Bienvenido al blog de GNSS

En esta sección escribimos artículos y comentarios sobre el mundo de GNSS, GPS, GLONASS, Galileo, Location Based Services (LBS), proyectos en las Islas Canarias, estudios de la Macaroneisa y Africa Occidental, y otras cosas que se nos ocurran!. Podeis dejar vuestros comentarios y correcciones con cada artículo. Esperamos que estas páginas se conviertan en un punto de reunión para todos los usuarios de GNSS alrededor del mundo.

Tambien esperamos tratar temas de GIS (Servicios de Información Geográfica) y georeferenciación en general.

Saludos,
Ignacio Romero Trujillo
Director


4 new Galileo satellites

This year we have had two successful Galileo launches one on 27 March and the second on 11 September.  It is good to report that these 4 satellites were delivered to the correct orbits as opposed to the launches last year (more on those below!) The 27 March launched delivered satellites E26 and E22 to […]

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At the GA !!

This week I am here in Australia helping my friends an international colleagues of the Geoscience Australia (GA) Geodesy section. They are working hard to design and code their own GNSS processing software, and I am helping them on project and quality management issues, which for such a complex software project are very important so […]

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Galileo 5,6 launch and orbit update

The satellites are operational as described in today’s ESA press release it indicates that the satellite finally opened their solar panels (there had also been a problem with that!) I have created 3D images on an excellent iPad application called ‘Orbit Architect’ which I can recommend to everyone as a great tool and wonderful to […]

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Galileo bad orbit insertion

Unfortunately the launch of the two latest Galileo satellites has left a very bad taste in our mouth. The entire GNSS Community was looking forward to the next step in the Galileo constellation deployment. The launch went well from French Guyana aboard the Soyuz rocket, but apparently something went wrong at the orbit insertion point […]

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AGU2013 IGS Infrastructure Committee poster

From 9 to 13 December I participated in the AGU Fall Meeting 2013 presenting a poster of some interesting IGS work. As the IGS Infrastructure Committee Chairman I have coordinated an experiment together with the IGS Network Coordinator, the Reference Working Group, the Antenna Working Group, and the Analysis Center Coordinator. The experiment consisted on […]

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TELECAN project comes to a close

For the last 12 months our company has been in a collaboration project with the University of Las Palmas in a project called TELECAN. This activity does not have a GNSS component at this time but it has been a fantastic learning experience for our company in the filed of Earth Observation, and it has […]

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The CGC continues to grow

Public GNSS data availability for the African continent has been a significant issue for sometime. Due to lack of a good communication infrastructure it is difficult to establish, operate and maintain permanent GNSS stations in our continent. (Yes as a person from the Canary Islands I consider myself geographically African as we have the mainland […]

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IGS Workshop 2012

This past July we held the IGS workshop in Poland at a beautiful location about 3 hours from Warsaw at the university were Copernicus taught, amazing. The location was beautiful, the organization very efficient and the attendance was very good. As seen in the image I gave a nice presentation on the state of the […]

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IGS MGEX Project

The IGS has created a new project called MGEX to gather and process multi-GNSS data. IGS MGEX stands for Multi GNSS Experiment and it was proposed and is managed by the IGS GNSS Working Group. The main aim is to collect GNSS data containing more than GPS+GLONASS data. Currently there are a multitude of modern […]

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IGS Co-located Station Antenna Tests

GNSS stations of the IGS are very important, especially when they are located at locations with other space techniques such a Satellite Laser Ranging (SLR) and Very Long Based Interferometry (VLBI), which all provide inputs to the establishment of the Earth’s International Reference Frames. The ‘ties’ between all the different antenna’s reference points is essential […]

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P1C1 biases from different sources

Coming back to this issue we have encountered a significant problem. As remarked before in this blog P1C1 biases we have to be able to correct the C1 measurements from GPS to mix them correctly with the P1 measurements. This comes from the fact that when the signal is encoded in the satellite there is […]

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IGS positioning on phase aligment for GPS L2 data

The members of the Infrastructure Committee have prepared the following statement which was distributed to the receiver manufacturers late in 2010 by the IGS Governing Board: “ The IGS urges all GNSS receiver manufacturers to adopt a standardized phase alignment practice for all GNSS signal modulations common to a given carrier frequency, in order to […]

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PRN22 Signal Anomaly

It has been reported over the last few days of 2010 that satellite PRN22 (G22, SVN 47) has had issues. Essentially the satellite had an issue with its navigation signal in that the Differential Code bias had changed a whole lot! this meant that the P1C1 biases we were all applying to be able to […]

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Rinex Observables

What an issue!! We are facing a very significant problem in the current Rinex data files , and I need to tell you about it! The Rinex 2.11 format is defined without regard to where the phase is actually coming from (the C/A or the P code tracking). This has for the longest time not […]

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Eumetsat Meteo Satellite Conference

I just attended the Eumetsat Meteo Satellite Conference in Cordoba, Spain at a beautiful location right by the Mezquita. The event brings together many satellite Meteo researchers. As you know most Meteorological satellites carry on-board many different scientific instruments, and this conference brings together a very heterogeneous group of scientific people which as very informative […]

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IGS Workshop 2010

This entry is very late, sorry for that. Let me share with you my two presentations at the IGS Workshop, 2010 held in Newcastle in 2010. I gave a presentation on the overall state of the IGS Infrastructure up and down the Rinex data chain, considering both the challenges faced by the station operators, the […]

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IGS Station Height Tests

The IGS permanent GNSS stations are the backbone of the IGS as they provide the overwhelming bulk of the satellite observations used for the IGS products; orbits, clocks, station positions, TZD, etc. The station GNSS receivers record the measurements from the satellite constellations (GPS and GLONASS) as correctly as possible. This means following the IGS […]

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Monitoring the Sky for Astronomy with GPS

SAC has continued to support the IAC (Instituto Astrofisico de Canarias) by calculating the Precipitable Water Vapor (PWV) at the Observatorio Roque de los Muchachos (ORM) in La Palma. The island of La Palma is about 250 Km from Gran Canaria where SAC is based, both in the archipelago of the Canary Islands, Spain, of […]

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IGS Infrastructure Committee / Comité de Infraestructura del IGS

I was honored by my IGS colleagues last year by being selected as the first IGS Infrastructure Committee Chairman. This is a great honor and I hope to be able to make the IC relevant and responsive within the IGS to all infrastructure issues. At the IC 13 IGS members are tasked with providing advice, […]

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PRN01 … not quite working as expected

PRN01 is one of the latest GPS satellites launched on 24 March 2009. Over the summer we have been investigating what the deal is with this satellite which is still not set to healthy. When a GPS satellite is launched it goes through a period of a few weeks of commissioning. This period involves in-orbit […]

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GPS-GLONASS biases … a receiver issue

GNSS receivers decode all the signals ‘more or less’ at the same time, the time is really set by the GPS but the other systems (Glonass) have a bias so that apart from the clock bias per satellite there is an inter-system bias between the constellations (at least that is what we thought!! here is […]

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At the EGU General Assembly 2009

I was just at the European Geophysical Union General Meeting (EGU) in Vienna, Austria. At this meeting there was a strong presence from ESA/ESOC as both Tim Springer and myself had presentations in the Geodesy section and I took a poster for the CGC (Canary GNSS Centre). My presentation covered the IGS Reprocessing (the repro1 […]

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GPS launch opens new capability

New GPS satellite!! The launch and start of operations of the new SVN49/PRN01 is excellent news. You can follow the report on the news of the launch here, for example: Delta II launches penultimate GPS-IIR satellite. This satellite is interesting because it has an experimental L5 signal transmitter. This would be the third signal for […]

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SAC helping the ESA/ESOC GPS Reprocessing

The IGS Reprocessing is a fantastic activity which I have highlighted before in this blog. The IGS reprocessing involves recalculating all the GPS products (Station coordinate files, Satellite orbits, Station and Satellite clocks and Earth Rotation Parameters). Most of the IGS Analysis Centers are participating in this effort to take all the IGS GPS data […]

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Vapor de Agua sobre Observatorio Roque de los Muchachos (LPAL)

En SAC hemos estudiado los datos de la estación LPAL, La Palma, con el objetivo de caracterizar la cantidad de vapor de agua en la atmósfera cerca de los observatorios astronómicos. Este estudio ha sido realizado para el Centro GNSS de Canarias a partir de una pregunta del Instituto de Astrofísica de Canarias. La estación […]

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What is EGNOS?

I was asked this question at a job interview many years ago and I did not know the answer … I didn´t get the job, but I have no regrets! let me explain a bit … The European Geostationary Navigation Overlay System (EGNOS) is an enhancement and extension of GNSS (GPS/GLONASS). It is the European […]

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IGS reprocessing, an exciting project!

After the IGS workshop which we recently concluded to great success, one of the most important and interesting activities for the near future is the reprocessing of all the historical IGS data using current state-of-the-art techniques. Reprocessing of GPS data back to 1994 is a high-priority of the IGS since modern techniques can better estimate […]

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The CGC Station Information System

I am proud to present to you the CGC Station Information System, a web-based monitoring system that we have developed at my company for the CGC. The system has a main page to show all the stations being mirrored at the CGC server. The data from all these stations are available through the CGC in […]

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IGS Workshop 2008 Contents & Summary

I intended to write a daily summary from the 2008 IGS Workshop which just closed. Unfortunately that was optimistic I was too busy to have the energy to write at the end of each day! Therefore I have written a document with my summary of each day, please download the document below and read at […]

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The IGS Workshop 2008

Today the IGS Workshop kick off in the beautiful Ritz-Carlton Hotel in South Beach, Florida. The Workshop is a small, dedicated, single-session gathering of most of the IGS people involved on: station network management, product generation, and new activities (real-time, antenna calibrations, etc). This meeting takes place every 2 years and is organised by a […]

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Datos GNSS libres y abiertos de España

Un gran problema de los datos GNSS en España es que la mayoria no son libres y abiertos. Depende mucho de la zona, de la idiosincracia de cada sitio y de la “novedad” de las instalaciones. Las regiones con mas tradiccion y capacidad tienden a dar accesso libre a sus datos, otros no. Creo que […]

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Data Policy – Política de Datos

Política de Datos es la especificación clara y por escrito por la institución que instala una estación permanente GNSS para que los datos recabados sean de dominio público en algun momento. Especificando un tiempo determinado para acceder a los datos es fundamental para que los datos, que normalmente se han pagado por todos los contribuyentes, […]

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Estaciones GNSS en Canarias

Recientemente desde SAC y el CGC hemos escrito un documento general sobre el posible desarrollo de la red de estaciones GNSS Canarias, por favor descargeselo y haganme llegar sus comentarios y opiniones: Estaciones GPS Canarias 3.0 La idea fundamental del documento (white paper) es explicar los beneficios de tener una red de estaciones de financiación […]

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P1-C1 bias … and other Code biases

The C/A code and the P code encoded in the L1 “should” be coincident so that a pseudo-range derived with the C/A code; “C1″ should be equivalent to one derived with the P code; “P1″ so that we could use them interchangeably, in the IGS we agreed years ago to use P1,P2 & L1,L2 to […]

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It’s official Space is no longer free …

I wrote recently a post on the dangers of militarising and claiming Space as an area that needs active defence strategies. Those fears came at that time from the recent actions by China claiming all space over its country (to what height is as of yet unknown!) and also the event of China having shot […]

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Vehicle management using GPS … my experience so far.

I have recently added vehicle management to my own car! and let me tell you about it … it is an interesting experience but the system has some way to go before it is truly useful. I was investigating representing a new fleet management service from mainland Spain in the Canary Islands. The islands are […]

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GIS applications

Geographical Information Systems, GIS, is the new buzz word … these are systems that add location based services to a digital map. Basically anything that superimposes services with precise location over a map is a GIS and some are quite amazing! Basically a GIS presents location bbased information over relevant cartography. Different service providers, public […]

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Space is not free anymore ??

We all heard about the Chinese destruction of their own weather satellite with a guided missile from the ground. While this appeared impressive the details of the technology were not clear for some time. Hitting a fast moving target is very hard, obviously, but if its yours so you know exactly where it is or […]

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Satellite Navigation current status

The situation with the Global Navigation Satellite Systems is not easy to predict so for now just explaining the current situation may illuminate what could happen in the near future. We currently have only free signals. This is sometimes lost on regular users, the two flying constellations GPS and GLONASS offer services that are essentially […]

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Selective Availability OFF forever

I was a recent arrival to the GNSS field in the year 2000 when president Clinton turned off by surprise, to us at ESA at least, the SA degradation to the GPS satellite clocks. At that time at the IGS we were only estimating orbits and clocks and for our work this SA-off had no […]

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Galileo has the money!!

It was obvious that at this stage we are not going to stop Galileo but how to pay for it was never a trivial matter. Even though the system will cost significantly less than a line of high-speed rail its seems like satellite based systems have a harder time of finding money than land-based transport […]

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GGTO – an interesting correction

It turns out, as reported by Inside GNSS (Sept/Oct 2007), that of course the GPS and Galileo time-scales will not be the same. GGTO is the GPS-Galileo Time Offset The navigation solution calculated by receivers using signals from both navigation systems will incur in an error if the GGTO is not accounted for. The Galileo […]

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GPS Control Center updated!

Finally the GPS Control Center has been updated so that it can deal with the increasing numbers of active satellites. No doubt this is an excellent development as it comes together with improved navigation messages (they have been improving for some time now) and better management of satellite outages.

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Where is GNSS heading

We currently only have GPS flying complete and after many years working with GLONASS (at ESA/ESOC we are one of only two worldwide Center’s estimating GLONASS orbits continuously for over 7 yrs), I am not too optimistic that GLONASS will deploy a complete constellation anytime soon. We have been going from GLONASS constellation of 14 […]

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RealTrack football (I mean soccer!)

I am proud to highlight this product from my home country, I am of course spanish and this company is from Almeria in southern spain. The product RealTrack football is a real-time traning system using GPS positions of each to aid in training regimes, total distances covered, tactical mapping using the recorderd positions of the […]

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what GNSS signals do we have …

It is interesting sometimes to take a step back and remember what signals we actually have as they limit completely what we can accomplish. It has been amazing what engineers worldwide have been doing with these basic and limited signals. Noone at the start of GPS could have imagined the number of applications and how […]

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On the real Galileo benefits

Satellite Navigation cannot improve with just one system. No matter how well GPS has worked so far it is becoming antiquated and could be surpassed in terms of signals in space by GLONASS in the very near future. It is VERY difficult for any user community to have ANY impact on any decision in the […]

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GLONASS and GPS differences

You have probably already heard that there are actually TWO satellite constellations providing positioning signals available to everyone. the first is the well-known American GPS and the second is the Russian system GLONASS. Both system do exactly the same thing. They provide a signal-in-space beamed down to earth from so-called Medium Earth Orbit (MEO) using […]

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Semana Geomatica

Hemos estado en la Semana Geomatica que tuvo lugar en la Fira de Barcelona del 20 al 23 Febrero, y tambien hemos participado en el evento de CTAE (Technology Centre for the Aeronautical and Space industry) que organizó un evento para empresas de GNSS el 21 Feb en las mismas instalaciones. Las presentaciones tecnicas sobre […]

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The Canary GNSS Centre (Centro GNSS Canarias)

SAC is participating with other institutions to create and maintain the CGC, a non-profit centre which aims to educate and promote the use, collection and analysis of GNSS (GPS, GLONASS, Galileo) data for our geograhical area. The CGC aims to collect all the GNSS data from our region: The Macaronesia and Western Africa, the data […]

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NAVITEC Workshop Report

I just attended the ESA sponsored NAVITEC Workshop which is a very welcome effort to bring together mainly european efforts in GNSS signal processing, applications and hardware. The workshop was well attended and the atmosphere was cordial and welcoming. Many old faces on the European GNSS field take these opportunities to meet-and-greet each other, and […]

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GNSS Antenna Phase Centre corrections

For precise GPS positioning and scientific applications it is important to recognize that the antenna phase centers do not represent fixed points with respect to the antenna reference marker (neither at the emitter end or at the receiver end). The antenna phase center is the point where the receiver detects the signal and on the […]

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What is GNSS about …

For general information to the beginner I want to stress in this post the fundamentals. I feel like they are often forgotten, and this is the most fundamental concept; ” It is all a matter of time!” With that phrase I mean to say that GNSS position is only possible because we measure the time […]

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GNSS options

When buying a new receiver for precise applications (where sub decimeter precision is needed) it makes sense to get a multi-constellation receiver. A multi-constellation receiver takes the signals from the GPS and GLONASS satellite navigation constellations to calculate the receiver’s position more precisely and more robustly. In environments where the open-sky visibility may be compromised […]

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Navigation and P-commerce

Position and Navigation are the latest addition to the new economy, it is becoming necessary to be able to position every valuable item in the economy. This will be accomplished by GNSS services in the next decade. An additional benefit will be the ability of certifying a position whenever it is needed. For example proving […]

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Canary Advanced Solutions starts!

The core business of SAC is Satellite Navigation; GPS, GLONASS, Galileo. An expert recently commented that we are moving from the “information age” to the “position age”, all the same information will be available but we will be able to add value and context by including accurate certified position and time information. In critical and […]

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Soluciones Avanzadas Canarias arranca!

Lo que más nos motiva en Soluciones Avanzadas Canarias es nuestra area de trabajo: La Navegación por Satélite : GPS, GLONASS, Galileo. La navegación por satélite presenta una serie de oportunidades fantásticas en el futuro próximo. Estamos pasando de la era de la “información” a la era de la “posición”. Los mismos paradigmas seguirán existiendo […]

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