USN700USA Site Information Form (site log) International GNSS Service See Instructions at: https://files.igs.org/pub/station/general/sitelog_instr.txt 0. Form Prepared by (full name) : Tatevik Shakhbandaryan Date Prepared : 2022-04-27 Report Type : Update If Update: Previous Site Log : usn7_20220307.log Modified/Added Sections : 11 1. Site Identification of the GNSS Monument Site Name : U.S. Naval Observatory Time Service Four Character ID : USN7 Monument Inscription : NONE IERS DOMES Number : 40451S009 CDP Number : NONE Monument Description : TRIANGULATED AL STRUTS Height of the Monument : 7 m Monument Foundation : ROOF Foundation Depth : Marker Description : MOUNTING BRACKET HOLE, ARP Date Installed : 2014-11-12T00:00Z Geologic Characteristic : on aluminum structure on roof of of 2-story Bedrock Type : Bedrock Condition : Fracture Spacing : Fault zones nearby : Distance/activity : Additional Information : 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). : USN7 functionally replaces USN3. : The antenna mount was extended by 1.5m on : 2014-11-12 2. Site Location Information City or Town : Washington State or Province : D.C. Country : United States of America (the) Tectonic Plate : NORTH AMERICAN Approximate Position (ITRF) X coordinate (m) : 1112162.138 Y coordinate (m) : -4842854.667 Z coordinate (m) : 3985497.066 Latitude (N is +) : +385514.03801 Longitude (E is +) : -0770358.59575 Elevation (m,ellips.) : 58.924 Additional Information : 3. GNSS Receiver Information 3.1 Receiver Type : ASHTECH Z-XII3T Satellite System : GPS Serial Number : RT920012203 Firmware Version : IL01-1D04-MCF-12MX Elevation Cutoff Setting : 4 deg Date Installed : 2004-06-28T00:00Z Date Removed : 2018-08-28T00:00Z Temperature Stabiliz. : none Additional Information : 3.2 Receiver Type : SEPT POLARX5TR Satellite System : GPS+GLO+GAL+BDS Serial Number : 3013939 Firmware Version : 5.1.2 Elevation Cutoff Setting : 0 deg Date Installed : 2018-08-28T00:00Z Date Removed : 2019-07-17T17:00Z Temperature Stabiliz. : Additional Information : 3.3 Receiver Type : SEPT POLARX5TR Satellite System : GPS+GLO+GAL+BDS Serial Number : 3013939 Firmware Version : 0.0.0-181002 Elevation Cutoff Setting : 0 deg Date Installed : 2019-07-17T17:00Z Date Removed : 2020-01-10T22:35Z Temperature Stabiliz. : Additional Information : 3.4 Receiver Type : SEPT POLARX5TR Satellite System : GPS+GLO+GAL+BDS Serial Number : 3013939 Firmware Version : 5.3.0 Elevation Cutoff Setting : 0 deg Date Installed : 2020-01-10T22:35Z Date Removed : 2020-02-24T18:24Z Temperature Stabiliz. : Additional Information : 3.5 Receiver Type : SEPT POLARX5TR Satellite System : GPS+GLO+GAL+BDS Serial Number : 3013939 Firmware Version : 5.3.2 Elevation Cutoff Setting : 0 deg Date Installed : 2020-02-24T18:24Z Date Removed : 2021-02-04T00:22Z Temperature Stabiliz. : Additional Information : 3.6 Receiver Type : SEPT POLARX5TR Satellite System : GPS+GLO+GAL+BDS Serial Number : 3013939 Firmware Version : 5.4.0 Elevation Cutoff Setting : 0 deg Date Installed : 2021-02-04T00:22Z Date Removed : CCYY-MM-DDThh:mmZ Temperature Stabiliz. : 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 : TPSCR.G5 TPSH Serial Number : 762-11615 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 deg Antenna Radome Type : TPSH Radome Serial Number : Antenna Cable Type : Andrew FSJ1-50A (35422-33 phase stabilized) Antenna Cable Length : 39 m Date Installed : 2014-11-12T11:00Z Date Removed : CCYY-MM-DDThh:mmZ Additional Information : Antenna is a Multi-band GNSS unit with TOPCON : radome. : Antenna cable 14-April-2009 to present - Andrew : FSJ1-50A (35422-33 phase stabilized) 1/4 inch : Superflexible Foam Dielectric Heliax : Specifications: : Physical length 130 feet (39 m), mostly run in : ceiling and floor of USNO Bldg 78 : 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 : Antenna splitter - USNO specially designed : antenna splitter that has > 100 db port to port : isolation and flat group delay response at L1 : and L2. New 8-port splitter installed : 2014-11-12. : Antenna splitter cable - from splitter to : receiver. The Antenna splitter cable is : attached to a DC block and 20db PAD at the : receiver input to improve impedance matching. : A lightning arrestor was introduced in-line : 2014-11-12. : The measured delays through each component of : the system are summarized in the table below. : (Please view with a fixed-width font such as : Courier) : USN7 Station Calibration Computed 2018-10-17 : Antenna and cable delays : ------- : All delays listed in nanoseconds in L1/L2/L5 : TOPCON CR/G5 L1 L2 : L5 : Passive Element: 1.207 / : 1.664 / 1.889 : Active Element and Choke Ring: 17.430 / : 13.940 / 18.260 : Cables L1 L2 : L5 : Antenna to Lightning Suppressor: 7.390 / : 7.390 / 7.390 : LS to RF Splitter: 150.100 / : 150.100 / 150.100 : RF Splitter to Rx: 12.510 / : 12.460 / 12.470 : Other equipment L1 L2 : L5 : Lightning Suppressor: 0.470 / : 0.500 / 0.510 : RF Splitter: 8.100 / : 8.220 / 8.260 : GNSS Receiver Delays: : Septentrio PolaRx5 TR S/N 4701173 : All delays in format: : Signal (RINEX3 Code): Value in nanoseconds : GPS : L1 C/A (C1C): 9.691 ns : L1 P(Y) (C1W): 9.615 ns : L2 C (C2L): 8.618 ns : L2 P(Y) (C2W): 8.413 ns : L5 Q (C5Q): 10.206 ns : GALILEO : E1 (C1C): 10.287 ns : E5 a (C5Q): 10.198 ns : E5 b (C7Q): 7.174 ns : E5 AltBOC (C8Q): 8.508 ns : BeiDou : B1 (C2I): 2.781 ns : B2 (C7I): 6.980 ns 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.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 : 5 MHz Effective Dates : 1998-03-24/2018-08-28 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 : All calibration delays have already been : accounted for in the RAW pseudorange data : produced by USN3. 6.2 Standard Type : EXTERNAL H-MASER Input Frequency : 10 MHz Effective Dates : 2018-08-28/2020-06-09 Notes : Clock drift detected starting 2020-06-05. 6.3 Standard Type : INTERNAL Input Frequency : Effective Dates : 2020-06-09/2020-06-10 Notes : 6.4 Standard Type : EXTERNAL H-MASER Input Frequency : 10 MHz Effective Dates : 2020-06-10/CCYY-MM-DD Notes : 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.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 10.1 Date : 2014-09-10/2014-09-10 Event : Transitioned from .soc to .ash data types. For : soc data types used soc2rnx to do the : conversion to RINEX data. For ash data types : using teqc directly to do the conversion to : RINEX. : Also applying clock calibration to .ash derived : RINEX data. 10.2 Date : 2014-11-12/2014-11-12 Event : Antenna mount extended, Antenna type/dome : changed. New signal splitter (8-port) and : lightning arrester introduced in signal path. 10.3 Date : 2018-08-28/2022-01-27 Event : While we are evaluating the absolute calibration : values please note USN7 data starting from : 2018-08-28 has no calibration being applied to : RINEX data. : When new calibration values become available : RINEX data starting from 2018-08-28 will also : be reprocessed and resubmitted. 10.4 Date : 2022-02-10/CCYY-MM-DD Event : USN7 receiver has been re-calibrated. : RINEX data continues to have no calibration values being applied. 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 : USNO Telephone (primary) : Telephone (secondary) : Fax : E-mail : ggnops@jpl.nasa.gov Secondary Contact Contact Name : USNO Telephone (primary) : Telephone (secondary) : Fax : E-mail : ggnops@jpl.nasa.gov Additional Information : Regional Data Center - JPL : ggnops@jpl.nasa.gov 12. Responsible Agency (if different from 11.) Agency : (same as above in 11.) 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 : JPL Secondary Data Center : CDDIS 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 (insert text graphic from file antenna.gra)