4.2.4 GPS Hardware for Surveying:

SOME INSTRUMENTATION (LEICA)


Leica Geosystems is the current company name of a venerable company that has since the 1920s specialised in optical surveying instruments. The original company was WILD, headquartered in the town of Heerbrugg, Switzerland.

Leica/Wild has been involved in GPS technology since the late 1980s, when it manufactured the Wild WM101 (and the dual-frequency version, the WM102) in partnership with the Magnavox Corporation. The software was known as PoPS. Magnavox was an electronics company based in Torrance, California, and is a GPS "pioneer". In the early 1990s the Magnavox company was offered for sale, and the civilian GPS assets were purchased by the Leica company. Apart from maintaining the development and marketing of certain GPS navigation products originally belonging to Magnavox (now under the Leica name), Leica has focussed on the surveying market where it has a very strong presence and a high reputation for quality engineering and service.

The first GPS surveying products were the Leica System 200 and System 300. In 1998 Leica released the System 500. The data processing software is known as SKI (the latest generation SKI-Pro).

There are several different models in the System 500 "family", but as a result of the modular design it is possible to upgrade from the basic, single-frequency model (the SR510) through the dual-frequency, geodetic model (the SR520), up to the real-time, dual-frequency model (the SR530). The photographs below show the various configurations that are possible for the System 500 family of receivers (pole mounted, backpack mounted, tripod mounted).

Recently a field unit optimised for GIS coordinate and data attribute capture, the model GS50, was released. It consists of a terminal similar to the TR500 (right) but with special GPS/GIS data capture software.

  

Leica System 500 configurations.

 

 

 

 

 To address the precise navigation market, for machine guidance and control, Leica also released the MC1000 ("machine control") receiver. The rugged construction makes it ideally suited for mounting on heavy machinery. Such an instrument is intended to address the new applications in engineering construction, precision agriculture, opencut mine operations and other field robotics. The real-time kinematic solutions are available with very little latency (claimed to be less than 30 milliseconds), and at a rate of 10Hz (ten times per second).  

A variation of the MC1000, known as the CRS1000 ("continuous reference station"), has also been released. In addition to much of the functionality of the MC1000, special control software and massive onboard memory permits it to be used as a permanent reference station to support geodesy, surveying and precise navigation users. It is connected to a choke ring antenna.

 


The CRS1000 with choke ring antenna.


Further details of these and other products can be found on the Leica web site.



LEICA GPS System 500


Manufacturer: LEICA, Heerbrugg, Switzerland, and Torrance, California, USA.
Applications: All survey and geodesy applications.
Components: Modular design with SR510, 520 or 530 sensor, TR500 terminal, coms unit, and single or dual-frequency (including choke ring) antennas.

Features:

  • Precision: ±(3mm + 0.5ppm) for static GPS, ±(5mm + 1ppm) for "rapid static" solutions, ±(10mm + 1ppm) for "stop & go" & "kinematic" solutions, decimetre level code-based DGPS accuracy.
  • Tracks up to 12 satellites on both L1 & L2 frequencies (12 channels each). C/A (narrow-correlator technology), P1 & P2 pseudo-ranges. L1 phase tracked by reconstructing carrier via C/A code. L2 phase tracked by: (a) P code-correlation (when AS off), or (b) Leica proprietary codeless technique (when AS on).
  • Can support post-processing as well as RTK (the SR530), as well as RTCM-based DGPS.
  • Modes and applications are static, rapid static, kinematic, OTF kinematic, DGPS.
  • TR500 terminal displays 12 lines of 32 characters, QWERTY keyboard, weight 0.4kg (1.15kg when connected to the SR5x0 directly or by cable).
  • Camcorder batteries, each 3.6Ah/6V, powering the SR520 & TR500 for about 7.5 hours.
  • Software: SKI-Pro post-processing software.
  • Hardware and software can be seamlessly upgraded from the SR510, to the SR520, to the SR530.

 

Back To Chapter 4 Contents / Next Topic / Previous Topic

© Chris Rizos, SNAP-UNSW, 1999