USN4 Site Information Form (site log) International GNSS Service See Instructions at: ftp://igscb.jpl.nasa.gov/pub/station/general/sitelog_instr.txt 0. Form Prepared by (full name) : Stephen Mitchell Date Prepared : 2013-05-01 Report Type : UPDATE If Update: Previous Site Log : usn4_20120508.log Modified/Added Sections : 3.1 added satellite systems : 3.2 updated firmware version 1. Site Identification of the GNSS Monument Site Name : U.S. Naval Observatory Time Service Four Character ID : USN4 Monument Inscription : IERS DOMES Number : 40451S007 CDP Number : Monument Description : TRIANGULATED AL STRUTS Height of the Monument : 5 m Monument Foundation : ROOF Foundation Depth : Marker Description : MOUNTING BRACKET HOLE, ARP Date Installed : 2004-06-28T00:00Z Geologic Characteristic : on aluminum structure on roof of of 2-story Bedrock Type : Bedrock Condition : Fracture Spacing : Fault zones nearby : Distance/activity : Additional Information : Same DOMES number as USN3 since same antenna : The antenna is mounted on a baseball diamond : shaped aluminum structure mounted on the roof : (2 stories) of the Time Service department : building at the U.S. Naval Observatory, : Washington. D.C.. There are nearby geodetic : markers, but this antenna has not been surveyed : to those markers. (see accompanying pictures). : USN3 functionally replaces USN1. 2. Site Location Information City or Town : Washington State or Province : D.C. Country : United States Tectonic Plate : NORTH AMERICAN Approximate Position (ITRF) X coordinate (m) : 1112162.140 Y coordinate (m) : -4842853.628 Z coordinate (m) : 3985496.084 Latitude (N is +) : +385514.033 Longitude (E is +) : -0770358.586 Elevation (m,ellips.) : 57.519 Additional Information : 3. GNSS Receiver Information 3.1 Receiver Type : SEPT POLARX4TR Satellite System : GPS+GLO+GAL+SBAS Serial Number : SN11203000923 Firmware Version : 2.3 Elevation Cutoff Setting : 0 deg Date Installed : 2011-09-02T00:00Z Date Removed : 2013-05-01T14:00Z Temperature Stabiliz. : none Additional Information : 3.2 Receiver Type : SEPT POLARX4TR Satellite System : GPS+GLO+GAL+SBAS Serial Number : SN11203000923 Firmware Version : 2.3.4 Elevation Cutoff Setting : 0 deg Date Installed : 2013-05-01T14:00Z Date Removed : CCYY-MM-DDThh:mmZ Temperature Stabiliz. : none Additional Information : 3.x Receiver Type : (A20, from rcvr_ant.tab; see instructions) Satellite System : (GPS+GLO+GAL+BDS+QZSS+SBAS) Serial Number : (A20, but note the first A5 is used in SINEX) Firmware Version : (A11) Elevation Cutoff Setting : (deg) Date Installed : (CCYY-MM-DDThh:mmZ) Date Removed : (CCYY-MM-DDThh:mmZ) Temperature Stabiliz. : (none or tolerance in degrees C) Additional Information : (multiple lines) 4. GNSS Antenna Information 4.1 Antenna Type : AOAD/M_T NONE Serial Number : KW5-0258 Antenna Reference Point : BPA Marker->ARP Up Ecc. (m) : 0.0000 Marker->ARP North Ecc(m) : 0.0000 Marker->ARP East Ecc(m) : 0.0000 Alignment from True N : oriented North but not measured Antenna Radome Type : NONE Radome Serial Number : Antenna Cable Type : Andrew FSJ1-50A (35422-33 phase stabilized) Antenna Cable Length : 39 m Date Installed : 2004-06-28T16:00Z Date Removed : CCYY-MM-DDThh:mmZ Additional Information : This antenna is a standard AOAD/M_T using a : special LNA designed to have a flat group : delay response at both L1 and L2. Because : of this flat group delay response the thermal : sensitivity of this antenna should be much : improved over what is typically found in this : antenna type. : Antenna Group Delay at L1 = 24.13 NS : Antenna Group Delay at L2 = 25.93 NS : Antenna cable 14-April-2009 to present - : Andrew FSJ1-50A (35422-33 phase stabilized) : 1/4 inch Superflexible Foam Dielectric : Heliax -- physical length 130 feet : (39 m), mostly run in ceiling and : floor of USNO Bldg 78; : specifications - : Velocity factor 0.84 : DC resistance 2 to 3 ohms per 1000 foot : Capacitance, 24.2 pF/foot : Inductance, .061 uH/foot : Loss at 1250 MHz 6.77 dB/100 foot : Loss at 1500 MHz 7.47 dB/100 foot : Electrical Length Change versus Temperature - : 400 PPM over (-40 to 30 C) or 5.7 PPM/C : => 0.02 ps/m/C 4.x Antenna Type : (A20, from rcvr_ant.tab; see instructions) Serial Number : (A*, but note the first A5 is used in SINEX) Antenna Reference Point : (BPA/BCR/XXX from "antenna.gra"; see instr.) Marker->ARP Up Ecc. (m) : (F8.4) Marker->ARP North Ecc(m) : (F8.4) Marker->ARP East Ecc(m) : (F8.4) Alignment from True N : (deg; + is clockwise/east) Antenna Radome Type : (A4 from rcvr_ant.tab; see instructions) Radome Serial Number : Antenna Cable Type : (vendor & type number) Antenna Cable Length : (m) Date Installed : (CCYY-MM-DDThh:mmZ) Date Removed : (CCYY-MM-DDThh:mmZ) Additional Information : (multiple lines) 5. Surveyed Local Ties 5.1 Tied Marker Name : none Tied Marker Usage : Tied Marker CDP Number : none Tied Marker DOMES Number : Differential Components from GNSS Marker to the tied monument (ITRS) dx (m) : dy (m) : dz (m) : Accuracy (mm) : Survey method : Date Measured : CCYY-MM-DDThh:mmZ Additional Information : 5.x Tied Marker Name : Tied Marker Usage : (SLR/VLBI/LOCAL CONTROL/FOOTPRINT/etc) Tied Marker CDP Number : (A4) Tied Marker DOMES Number : (A9) Differential Components from GNSS Marker to the tied monument (ITRS) dx (m) : (m) dy (m) : (m) dz (m) : (m) Accuracy (mm) : (mm) Survey method : (GPS CAMPAIGN/TRILATERATION/TRIANGULATION/etc) Date Measured : (CCYY-MM-DDThh:mmZ) Additional Information : (multiple lines) 6. Frequency Standard 6.1 Standard Type : EXTERNAL H-MASER Input Frequency : 10 MHz Effective Dates : 1998-03-24/CCYY-MM-DD Notes : Reference signal from USNO Master clock (MC2), : the primary realization of UTC(USNO), located : in Bldg. 78 in a thermal chamber. MC2 is : steered to UTC using information obtained : from the Bureau International des Poids : et Mesures (BIPM) roughly each month. See : the BIPM Circular T for more detail, : http://www.bipm.fr/enus/5_Scientific/c_time/ : time_ftp.shtml 6.x Standard Type : (INTERNAL or EXTERNAL H-MASER/CESIUM/etc) Input Frequency : (if external) Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Notes : (multiple lines) 7. Collocation Information 7.1 Instrumentation Type : none Status : Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Notes : 7.x Instrumentation Type : (GPS/GLONASS/DORIS/PRARE/SLR/VLBI/TIME/etc) Status : (PERMANENT/MOBILE) Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Notes : (multiple lines) 8. Meteorological Instrumentation 8.1.1 Humidity Sensor Model : HUMICA H-sensor (pn 16663) Manufacturer : Vaisala Serial Number : Data Sampling Interval : 15 sec Accuracy (% rel h) : 1%(0...90%RH) Aspiration : NATURAL Height Diff to Ant : -0.724 m Calibration date : (CCYY-MM-DD) Effective Dates : 2001-08-21/CCYY-MM-DD Notes : NOAA GSOS # 062 8.1.x Humidity Sensor Model : Manufacturer : Serial Number : Data Sampling Interval : (sec) Accuracy (% rel h) : (% rel h) Aspiration : (UNASPIRATED/NATURAL/FAN/etc) Height Diff to Ant : (m) Calibration date : (CCYY-MM-DD) Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Notes : (multiple lines) 8.2.1 Pressure Sensor Model : PTB220 Manufacturer : Vaisala Serial Number : Data Sampling Interval : 15 sec Accuracy : 0.1 hPa Height Diff to Ant : -0.724 m Calibration date : (CCYY-MM-DD) Effective Dates : 2001-08-21/CCYY-MM-DD Notes : met sensors are located at USNO on rooftop : of Building 52A (~ few hundred m from GPS ant.) : NOAA GSOS # 062 8.2.x Pressure Sensor Model : Manufacturer : Serial Number : Data Sampling Interval : (sec) Accuracy : (hPa) Height Diff to Ant : (m) Calibration date : (CCYY-MM-DD) Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Notes : (multiple lines) 8.3.1 Temp. Sensor Model : PT100 RTD 1/s DIN 43760B Manufacturer : Vaisala Serial Number : Data Sampling Interval : 15 sec Accuracy : 0.1 @ 20.0 deg C Aspiration : NATURAL Height Diff to Ant : -0.724 m Calibration date : Effective Dates : 2001-08-21/CCYY-MM-DD Notes : NOAA GSOS # 062 8.3.x Temp. Sensor Model : Manufacturer : Serial Number : Data Sampling Interval : (sec) Accuracy : (deg C) Aspiration : (UNASPIRATED/NATURAL/FAN/etc) Height Diff to Ant : (m) Calibration date : (CCYY-MM-DD) Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Notes : (multiple lines) 8.4.x Water Vapor Radiometer : Manufacturer : Serial Number : Distance to Antenna : (m) Height Diff to Ant : (m) Calibration date : (CCYY-MM-DD) Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Notes : (multiple lines) 8.5.x Other Instrumentation : (multiple lines) 9. Local Ongoing Conditions Possibly Affecting Computed Position 9.1.x Radio Interferences : (TV/CELL PHONE ANTENNA/RADAR/etc) Observed Degradations : (SN RATIO/DATA GAPS/etc) Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Additional Information : (multiple lines) 9.2.x Multipath Sources : (METAL ROOF/DOME/VLBI ANTENNA/etc) Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Additional Information : (multiple lines) 9.3.x Signal Obstructions : (TREES/BUILDINGS/etc) Effective Dates : (CCYY-MM-DD/CCYY-MM-DD) Additional Information : (multiple lines) 10. Local Episodic Effects Possibly Affecting Data Quality 10.x Date : (CCYY-MM-DD/CCYY-MM-DD) Event : (TREE CLEARING/CONSTRUCTION/etc) 11. On-Site, Point of Contact Agency Information Agency : U.S. Naval Observatory Preferred Abbreviation : USNO Mailing Address : Time Service Department : 3450 Massachusetts Ave., NW : Washington, D.C. 20392-5420 Primary Contact Contact Name : Stephen Mitchell (USNO) Telephone (primary) : 202-762-0740 Telephone (secondary) : Fax : 202-762-1511 E-mail : stephen.mitchell@usno.navy.mil Secondary Contact Contact Name : Ed Powers Telephone (primary) : 202-762-1451 Telephone (secondary) : Fax : 202-762-1511 E-mail : edward.powers@usno.navy.mil Additional Information : 12. Responsible Agency (if different from 11.) Agency : Preferred Abbreviation : Mailing Address : Primary Contact Contact Name : Telephone (primary) : Telephone (secondary) : Fax : E-mail : Secondary Contact Contact Name : Telephone (primary) : Telephone (secondary) : Fax : E-mail : Additional Information : 13. More Information Primary Data Center : CDDIS Secondary Data Center : IGN 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 : 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=BPA <-- 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 All dimensions are in meters.