• Are there enough satellites displayed and are they distributed across the sky?
• Do you have enough distance to shadowing (edge of forest, houses, masts, ...) that could interrupt the connection to the satellites?
• Are there highly reflective surfaces in the vicinity? These can distort the position
• Is a thunderstorm coming? The unstable atmosphere can lead to very inaccurate measurements
• Are you under or near a high-voltage power line? The electromagnetic fields can interfere with signal reception.
• Are you indoors? GNSS generally does not work indoors.
• For positions that are off by several 100m or km: Are you within the sphere of influence of directional and/or amateur radio stations? A military exercise? (Signal jamming)

At https://shop.swipos.ch:

• Sensor map: Status of the stations
• swipos status: announced maintenance
• I95 Ionosphere: Activity of the ionosphere
• IRIM/GRIM: Ionospheric and geometric errors on a VRS

At https://api.swipos.ch/health:

• Are the mount points OK

Main users can log in at https://shop.swipos.ch . There, in the swipos web interface, you can

• set the e-mail address for resetting passwords
• Assign passwords for the additional licenses

Attention! Existing passwords cannot be viewed in the swipos web Interface.

Without logging in, a new password can be ordered for each login. This password will be sent to the e-mail addresses stored in the swipos UI. Important: You must also change this password at the GNSS receiver!

Instructions changes in the password management

Yes, it is mandatory to disconnect from the swipos service, otherwise the billing will continue. For information on how to do this, please consult your operating manual or the reseller.

The positioning service results in a data volume of approx. 3MB/working hour for RTCM3 and NTRIP.

It is recommended to make sure that the mobile phone provider you choose offers good coverage in your area.

Make sure you have good signal quality (see above). In addition, you can increase the precision by using high-quality hardware and longer measurement times, as more data will then be available for evaluation.

Transmission formats:

• RTCM 3.1 for GPS, GLONASS
• RTCM 3.2 MSM4 for GPS, GLONASS, Galileo, Beidou

GNSS signals:

• GPS (L1, L2 & L5)
• GLONASS (L1 & L2)
• Galileo (E1 & E5)
• Beidou (B1, B2 & B3)

• Direct: LV95/LHN95
• Using HTRANS on the server: LV95/LN02

In order to obtain swipos positioning data, you first have to open an account with swipos. The order process is explained on the prices and ordering page, where you will also find the corresponding swipos order form.

With the user name and password which you will receive upon completing your registration, you can configure your Rover for swipos-GIS/GEO. You will find the applicable details on the swipos-GIS/GEO services page under «Access», «Rover configuration». You can conveniently print out all the necessary information by selecting the printer icon (at top right of the page).

swisstopo does not provide any receiver-specific data. For this purpose, please contact the seller or manufacturer of your receiver.

swipos-GIS/GEO transmits RTCM 3.x correction data (cf. Navipedia) to the Rover.

swipos-GIS/GEO VRS corrections are transmitted in the CHTRS95 global system. CHTRS95 corresponds with ETRS89 for epoch 1993.0. The data are available in the two height systems, LHN95 and LN02. On the Rover, transformation between CHTRS95 and CH1903+ / LV95 (the local Swiss reference system) is effected as follows:

• Application of the 3 translations (dX, dY, dZ) (no rotation, no scaling): you can look up the corresponding values via swipos-GIS/GEO under «Rover configuration»
• Application of Swiss projection LV95 (plane coordinates E, N, height) with an offset of 2,000,000 / 1,000,000
• Decision whether orthometric or ellipsoidal heights are required. It is possible that a geoid will have to be used, which can be obtained free of charge. Please note that some manufacturers already include the geoid correction internally on the coordinates.

The correct mount point has to be selected, depending on the desired height system.

swipos primarily communicates via e-mail and the Internet:

• https://swisstopo.ch/swipos - Information about services and prices, plus frequently asked questions
• https://shop.swipos.ch - swipos web interface
  • - Sensor map: automatically updated station
      status
  • - swipos status: if problems arise, we publish
      status reports during office hours
• E-mail (swipos newsletter):
  • - swipos newsletters are mailed twice a year
  • - swipos information bulletins are sent as
      necessary in order to report failures and
      maintenance work
  • - You can sign up via our web site to receive
      swipos newsletters and information bulletins (in
      German or French only). You are required to
      confirm your registration before you receive any
      newsletters and other reports from us.
  • - In order to ensure that our mailings do not land in
      your spam folder, we recommend adding the
      corresponding addresses - swipos@swisstopo.ch
      and sales.swipos@swisstopo.ch - to your address
      book.

• There are 2 height systems in use in Switzerland: the LN02 heights, which originate from 1902, and the more recent («modern») LHN95 heights. The latter are orthometric heights and are sometimes designated as H_orth.
• The national maps and cadastral survey use LN02, while for other geodata the applicable height system is indicated.
• LN02 and LHN95 heights differ significantly from one another; H_LN02 = H_LHN95 -H_TRANS. The H_TRANS value can be visualised on the map.geo.admin.ch web site.
• Further information: geoid, the Swiss reference frame and height transformations

For methodological reasons, height measurements are more challenging than position measurements. Further information on this topic (in German): cadastre.ch

Because positioning with GNSS calls for maximum precision, the volatility of the atmosphere during the summer months can give rise to variations, especially in the height component.

These height fluctuations are partly attributable to the VRS software swipos uses. During very hot days, or as the result of the passage of cold and warm fronts, the software is only able to model the atmospheric conditions inadequately. In Switzerland, modelling is extremely challenging due to the changes of the topography over a small area, and is thus only depicted to an inadequate extent by products available on the market.

The GRIM value (GRIM = Geometric Residual Integrity Monitoring), which indicates the geometric residual error (paths and troposphere) of the VRS network is a good gauge for assessing the quality of the modelling of the troposphere at the swipos service centre. During position calculation, a high GRIM value results in correspondingly higher positioning errors. GRIM values are updated hourly and posted online by swipos.

If you are planning a critical height calculation, we recommend doing this on a day during which the atmosphere is as stable as possible. If this is not possible, it is advisable to carry out the measurements in the morning (and perhaps repeating them later in the day for comparison purposes).

For construction sites, it is helpful to provide a reference point for the calibration of technical equipment. This point should be firmly secured and measured by a specialist. This makes it possible to verify the height and position accuracy before commencing construction or at frequent intervals. 

The RINEX data of the AGNES stations (AGNES = Automated GNSS Network for Switzerland) are available in the following reference system:

• Geocentric coordinates XYZ in CHTRS95 = ETRS89, version ETRF93 

swisstopo provides further information about CHTRS95 on its Swiss reference systems page.

swisstopo’s Permanent Network Information Service publishes the coordinates of each of the AGNES stations, here for example for the Zimmerwald station.

With swipos, measurements can be carried out with an acceptable degree of quality within a range of 5 to 10 kilometres beyond Switzerland’s borders, because the border stations of the neighbouring countries are integrated into the swipos solution (cf. Sensor Map).

Nonetheless, it is worth considering whether it makes better sense to use the correction service of the neighbouring country in question, especially in order to obtain coordinates in the local reference frame instead of the Swiss reference frame.

In particular, the height transformation (HTRANS) that runs behind the *LN02 mount points is not designed for use outside Switzerland, and it is not possible to make any meaningful statements concerning the result and accuracy of this HTRANS abroad.

Furthermore, all of Switzerland’s neighbouring countries have another height reference point, which is why it is not possible to directly compare heights in the different systems.

No, we do not offer support for hardware or software. Should you have any questions, please contact the seller or manufacturer concerned.

No, swisstopo does not supply SIM cards. You should conclude a contract with the telecommunications service provider of your choice. For real-time measurements, uninterrupted network coverage is especially important.

On the FAQs page you can also find information about the data volume to be anticipated.

If your system can read the RTCM 3.2 correction stream, which contains the data for GPS, GLONASS, Galileo and Beidou satellites, for swipos-GIS/GEO you can use the following mount points: «MSM_GISGEO_LV95LN02» or «MSM_GISGEO_LV95LHN95». We recommend using MSM mount points because these offer a larger number of satellites.

If your receiver is only compatible with RTCM 3.1, you have to use the «VRS_GISGEO_LV95LN02» or «VRS_GISGEO_LV95LHN95» mount points. These only contain data for GPS and GLONASS satellites.

«XXX_GISGEO_LV95LN02» and «XXX_GISGEO_LV95LHN95» mount points differ in terms of the utilised height reference frame. With respect to planimetry, both mount points are identical.

• The LN02 height system, which dates from 1902, is also referred to as the levelling height system (without gravity) and is Switzerland’s official height reference frame. 
• The LHN95 national height network dating from 1995 is a more modern height system with orthometric heights, while taking account of the CHGeo2004 geoid model.
• If you carry out tasks for the cadastral survey or work with heights from other geodata, in order to avoid errors we recommend that you use the LN02 height system.
• If you do not have an external height reference and only the relative height change is relevant, you can benefit from the use of the LHN95 height system without experiencing any problems.
• Further information about the height systems: Local Swiss reference frames

1. Log on to https://shop.swipos.ch
2. Select RINEX shop
3. New order
4. Select an AGNES station (CORS) or a virtual reference station (VRS) for the data download.
   a. For CORS: Select one or more AGNES stations
   b. For VRS: enter approximate coordinates of the desired station
   
5.  Then «Continue to time selection»
   
6. Here you can select the desired observation period. Please note that these are GPS times, i.e. you must convert your times to GPS (UTC). You will find tips on how to do this below.
7. In the next step, you can add more stations or more time periods.
8. You can then either download the data directly or receive it by e-mail.
9. «Generate Data» starts the process.
10.  If you are notified by e-mail, first check after the notification whether all requested data has been generated. Especially with large downloads, incomplete downloads can cause the calculations to fail.

If you have a swipos-GIS/GEO contract, you can also obtain a certain amount of RINEX data from the shop free of charge. 

With VRS you can position the reference station at any coordinates within Switzerland. With CORS you choose from the data of one of the AGNES stations in Switzerland.

The GPS time is almost the same as the Universal Time Coordinated UTC, but differs from it by the leap seconds.

The time difference to GPS time in Switzerland is 2h in summer and 1h in winter.

As an example:

• GPS Time: 2021-02-11T10:30G
• CET: 2021-02-11T11:30 (winter)
• CEST: 2021-05-11T12:30 (summer)

If you continue to work in the old coordinate frame LV03, you can transform data e.g. with REFRAME into the new coordinate frame LV95/LN02.

Please contact your reseller if you have any questions regarding the configuration of your receiver for the new LV95/LN02 coordinate frame.

Quarterly, depending on consumption. There is no provision fee.

As soon as your registration has been processed, you will receive a login with which you can order the data in the swipos-shop. The login will typically be sent to you on the following working day.

Please send any notices of termination or changes to the contract to us in writing, by post or by e-mail to sales.swipos@swisstopo.ch.

The flat-rate contract is valid for a minimum of one year and may be terminated thereafter with 30 days' notice from the date of signing.

Various tariffs apply, depending on how often you use the service and which application you have.

If you already know which service you require, you can consult the price list to view the applicable tariff.

Otherwise we recommend visiting the swipos services web site, where you can find out which services are available and can contact us if you have any specific questions.

To directly order swipos-GIS/GEO or swipos-PP, please complete the order form as a pdf or online. For swipos-INFRA, please contact us by e-mail.

You can also order swipos just as conveniently from a reseller. The required information will be exactly the same.

Yes, this is possible if you obtain all your licences from us. Please contact sales.swipos@swisstopo.ch

Some resellers also offer this option. Please ask your reseller for further information.