A method for processing an alert message generated and transmitted by a method for improving the continuity in a dual frequency satellite navigation system, wherein the method for improving the continuity in the dual frequency satellite navigation system comprises following steps: - observing the ionosphere by measurements in the two or more frequency bands, and - transmitting the alert message informing utilization systems about a change of the ionosphere, when at least one measurement results in a change of the ionosphere deviating from one or more predetermined conditions, wherein the method for processing the alert message comprises following steps: - receiving the alert message transmitted with the method for improving the continuity in the dual frequency satellite navigation system, - determining the information included in the alert message about a change of the ionosphere, and - calculating the influence on a position determination due to the change of the ionosphere, characterized in that the method for processing the alert message is performed by a receiver for satellite signals of a dual frequency satellite navigation system, wherein first the receiver receives two measurement signals on two different frequencies and then the receiver loses one of the measurement signals such that only one of the two measurement signals is available, and the receiver uses the ionospheric propagation delay of the measurement signal last determined from the two frequency measurement, wherein the method for processing the alert message further comprises the following step: deciding whether the last determined ionospheric propagation delay of the measurement signal can be used for a compensation of the influence on the ionosphere due to the change of the ionosphere received in the alert message. - observing the ionosphere by measurements in the two or more frequency bands, and - transmitting the alert message informing utilization systems about a change of the ionosphere, when at least one measurement results in a change of the ionosphere deviating from one or more predetermined conditions, wherein the method for processing the alert message comprises following steps: - receiving the alert message transmitted with the method for improving the continuity in the dual frequency satellite navigation system, - determining the information included in the alert message about a change of the ionosphere, and - calculating the influence on a position determination due to the change of the ionosphere, characterized in that the method for processing the alert message is performed by a receiver for satellite signals of a dual frequency satellite navigation system, wherein first the receiver receives two measurement signals on two different frequencies and then the receiver loses one of the measurement signals such that only one of the two measurement signals is available, and the receiver uses the ionospheric propagation delay of the measurement signal last determined from the two frequency measurement, wherein the method for processing the alert message further comprises the following step: deciding whether the last determined ionospheric propagation delay of the measurement signal can be used for a compensation of the influence on the ionosphere due to the change of the ionosphere received in the alert message. deciding whether the last determined ionospheric propagation delay of the measurement signal can be used for a compensation of the influence on the ionosphere due to the change of the ionosphere received in the alert message.