Subject: [IGSMAIL-1598] USNO Site
From: Dennis McCarthy
Date: Tue, 13 May 1997 8:35:36 PDT

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IGS Electronic Mail      Tue May 13  8:35:36 PDT 1997      Message Number 1598
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Author: Dennis McCarthy
Subject: USNO Site

A new permanent GPS tracking site has been installed at the U.S. Naval
Observatory.  The new station is named `USNO' and it is mounted on the
rooftop of Building 52 at the Observatory, located near downtown
Washington, DC.  The geodetic reference point is the ARP rather than
a conventional monument.

This receiver uses a reference 5 MHz signal from the steered H-maser 
which serves as the realization of the UTC(USNO) timescale.  We intend
to calibrate the clock offset from the H-maser to the GPS antenna in
order to provide a direct link between UTC(USNO) and the time standards
at the tracking stations of the IGS global network as well as the GPS
satellites themselves.

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.

USNO data are available at CDDIS starting 01 May 1997.  A copy of the Site
Information Form is attached below.

Dennis McCarthy
Director of Time, U.S. Naval Observatory

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

     USNO Site Information Form
     International GPS Service for Geodynamics

0.   Form

     Prepared by (full name)  : Linda Nussear (NOAA), Jim Ray (USNO)
     Date Prepared            : 12-MAY-1997
     Report Type              : NEW
     Prepared Using           :

1.   Site Identification of the GPS Monument

     Site Name                : U.S. Naval Observatory
     Four Character ID        : USNO
     Monument Inscription     : no monument, ARP
     IERS DOMES Number        : 40451S003 
     CDP Number               : none
     Date Installed           : 24-APR-1997
     Geologic Characteristic  : on edge of roof of 3-story building
       Bedrock Type           : 
       Bedrock Condition      : 
       Fracture Spacing       : 
       Notes                  : 
     Additional Information   : The antenna is mounted near the edge of the
                                roof (flat) of Building 52 (3 stories) at
                                the U.S. Naval Observatory inside Washington,
                                DC.  There are no nearby geodetic markers or
                                control points.

2.   Site Location Information

     City or Town             : Washington
     State or Province        : District of Columbia (DC)
     Country                  : U.S.A.
     Tectonic Plate           : North American
     Approximate Position
       X coordinate (m)       :  1112189.117
       Y coordinate (m)       : -4842954.301
       Z coordinate (m)       :  3985351.389
       Latitude (deg)         :  38.9190 N
       Longitude (deg)        : 282.9338 E
       Elevation (m)          :  47.654
     Additional Information   : (multiple lines)

3.   GPS Receiver Information

3.1  Receiver Type            : TurboRogue SNR12
     Serial Number            : T246
     Firmware Version         : 3.32.1.4
     Date Installed           : 24-APR-1997
     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            : 309
     Antenna Height (m)       : (m)
     Antenna Reference Point  : ARP
     Degree Offset from North : oriented North but not measured
     Antenna Radome Type      : none
     Date Installed           : 24-APR-1997
     Date Removed             : (dd-MMM-yyyy hh:mm UT)
     Additional Information   : (multiple lines)

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-APR-1997                
       Notes                  : reference signal from USNO Master Clock,
                                the realization of UTC(USNO); 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    : Lithium chloride dew point units
       Manufacturer           : Honeywell probes/General Eastern units
       Data Frequency         : 10 sec
       Accuracy (% rel h)     : dew point to 5 deg F
       Effective Dates        : (dd-MMM-yyyy - dd-MMM-yyyy)
       Notes                  : probes are treated with lithium chloride
                                activated solution and dried

8.2  Pressure Sensor Model    : Digital barometer (model 361)
       Manufacturer           : Setra
       Data Frequency         : 10 sec
       Accuracy (mbar)        : 0.1 mm mercury
       Height Diff to GPS (m) : unknown
       Effective Dates        : (dd-MMM-yyyy - dd-MMM-yyyy)
       Notes                  : all met sensors are located at USNO in
                                Building 7 (the Transit House for 6-inch
                                transit circle); air temp, air pressure, and
                                dew point read every 10 seconds; contact for
                                met data is Theodore J. Rafferty, Astrometry
                                Dept., USNO ([email-masked])

8.3  Temperature Sensor Model : Platium Res Probes (model CT-807-A)
       Manufacturer           : Hy-cal
       Data Frequency         : 10 sec
       Accuracy (deg C)       : (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 Master Clock is located in the
                                same building as this GPS receiver.  The
                                differential time offset between the Master
                                Clock and the GPS antenna will be monitored
                                and used to calibrate the receiver clock time
                                directly to UTC(USNO).

9.   On-Site, Point of Contact Agency Information

     Agency                   : U.S. Naval Observatory
     Mailing Address          : TS Dept.
                              : 3450 Massachusetts Ave., NW
                              : Washington, DC  20392-5420
     Primary Contact          
       Contact Name           : Paul Wheeler (USNO)
       Telephone (primary)    : 202-762-1581  
       Telephone (secondary)  : 
       Fax                    :
       E-mail                 : [email-masked]
     Secondary Contact          
       Contact Name           : Jim Ray (USNO)
       Telephone (primary)    : 202-762-1444
       Telephone (secondary)  :
       Fax                    : 202-762-1563
       E-mail                 : [email-masked]
     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                 : [email-masked]

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
--
Dennis D. McCarthy                       [email-masked]
Director, Directorate of Time            phone: (202) 762-1837
U.S. Naval Observatory                   fax: (202) 762-1563
Washington, DC 20392-5420

[Mailed From: Dennis McCarthy <[email-masked]>]