RTK Tide Basics

One of the fastest emerging trends in hydrographic surveying is the use of the vertical component of RTK GPS to determine real-time water level corrections. There are currently several district offices of the US Army Corps of Engineers using this technique in place of conventional tide measurements.The main purpose of this article is to explain some of the basics behind the technique (without getting overly technical) and to point out some of the benefits and drawbacks to the method. The Basics Looking at Figure 1, let’s define the following terms: For simplicity, I am ignoring the heave-pitch-roll of the vessel... (read more)

2008-01-01 01:00:00

RTK Tide Basics

One of the fastest emerging trends in hydrographic surveying is the use of the vertical component of RTK GPS to determine real-time water level corrections. There are currently several district offices of the US Army Corps of Engineers using this technique in place of conventional tide measurements.The main purpose of this article is to explain some of the basics behind the technique (without getting overly technical) and to point out some of the benefits and drawbacks to the method. The Basics Looking at Figure 1, let’s define the following terms: For simplicity, I am ignoring the heave-pitch-roll of the vessel... (read more)

2008-01-01 01:00:00

Brazilian RTK GNSS Receiver

GEO TAG Engenharia (Brazil) has introduced the new multi-constellation RTK GNSS receiver GEO TAG MT.Pro. A pair of Trimble's Maxwell 6 chips provide most accurate and precise positioning and navigation and capable of receiving GPS, GLONASS and Galileo (-ready) satellite signals. The MT.Pro receiver is created for professional and precise positioning applications include land/marine surveying, construction and machine control, agriculture and infrastructure monitoring. The GEO TAG MT.Pro receiver is designed to allow centimetre-level positioning and dual-antenna inputs for precise heading. Other key features are high-precision, differential positioning accuracy subfoot-level and subdecimetre-level with OmniSTAR; heading accuracy up to 0.05°;... (read more)

2011-06-08 09:48:37

C-Nav RTK-Extend

C-Nav has launched RTK Extend for the C-Nav3050 GNSS receiver. RTK Extend ensures uninterrupted RTK observations in the event of short term communication loss between base station and rover. By eliminating annoying communications breaks due to obstructions, interruptions to line-of-sight, trees and other physical interference, RTK Extend ensures maximum production rates with minimum downtime. RTK Extend is ideal for measurements in high-risk activities or situations demanding continuous uninterrupted measurement and extreme accuracy counts.RTK Extend technology exploits the worldwide availability of C-Nav's PPP Corrections Service to compute simultaneously both RTK and C-Nav Real Time GNSS corrections. In the event of a... (read more)

2010-12-15 02:48:32

Network RTK Repeater Using Radio

Settop, Spain, has announced the release of the new SETTOP Repeater version. Settop Repeater allows Rover-RTK network users working in areas of low or no GSM coverage to receive differential corrections via radio. The firmware update allows the possibility to connect any external radio model from the market and connect the Settop Repeater to precision positioning systems or machine control. Repeater field application versatility is managed by an intuitive software controlled using a touch screen. Hardware design and field applications versatility make Settop Repeater a solution for land surveying applications, marine works, control machinery and agriculture. (read more)

2013-06-19 01:39:41

Stand-alone RTK GNSS Receiver

Seabed, The Netherlands, has released a new global navigation satellite system (GNSS) receiver, the SGR6. This system has a Novatel technical base. The SGR6 is a stand-alone metre-level to RTK centimetre-level positioning system, and provides numerous interfaces including RS232/RS422 serial ports, Ethernet access, with web interfacing. The SGR can also be adapted with a second antenna to provide heading and attitude. The SGR6 is the most advanced GNSS receiver within Seabed’s product line, the fully featured SGR6 provides the flexibility to meet your unique positioning demands. It works with a multi-constellation and multi-frequency platform. With 240 channels and comprehensive tracking... (read more)

2014-09-26 09:27:40

Precise RTK GPS Water Levels

Incline plane models in geoid-ellipsoid separation calibration

As more people adopt RTK GPS technology for measuring water levels, the issue of ellipsoid-geoid separation is increasingly being discussed. This article outlines various projects undertaken to calibrate this separation, and presents information to consider when using RTK GPS for measuring relative to an orthometric (geoid) datum. RTK GPS is increasingly being used for measuring water-level corrections during hydrographic survey, as for water levels in general. Measuring this third vertical dimension usually requires local site calibration to correct for separation between WGS84 ellipsoidal height and geoidal elevation, enabling conversion of WGS84 heights to orthometric heights such as mean seal level... (read more)

2008-01-01 01:00:00

GPS/GLONASS RTK Receiver Module

The Ashtech MB100 GNSS board has been developed for applications when power consumption, size and dependable performances such as raw data quality, real-time positioning (SBAS up to RTK) or GNSS heading + pitch/roll determination are critical. The MB100 is designed to address L1 GPS+SBAS applications - including heading + pitch/roll determination. Ashtech’s Z-Blade Technology and dual-frequency GPS configuration offerlong-range RTK performance, while single-frequency GPS + GLONASS configuration provides more satellites in view for demanding environments. Embedded Z-Blade GNSS centric technology uses all available GNSS signals equally, without any constellation preference, to deliver fast and stable solutions. The MB100 works as... (read more)

2013-06-06 10:10:46

RTK River Bathymetry in Africa

From Syledis and Tide Gauge to RTK GPS Water-level Corrected Survey

This article describes the installation of a hardware and software system for bathymetric surveys in the maritime part of the Congo River. The ‘Regie des Voies Maritimes’ (RVM) is a Congolese public administration in charge of an operational navigation river lane in the Congo maritime reach. The Congo River has the second largest flow in the world and is 4,700km long. RVM maintains the conditions for commercial navigation in the so-called ‘maritime area’, from the mouth to Matadi harbour, over a distance of 150km. The estuary is the only maritime border of the Democratic Republic of the Congo (DRC), with... (read more)

2007-11-27 12:00:00

Altus Next-generation GNSS RTK Receiver

Altus Positioning Systems, USA, has launched its next-generation APS-NR2 GNSS RTK receiver. According to Altus CEO Neil Vancans, this device provides an unprecedented combination of performance and features that make it ideal for a wide range of applications. As it does not need a connection to the Ntrip server it can, according to Altus’ specifications, work over 30 percent faster than other systems. It works on virtually all RTK networks. It has a dual cellular antennae with automatic switchover eliminating downtime due to signal loss. The built-in Wi-Fi enables to configure and monitor the unit and stream data directly to... (read more)

2014-10-28 08:49:01