[IGSMAIL-1868] new AMCT site at Falcon Air Force Base

Jim Jim
Mon Apr 20 12:49:17 PDT 1998


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IGS Electronic Mail      Mon Apr 20 12:49:17 PDT 1998      Message Number 1868
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Author: Jim Ray
Subject: new AMCT site at Falcon Air Force Base

A new GPS tracking site has been installed at the Falcon Air Force Base,
near Colorado Springs, CO, USA, on the rooftop of Building 400.  The
geodetic reference point is the ARP rather than a conventional
monument.  Falcon AFB is the home of the GPS Operations Control Segment.

The new station is named `AMCT' to indicate that its frequency standard
is a 5 MHz signal from the steered H-maser which serves as the USNO
Alternate Master Clock.  AMC is kept closely aligned to UTC(USNO) via
regular two-way satellite time transfer measurements.  We intend to
calibrate the clock offset from the H-maser to the GPS antenna in order
to provide a direct link to the AMC time.

The current antenna installation is not permanent because the mount is
not sufficiently stable.  However, data from the current installation is
being disseminated to support data analysis and comparison efforts related
to the IGS/BIPM timing project.  The antenna will be moved when a more
stable mount is installed.

The NOAA GODC group has kindly assisted with the installation of this
GPS receiver and will serve as the Regional Data Center for data
distribution.  We are, once again, very appreciative of the support that
the NOAA group has provided.

AMCT data will soon be available at CDDIS starting 25 March 1998.  A copy
of the Site Information Form is attached below.

Jim Ray
U.S. Naval Observatory

-----------------------------------------------------------------------------

     AMCT Site Information Form
     International GPS Service for Geodynamics


0.   Form

     Prepared by (full name)  : Bill Bollwerk, Jim Ray (USNO)
     Date Prepared            : 20-APR-1998
     Report Type              : NEW
     Prepared Using           :


1.   Site Identification of the GPS Monument

     Site Name                : Alternate Master Clock (timing test)
     Four Character ID        : AMCT
     Monument Inscription     : no monument, GPS antenna ARP
     IERS DOMES Number        : 40472S003
     CDP Number               : none
     Date Installed           : 24-MAR-1998
     Geologic Characteristic  : on roof of 5-story building
       Bedrock Type           : 
       Bedrock Condition      : 
       Fracture Spacing       : 
       Notes                  : 
     Additional Information   : The antenna is mounted on top of the roof
                                (flat) of Building 400 (5 stories) at Falcon
                                Air Force Base, outside of Colorado Springs,
                                Colorado.  There are no nearby geodetic markers
                                or control points.


2.   Site Location Information

     City or Town             : Falcon Air Force Base, Colorado Springs
     State or Province        : Colorado
     Country                  : U.S.A.
     Tectonic Plate           : North American
     Approximate Position
       X coordinate (m)       : -1248596.241
       Y coordinate (m)       : -4819429.589
       Z coordinate (m)       :  3976506.987
       Latitude (deg)         :  38.803114 N
       Longitude (deg)        : 255.475405 E
       Elevation (m)          : 1911.087
     Additional Information   : (multiple lines)


3.   GPS Receiver Information

3.1  Receiver Type            : TURBOROGUE SNR12
     Serial Number            : T247
     Firmware Version         : 3.2.32.1
     Date Installed           : 24-MAR-1998
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : (multiple lines)

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             : DORNE MARGOLIN T
     Serial Number            : 308
     Antenna Height (m)       : 0.0
     Antenna Reference Point  : ARP
     Degree Offset from North : oriented North but not measured
     Antenna Radome Type      : none
     Date Installed           : 24-MAR-1998
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : This antenna is located 28.5 inches nearly
                                directly north of the antenna for a TTR-4P
                                timing receiver.  NIMA surveyed the TTR-4P
                                antenna location in August 1996 with the
                                following results:
                                 38 Degrees 48' 11.1860" N  ( 38.803107222 N)
                                104 Degrees 31' 28.5435" W  (255.475404583 E)
                                1911.087 m Ellipsoid Height
                                with a stated accuracy of +/- 30 cm (1 sigma)
                                in each component.  The TurboRogue antenna
                                is mounted at the same height level on the
                                same T-bar as the TTR-4P 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

5.1  Monument Name            : none
     Site Ref CDP Number      : none
     Site Ref Domes Number    : none
     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)

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            : steered H-MASER
       Frequency              : 5 MHz
       Effective Dates        : 24-MAR-1998                
       Notes                  : reference signal from USNO Alternate Master
                                Clock #1, the back-up realization of UTC(USNO)
                                via two-way satellite time transfer;
                                calibration of clock offset to be established
                                later

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

7.1  Instrumentation Type     : none
       Status                 : 
       Effective Dates        : 
       Notes                  : 

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)     : 
       Effective Dates        : (dd-MMM-yyyy - dd-MMM-yyyy)
       Notes                  : (multiple lines)

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

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

8.4  Water Vapor Radiometer   : none
       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    : The USNO Alternate Master Clock is located in
                                the same building as this GPS receiver.  The
                                differential time offset between the Alternate
                                Master Clock and the GPS antenna will be
                                monitored and may be used to calibrate the
                                receiver clock time directly to UTC(AMC).


9.   On-Site, Point of Contact Agency Information

     Agency                   : U.S. Naval Observatory, Alternate Master Clock
     Mailing Address          : USNO/AMC
                              : 400 O'Malley Ave, Suite 44
                              : Falcon AFB, CO 80912-4044
     Primary Contact          
       Contact Name           : Bill Bollwerk
       Telephone (primary)    : 719-567-6740
       Telephone (secondary)  : 719-567-6763
       Fax                    :
       E-mail                 : bill at tycho.usnogps.navy.mil
     Secondary Contact          
       Contact Name           : Paul Wheeler (USNO)
       Telephone (primary)    : 202-762-1581
       Telephone (secondary)  :
       Fax                    : 
       E-mail                 : paul at tsee2.usno.navy.mil
     Additional Information   : Regional Data Center is NOAA GODC
     Regional Data Center Contact          
       Contact Name           : Linda Nussear (NOAA)
       Telephone (primary)    : 301-713-2852
       Telephone (secondary)  :
       Fax                    : 301-713-4475
       E-mail                 : linda at gracie.grdl.noaa.gov


10.  Responsible Agency (if different from 9.)

     Agency                   : (same as above in 9.)
     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               : N
       Site Diagram           : N
       Horizon Mask           : N
       Monument Description   : no monument
       Site Pictures          : N
     Additional Information   : (multiple lines)
     Antenna Graphics with Dimensions



             TurboRogue: DORNE MARGOLIN T

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

<--                      0.381                       -->


   ARP: Antenna Reference Point
   L1 : L1 Phase Center                   L2 : L2 Phase Center
   TCR: Top of Chokering                  BCR: Bottom of Chokering
   TGP: Top of Ground Plane               BGP: Bottom of Ground Plane
   TPA: Top of Preamplifier               BPA: Bottom of Preamplifier
   TOP: Top of Pole



[Mailed From: Jim Ray (USNO 202-762-1444) <jimr at Maia.usno.navy.mil>]



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