (primary)    :
       Telephone (secondary)  :
       Fax                    :
       E-mail                 :
     Secondary Contact
       Contact Name           :
       Telephone (primary)    :
       Telephone (secondary)  :
       Fax                    :
       E-mail                 :
     Additional Information   : (multiple lines)


11.  More Information

     URL for More Information :
     Hardcopy on File
       Site Map               : (Y)
       Site Diagram           : (Y)
       Horizon Mask           : (Y)
       Monument Description   : (Y)
       Site Pictures          : (Y)
     Additional Information   : (multiple lines)
     Antenna Graphics with Dimensions


        ASHTECH: Metal Choke Ring Type

        NOTE: Dimensions and Offsets Presumed to be the same as for the TurboRogue DM-T
               (tests pending)

                         -----
                     /     +     \                        <-- 0.128  L2
                    |      +      |                       <-- 0.110  L1
  +--------------------------------------------------+    <-- 0.102  TCR
  |                                                  |
  |                                                  |
  |                                                  |
  |                                                  |
+-+--------------------------------------------------+-+  <-- 0.038
+-------------------+-------------+--------------------+  <-- 0.035  BCR
                    |             |
                   =|             |
                    +------x------+                       <-- 0.000  ARP

<--                      0.381                       -->
(                                                 NOTE: -0.040 m ARP to vert. datum mark)


   ARP: Antenna Reference Point
   L1 : L1 Phase Center                   L2 : L2 Phase Center
   TCR: Top of Chokering                  BCR: Bottom of Chokering