Oct 2001 |
Leica GPS System 530 purchased |
Three Leica SR-530 receivers plus accessories purchased.
The purchase entails a demonstration and two training
sessions. |
Dec 2001 |
First trial field campaign |
|
Jan 2002 |
Bernese GPS Software Version 4.2 purchased |
Bernese GPS Software Version 4.2 purchased and installed
on a Windows platform |
|
Pacific Crest radio modems (base and rover) upgraded
to governmental frequency |
Pacific Crest radio modems (base and rover) of the
450-470 MHz frequency range replaced by same type modems
with the governmental frequency range of 410-430 MHz.
The transmitting and receiving frequencies are set to
416.425 MHz and stored in Channel 0 of the modems. |
Feb 2002 |
Monument M40 becomes SLAC's master control station |
A Leica SR-530 receiver is installed permanently
in a weatherproof box attached to the wooden deck, a
Leica AT-504 choke ring antenna plus weather dome is
mounted on top of the monument. The weatherproof box
also houses the Pacific Crest base radio modem, a power
outlet, and an Ethernet connection (data download, however,
is done manually using the FlashCard of the SR-530). |
Mar 2002 |
Antenna mount changed |
The new mount is about 20 cm lower than the initial
setup. |
|
Weather dome removed |
Phase center variation tables for the AT-504 are
only available in versions without radome. |
Apr 2002 |
RTK Mapping begins |
|
Jun 2002 |
RTK Mapping presentation |
|
Jun 2002 |
Bernese Processing Engine (BPE) set up for daily
GPS solutions under Windows |
Daily solutions for a regional network are computed
using the Bernese Processing Engine (BPE) under Windows.
Processing performed when new observation data are downloaded
from the FlashCard of the SR-530. |
|
Precise coordinates determined for M40 at reference
epoch 2002.36. |
Precise coordinates determined for M40 at the reference
epoch 2002.36 |
Jan 2003 |
Leica RS-500 receiver purchased |
Following some tests, the RS-500 replaces the SR-530
in the weatherproof box (the SR-530 can now be used
as a rover unit). The GPS observations are continuously
logged. The RS-500 is controlled by Leica's ControlStation
software from a PC in the office. The necessity to connect
the RS-500 directly to the logging PC via RS-232 cable
is removed by employing an RS-232 Ethernet converter. |
Feb 2003 |
GPS-RTK operations verified using the RS-500 |
RTK correction signal is transmitted via the Pacific
Crest radio in the Leica format. |
Mar 2003 |
Second weatherproof box installed at M40 |
A second weatherproof box is installed at M40 to
accommodate an uninterruptible power supply (UPS). The
RS-232 Ethernet converter is moved to the new box as
well. |
Apr 2003 |
Bernese GPS Software Version 4.2 under Linux |
Bernese installed on Linux platform. The Windows/DOS
version is known to show instabilities in the BPE. This
problem was repeatedly observed doing the daily processing
of SLAC M40. |
|
ControlStation Monitor Program "monitor" installed |
"monitor" is an in-house product coded in Visual
Basic that monitors Leica's ControlStation software
for possible run-time errors (notifying the operator
by email in such a case) and performs a quality check
and a reformatting of the RINEX files. |
Jun 2003 |
Anonymous FTP space set up |
AFTP space at SLAC's computing center set up for
storing RINEX observation files. The storage capacity
amounts to 500 MB. |
|
Bernese Processing Engine (BPE) set up for daily
solutions under Linux, automatization enabled |
The data analysis runs in a fully automated mode
using the Linux scheduler for its daily run at 4 a.m.
local time. |
Jul 2003 |
Back-processing of daily GPS solutions |
All GPS data available to the current date are reprocessed
under Linux. |
|
|
|
|
Precise coordinates and velocities for M40 for the
epoch 2002.90 determined |
New coordinate and velocity values determined for
SLAC M40 using all available data. The reference epoch
2002.90 is in the middle of the used data window. |
Oct 2003 |
Logging PC replaced |
The old logging PC could not be upgraded to Windows
XP due to limited resources. All pertinent software
is ported to new Windows XP PC. |
Nov 2003 |
Disclaimer notice and DOMES number obtained |
Disclaimer notice put into AFTP space. DOMES number
obtained for SLAC M40 changing the official name to
SLAC 49523S001. All RINEX observation files have been
edited to reflect the name change as well as to contain
a reference to the disclaimer notice. |
Dec 2003 |
Output RTK data in CMR format |
Made CMR format data available on network from second
channel of RS-500 using serial to TCP/IP converter box. |
Feb 2004 |
Internal report on SLAC's permanent GPS station |
An internal report has been compiled describing
the data handling of SLAC's continuously operating GPS
station. |
Mar 2004 |
RTK correction signal format changed to RTCM V2.2 |
RTCM Version 2.2 (msg types 1 & 2 & 3 & 18 & 19
& 22) used instead of Leica format. With RTCM V2.2 the
transmitted reference station coordinates have sub mm
accuracy. Leica/CMR are good to 1 mm, RTCM V2.1 only
has cm level. |