Spire Lemur satellites constellation.

Commercial radio occultation third party pilot data service operational soon


Image credit: Spire

Spire Lemur satellites constellation.
Spire Lemur satellites constellation.

EUMETSAT's commercial radio occultation third party pilot data service will be operational from 14 February 2022.

Last Updated

22 March 2022

Published on

04 February 2022

Since 30 September 2021 EUMETSAT has disseminated in trial mode level 1b (bending angle) radio occultation data generated by EUMETSAT, based on raw measurements provided by Spire's nanosatellite constellation. During the trial period, access was limited to EUMETSAT Member State NMHS and ECMWF.

During the trial phase the data products were thoroughly validated in collaboration with ECMWF, ROM SAF and several Member States. In particular, EUMETSAT thanks DWD, DMI, the Met Office, and ECMWF for their valuable contributions that made the transition to the service's operational phase possible. The outputs of the validation can be found in the Product Validation Report (coming soon).

Data is available via:

EUMETCast Satellite HVS-1

Channel: E1H-TPL-1
Multicast address:
PID: 601

EUMETCast Terrestrial

Channel: T01-TPL-1
Multicast address:

From the start of the pilot service's operational phase, a minimum of 1,000 occultations are expected per day. These will be disseminated in BUFR format.

File names follow the WMO filename convention, and are formulated as follows:



  • <mission>: name of the mission or instrument (i.e. SPIRE in this case)
  • <sat>: Satellite ID performing the occultation measurement
  • <stime>: Start sensing UTC time, without the trailing Z
  • <prn>: Pseudo-random noise code of the GNSS satellite involved in the occultation
  • <level>: Product level, i.e. L1B
  • <product_type>: BND___
  • <proc_mode>: Internal field signifying processing mode; one of N(ear real-time), B(acklog), R(eprocessing) or V(alidation)
  • <disp_mode>: Internal field signifying disposition mode; one of O(perational), P(reoperational), C(ommissioning) or T(esting)

Note: the file name does not contain a quality indicator because only non-degraded bending angle profiles are converted into BUFR. There is also only one timestamp in the file name, signifying the (start) sensing time.

An example file name is


indicating that it contains bending angle data from the operational EUMETSAT processor used to process the Spire data. The occultation was observed by the satellite FM104 beginning at 15:14:21 UTC on 24 June 2021 and involved the GPS satellite G01 in the observation.

In the course of 2022 Q1, the data products will also be available on the WMO Global Telecommunications System (GTS).

Users wishing to receive these data on EUMETCast should register via our Earth Observation Portal (EOP).

For more information, contact our User Service Helpdesk.