ALGO Site Information Form (site log) International GPS Service See Instructions at: ftp://igscb.jpl.nasa.gov/pub/station/general/sitelog_instr.txt 0. Form Prepared by (full name) : Stuart Elson Date Prepared : 2013-01-02 Report Type : UPDATE If Update: Previous Site Log : algo_20121221.log Modified/Added Sections : 4.5 1. Site Identification of the GNSS Monument Site Name : ALGO CACS-GSD Four Character ID : ALGO Monument Inscription : 883160 IERS DOMES Number : 40104M002 CDP Number : Monument Description : Concrete Pier Height of the Monument : 2.00 (m) Monument Foundation : Exposed bedrock Foundation Depth : 1.50 (m) Marker Description : Brass Plate Date Installed : 1991-01-19T00:00Z Geologic Characteristic : Bedrock Bedrock Type : IGNEOUS Bedrock Condition : WEATHERED Fracture Spacing : 10-50 cm Fault zones nearby : Distance/activity : Additional Information : The GNSS reference mark consists of a brass : plate with a forced centered stainless : steel bolt embedded on top of a 2.0 m : high concrete pier. The concrete pier is : anchored to exposed bedrock by steel : reinforcing rods. 2. Site Location Information City or Town : Algonquin Park State or Province : ON Country : Canada Tectonic Plate : North American Approximate Position (ITRF) X coordinate (m) : 918129.40 Y coordinate (m) : -4346071.20 Z coordinate (m) : 4561977.80 Latitude (N is +) : +455731.68 Longitude (E is +) : -0780417.04 Elevation (m,ellips.) : 202.00 Additional Information : ALGO is a continuously tracking GNSS station : and is part of the Canadian Active Control : System (CACS). The station is colocated : with the ALG2 GNSS station, the ALG3 GNSS : station and the VLBI reference mark in : Algonquin Park, Ontario. : The Alqonguin Space Complex in Algonquin Park : is located 160km west of Ottawa, Ontario. 3. GNSS Receiver Information 3.1 Receiver Type : ROGUE SNR-8 Satellite System : GPS Serial Number : R115 Firmware Version : MEENIX 7.? Elevation Cutoff Setting : 10 Date Installed : 1991-01-19T00:00Z Date Removed : 1993-02-08T00:00Z Temperature Stabiliz. : Additional Information : 3.2 Receiver Type : ROGUE SNR-8 Satellite System : GPS Serial Number : R115 Firmware Version : MEENIX 7.3 Elevation Cutoff Setting : 10 Date Installed : 1993-02-09T00:00Z Date Removed : 1994-01-12T00:00Z Temperature Stabiliz. : Additional Information : 3.3 Receiver Type : ROGUE SNR-8 Satellite System : GPS Serial Number : R115 Firmware Version : MEENIX 7.5 Elevation Cutoff Setting : 10 Date Installed : 1994-01-12T00:00Z Date Removed : 1994-02-16T17:36Z Temperature Stabiliz. : Additional Information : 3.4 Receiver Type : ROGUE SNR-8000 Satellite System : GPS Serial Number : T226 Firmware Version : TURBO 2.8.32.1 Elevation Cutoff Setting : 10 Date Installed : 1994-02-16T19:13Z Date Removed : 1994-07-26T23:50Z Temperature Stabiliz. : Additional Information : 3.5 Receiver Type : ROGUE SNR-8000 Satellite System : GPS Serial Number : T230 Firmware Version : TURBO 2.8.32.1 Elevation Cutoff Setting : 10 Date Installed : 1994-07-27T00:00Z Date Removed : 1994-12-20T23:55Z Temperature Stabiliz. : Additional Information : 3.6 Receiver Type : ROGUE SNR-8000 Satellite System : GPS Serial Number : T226 Firmware Version : TURBO 3.0.32.2 Elevation Cutoff Setting : 10 Date Installed : 1994-12-21T00:00Z Date Removed : 1995-10-06T21:30Z Temperature Stabiliz. : Additional Information : 3.7 Receiver Type : ROGUE SNR-8000 Satellite System : GPS Serial Number : T226 Firmware Version : TURBO 3.2.32.1 Elevation Cutoff Setting : 10 Date Installed : 1995-10-06T21:30Z Date Removed : 1996-12-19T00:00Z Temperature Stabiliz. : Additional Information : 3.8 Receiver Type : ROGUE SNR-8000 Satellite System : GPS Serial Number : T305 Firmware Version : TURBO 3.2.32.5X Elevation Cutoff Setting : 10 Date Installed : 1996-12-19T00:00Z Date Removed : 1997-05-16T21:00Z Temperature Stabiliz. : Additional Information : 3.9 Receiver Type : ROGUE SNR-8000 Satellite System : GPS Serial Number : T305 Firmware Version : VERS.97/03 3.2.32.5X Elevation Cutoff Setting : 10 Date Installed : 1997-05-16T21:00Z Date Removed : 1997-06-11T23:50Z Temperature Stabiliz. : Additional Information : 3.10 Receiver Type : ROGUE SNR-8000 Satellite System : GPS Serial Number : T164 Firmware Version : VERS.97/03 3.2.32.5X Elevation Cutoff Setting : 10 Date Installed : 1997-06-12T00:00Z Date Removed : 1997-08-26T16:45Z Temperature Stabiliz. : Additional Information : 3.11 Receiver Type : ROGUE SNR-8000 Satellite System : GPS Serial Number : T302 Firmware Version : VERS.97/03 3.2.32.5X Elevation Cutoff Setting : 10 Date Installed : 1997-08-26T16:45Z Date Removed : 1997-11-02T13:30Z Temperature Stabiliz. : Additional Information : 3.12 Receiver Type : ROGUE SNR-8000 Satellite System : GPS Serial Number : T164 Firmware Version : VERS.97/03 3.2.32.5X Elevation Cutoff Setting : 10 Date Installed : 1997-11-02T13:30Z Date Removed : 1999-08-18T23:59Z Temperature Stabiliz. : Additional Information : 3.13 Receiver Type : AOA BENCHMARK ACT Satellite System : GPS Serial Number : 1103 Firmware Version : 3.3.32.2N Elevation Cutoff Setting : 10 Date Installed : 1999-08-19T00:00Z Date Removed : 2007-10-12T17:15Z Temperature Stabiliz. : Additional Information : 3.14 Receiver Type : AOA BENCHMARK ACT Satellite System : GPS Serial Number : 2048 Firmware Version : 3.3.32.2N Elevation Cutoff Setting : 10 Date Installed : 2007-10-12T17:15Z Date Removed : 2008-12-12T16:54Z Temperature Stabiliz. : Additional Information : 3.15 Receiver Type : AOA BENCHMARK ACT Satellite System : GPS Serial Number : 124-U Firmware Version : 3.3.32.2N Elevation Cutoff Setting : 10 Date Installed : 2008-12-18T18:44Z Date Removed : 2012-12-20T17:00Z Temperature Stabiliz. : Additional Information : 3.16 Receiver Type : TPS NET-G3A Satellite System : GPS+GLO Serial Number : 618-01882 Firmware Version : 3.5p2 Elevation Cutoff Setting : 5 Date Installed : 2012-12-20T17:00Z 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 : Date Installed : (CCYY-MM-DDThh:mmZ) Date Removed : (CCYY-MM-DDThh:mmZ) Temperature Stabiliz. : (none or tolerance in degrees C) Additional Information : 4. GNSS Antenna Information 4.1 Antenna Type : AOAD/M_B NONE Serial Number : 111 Antenna Reference Point : BCR Marker->ARP Up Ecc. (m) : 000.1140 Marker->ARP North Ecc(m) : 000.0000 Marker->ARP East Ecc(m) : 000.0000 Alignment from True N : 0.0 Antenna Radome Type : NONE Radome Serial Number : Antenna Cable Type : Antenna Cable Length : 0.00 (m) Date Installed : 1991-01-19T00:00Z Date Removed : 1994-02-16T17:36Z Additional Information : 4.2 Antenna Type : AOAD/M_T NONE Serial Number : 173 Antenna Reference Point : BPA Marker->ARP Up Ecc. (m) : 000.0000 Marker->ARP North Ecc(m) : 000.0000 Marker->ARP East Ecc(m) : 000.0000 Alignment from True N : 0.0 Antenna Radome Type : NONE Radome Serial Number : Antenna Cable Type : Antenna Cable Length : 0.00 (m) Date Installed : 1994-02-16T19:13Z Date Removed : 1994-05-18T23:38Z Additional Information : 4.3 Antenna Type : AOAD/M_T NONE Serial Number : 173 Antenna Reference Point : BPA Marker->ARP Up Ecc. (m) : 000.1000 Marker->ARP North Ecc(m) : 000.0000 Marker->ARP East Ecc(m) : 000.0000 Alignment from True N : 0.0 Antenna Radome Type : NONE Radome Serial Number : Antenna Cable Type : Antenna Cable Length : 0.00 (m) Date Installed : 1994-05-19T00:00Z Date Removed : 1997-01-16T00:00Z Additional Information : 4.4 Antenna Type : AOAD/M_T NONE Serial Number : 386 Antenna Reference Point : BPA Marker->ARP Up Ecc. (m) : 000.1000 Marker->ARP North Ecc(m) : 000.0000 Marker->ARP East Ecc(m) : 000.0000 Alignment from True N : 0.0 Antenna Radome Type : NONE Radome Serial Number : Antenna Cable Type : LDF4-50A HELIAX Antenna Cable Length : 100.00 (m) Date Installed : 1997-01-16T00:00Z Date Removed : 2012-12-20T17:00Z Additional Information : 4.5 Antenna Type : AOAD/M_T NONE Serial Number : 303 Antenna Reference Point : BPA Marker->ARP Up Ecc. (m) : 000.1000 Marker->ARP North Ecc(m) : 000.0000 Marker->ARP East Ecc(m) : 000.0000 Alignment from True N : 0.0 Antenna Radome Type : NONE Radome Serial Number : Antenna Cable Type : LDF4-50A HELIAX Antenna Cable Length : 100.00 (m) Date Installed : 2012-12-20T17:00Z Date Removed : (CCYY-MM-DDThh:mmZ) Additional Information : Upgraded LNA accepts GNSS spectrum 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 : 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 : 5. Surveyed Local Ties 5.1 Tied Marker Name : 683100 Tied Marker Usage : Tied Marker CDP Number : 7282 Tied Marker DOMES Number : 40104S001 Differential Components from GNSS Marker to the tied monument (ITRS) dx (m) : -94.756 dy (m) : -61.021 dz (m) : -6.665 Accuracy (mm) : 0.0 Survey method : Date Measured : 1993-08-03T00:00Z Additional Information : Differential coordinates are from the GPS : monument to the reference and other monuments. : The components are parallel to the XYZ-Axes of : the Global Geocentric Reference System ITRF : (WGS-84). 5.2 Tied Marker Name : 933000 Tied Marker Usage : Tied Marker CDP Number : 7410 Tied Marker DOMES Number : Differential Components from GNSS Marker to the tied monument (ITRS) dx (m) : 83.51 dy (m) : 4.669 dz (m) : -20.142 Accuracy (mm) : 0.0 Survey method : Date Measured : 1994-05-03T00:00Z 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) : dy (m) : dz (m) : Accuracy (mm) : Survey method : (GPS CAMPAIGN/TRILATERATION/TRIANGULATION/etc) Date Measured : (CCYY-MM-DDThh:mmZ) Additional Information : 6. Frequency Standard 6.1 Standard Type : H-MASER Input Frequency : 5 MHZ Effective Dates : 1991-04-01/2001-03-20 Notes : 6.2 Standard Type : H-MASER Input Frequency : 5 MHZ Effective Dates : 2001-03-20/2001-03-26 Notes : 6.3 Standard Type : H-MASER Input Frequency : 5 MHZ Effective Dates : 2001-03-26/2002-07-13 Notes : 6.4 Standard Type : INTERNAL Input Frequency : Effective Dates : 2002-07-13/2002-07-15 Notes : 6.5 Standard Type : H-MASER Input Frequency : 5 MHZ Effective Dates : 2002-07-15/2003-01-17 Notes : 6.6 Standard Type : INTERNAL Input Frequency : Effective Dates : 2003-01-18/2003-01-22 Notes : 6.7 Standard Type : H-MASER Input Frequency : 5 MHZ Effective Dates : 2003-01-22/2003-01-23 Notes : 6.8 Standard Type : H-MASER Input Frequency : 5 MHZ Effective Dates : 2003-01-23/2003-01-27 Notes : 6.9 Standard Type : H-MASER Input Frequency : 5 MHZ Effective Dates : 2003-01-28/2004-08-20 Notes : 6.10 Standard Type : RUBIDIUM Input Frequency : 5 MHZ Effective Dates : 2004-08-20/2004-08-25 Notes : 6.11 Standard Type : H-MASER Input Frequency : 5 MHZ Effective Dates : 2004-08-25/2008-12-12 Notes : 6.12 Standard Type : RUBIDIUM Input Frequency : 5 MHZ Effective Dates : 2008-12-18/2009-05-19 Notes : 6.13 Standard Type : H-MASER Input Frequency : 5 MHZ Effective Dates : 2009-05-20/2010-04-07 Notes : 6.14 Standard Type : H-MASER Input Frequency : 5 MHz Effective Dates : 2010-04-07/2010-11-11 Notes : 6.15 Standard Type : INTERNAL Input Frequency : Effective Dates : 2010-04-07/2010-04-07 Notes : 6.16 Standard Type : INTERNAL Input Frequency : Effective Dates : 2010-11-11/2010-11-23 Notes : 6.17 Standard Type : H-MASER Input Frequency : 5 MHz Effective Dates : 2010-11-23/2012-03-14 Notes : 6.18 Standard Type : INTERNAL Input Frequency : 5 MHz Effective Dates : 2012-03-14/2012-03-19 Notes : 6.19 Standard Type : MASER Input Frequency : 5 MHz Effective Dates : 2012-03-19 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 : 7. Collocation Information 7.1 Instrumentation Type : VLBI Status : PERMANENT Effective Dates : 1991-01-19 Notes : 7.2 Instrumentation Type : SLR Status : MOBILE Effective Dates : 1993-05-20/1993-09-30 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 : 8. Meteorological Instrumentation 8.1.1 Humidity Sensor Model : HMP-35A Manufacturer : VAISALA Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy (% rel h) : 2.0 (% rel h) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2003-01-22 Effective Dates : 2003-01-01/2004-06-16 Notes : 8.1.2 Humidity Sensor Model : HMP-35A Manufacturer : VAISALA Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy (% rel h) : 2.0 (% rel h) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2004-05-27 Effective Dates : 2004-06-16/2005-02-08 Notes : 8.1.3 Humidity Sensor Model : HMP-35A Manufacturer : VAISALA Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy (% rel h) : 2.0 (% rel h) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2005-02-04 Effective Dates : 2005-02-08/2006-06-16 Notes : 8.1.4 Humidity Sensor Model : HMP-35A Manufacturer : VAISALA Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy (% rel h) : 2.0 (% rel h) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2006-03-01 Effective Dates : 2006-11-21/2009-01-08 Notes : 8.1.x Humidity Sensor Model : Manufacturer : Serial Number : Data Sampling Interval : (sec) Accuracy (% rel h) : (% 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 : 8.2.1 Pressure Sensor Model : PTB-100A Manufacturer : VAISALA Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy : 0.0 (hPa) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2003-01-22 Effective Dates : 2003-01-01/2004-06-16 Notes : The readings are modeled as a function of the : pressure transducer output and the : temperature. 8.2.2 Pressure Sensor Model : PTB-100A Manufacturer : VAISALA Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy : 0.0 (hPa) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2004-05-27 Effective Dates : 2004-06-16/2005-02-08 Notes : The readings are modeled as a function of the : pressure transducer output and the : temperature. 8.2.3 Pressure Sensor Model : PTB-100A Manufacturer : VAISALA Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy : 0.0 (hPa) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2005-02-04 Effective Dates : 2005-02-08/2006-03-02 Notes : 8.2.4 Pressure Sensor Model : PTB-100A Manufacturer : VAISALA Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy : 0.0 (hPa) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2006-02-08 Effective Dates : 2006-03-02/2009-01-08 Notes : The readings are modeled as a function of the : pressure transducer output and the : temperature. 8.2.x Pressure Sensor Model : Manufacturer : Serial Number : Data Sampling Interval : (sec) Accuracy : (hPa) Aspiration : Height Diff to Ant : (CCYY-MM-DD) (m) Calibration date : (CCYY-MM-DD/CCYY-MM-DD) Effective Dates : Notes : 8.3.1 Temp. Sensor Model : YSI 44212 Manufacturer : YSI Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy : 0.0 (deg C) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2003-01-22 Effective Dates : 2003-01-01/2004-06-16 Notes : 8.3.2 Temp. Sensor Model : VSI 44212 Manufacturer : VSI Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy : 0.0 (deg C) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2004-05-27 Effective Dates : 2004-06-16/2005-02-08 Notes : 8.3.3 Temp. Sensor Model : VSI 44212 Manufacturer : VSI Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy : 0.0 (deg C) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2005-02-04 Effective Dates : 2005-02-08/2006-11-21 Notes : 8.3.4 Temp. Sensor Model : VSI 44212 Manufacturer : VSI Serial Number : XXX Data Sampling Interval : 900 (sec) Accuracy : 0.0 (deg C) Aspiration : NONE Height Diff to Ant : 0 (m) Calibration date : 2006-03-01 Effective Dates : 2006-11-21/2009-01-08 Notes : 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 : 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 : 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/BUILDLINGS/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 : NRCan/GEODETIC SURVEY OF CANADA Preferred Abbreviation : NRCan Mailing Address : 615 Booth Street, Ottawa,Ontario : Canada, K1A 0E9 Primary Contact Contact Name : Mark Caissy Telephone (primary) : 613-995-4024 Telephone (secondary) : Fax : 613-995-3215 E-mail : caissy@geod.nrcan.gc.ca Secondary Contact Contact Name : Peter Taylor Telephone (primary) : 613-992-2106 Telephone (secondary) : Fax : 613-995-3215 E-mail : peter.taylor@geod.nrcan.gc.ca Additional Information : 12. Responsible Agency (if different from 11.) Agency : (multiple lines) Preferred Abbreviation : (A10) 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 : NRCan URL for More Information : http://www.geod.nrcan.gc.ca/index_e.php Hardcopy on File Site Map : Site Diagram : Horizon Mask : Monument Description : Site Pictures : Additional Information : Antenna Graphics with Dimensions Type: AOAD/M_B (Allen Osborne Design) ----- / + \ <-- 0.096 L2 | + | <-- 0.078 L1 +-----------------+-------------+------------------+ <-- 0.070 TCR | | | | | | | | | | +-----------------+------x------+------------------+ <-- 0.000 BPA | | +-------------+ <-- -0.011 || || <-- 0.351 --> Type: AOAD/M_T --- L2 Phase Center => / + \ <---------------+ L1 Phase Center => | + | <---------+ | +----------------------------------------------+ | | | | | | | | | | | | | | | | | | ================================================== | | | | | | | +-+ | | 0.228m Bottom of Preamp. (BPA) => +====| |====+ <--+ | | | | | 0.210m | | | | | | | | | | | Mount => | | 0.100m | | | | | | | | | | | | | +-+ | | | | Monument => +----------------+====| |====+-----------------+ <--+-----+ Ref. Point | | | | | | | Concrete pillar | | | | | | | BPA: Bottom of Preamplifier L1 : L1 Phase Center L2 : L2 Phase Center TCR: Top of Chokering BCR: Bottom of Chokering