Systems and methods for receiving information at rover receivers in navigation satellite systems
A navigation satellite system, one or more NSS reference station is set out for providing information to one or more rover receivers. The NSS reference station comprises a processing unit configured to determine one or more first range intervals representing first ambiguity windows based on estimated atmospheric effects, and determine one or more second range intervals representing a second ambiguity window smaller than each of the first ambiguity windows based on uncertainties of range measurements within a predetermined previous period. The NSS reference station further comprises a transmission unit configured to transmit, to the NSS rover receivers, first messages each comprising a modulo a first ambiguity window, and transmission of two first messages, to range measurement transmit between the NSS rover receiver, a plurality of second messages, each second message comprising a range measurement modulo one of the second ambiguity windows.
1. A navigation satellite system, NSS, rover receiver for receiving information from a NSS reference station, the NSS rover receiver comprising:
a reception unit configured to:
receive, from the NSS reference station, first messages each comprising a respective first range measurement modulo a first range interval, wherein a time interval between transmission of each first message is equal to or less than a time duration of a predetermined previous time period; and
receive between reception of two first messages, from the NSS reference station, a plurality of second messages, each second message comprising a size of a second range interval, the time duration of the predetermined previous time period, and a respective second range measurement modulo the second range interval, the second range interval being smaller than the first range interval; and
a processing unit configured to reconstruct the second range measurement associated with each second message.
2. The NSS rover receiver according to claim 1 , wherein the first range interval is based on estimated atmospheric effects on the first range measurements determined from carrier phase observations.
3. The NSS rover receiver according to claim 1 , wherein the second range interval is based on uncertainties of range measurements within the predetermined previous time period, the uncertainties of the range measurements being differences between first range measurements determined from carrier phase observations and second range measurements determined from satellite orbit parameters and a location of the NSS reference station.
4. The NSS rover receiver according to claim 1 , wherein a time interval between reception of the two first messages is based on at least one of:
data link reliability conditions between the NSS rover receiver and the NSS reference station; and
a duration of a maximum acceptable interruption between the NSS rover receiver and the NSS reference station.
5. A system comprising:
a NSS rover receiver according to claim 1 .
6. Method for receiving information from a navigation satellite system, NSS, reference station at one or more NSS rover receivers, wherein the method comprises the steps of:
receiving, at the NSS rover receiver, first messages each comprising a respective first range measurement modulo a first range interval, wherein a time interval between transmission of each first message is equal to or less than a time duration of a predetermined previous time period;
receiving, at the NSS rover receiver, between reception of two first messages, from the GNSS reference station, a plurality of second messages, each second message comprising a size of a second range interval, the time duration of the predetermined previous time period, and a respective second range measurement modulo the second range interval, the second range interval being smaller than the first range interval; and
reconstructing the second range measurement associated with each of the plurality of second messages.
7. The method according to claim 6 , wherein the first range interval is based on estimated atmospheric effects on the first range measurements determined from carrier phase observations.
8. The method according to claim 6 , wherein the second range interval is based on uncertainties of range measurements within the predetermined previous time period, the uncertainties of the range measurements being differences between first range measurements determined from carrier phase observations and second range measurements determined from satellite orbit parameters and a location of the NSS reference station.
9. The method according to claim 6 , wherein a time interval between reception of the two first messages is based on at least one of:
data link reliability conditions between the NSS rover receiver and the NSS reference station; and
a duration of a maximum acceptable interruption between the NSS rover receiver and the NSS reference station.
10. The method according to claim 6 , wherein the size of the second range interval for a second message is larger than the size of the second range interval for a preceding second message.
11. A nontransitory computer readable medium comprising a computer program loadable onto a processing unit of a navigation satellite system, NSS, rover receiver comprising code for executing a method comprises the steps of:
receiving, at the NSS rover receiver, first messages each comprising a respective first range measurement modulo a first range interval, wherein a time interval between transmission of each first message is equal to or less than a time duration of a predetermined previous time period;
receiving, at the NSS rover receiver, between reception of two first messages, from the GNSS reference station, a plurality of second messages, each second message comprising a size of a second range interval, the time duration of the predetermined previous time period, and a respective second range measurement modulo the second range interval, the second range interval being smaller than the first range interval; and
reconstructing the second range measurement associated with each of the plurality of second messages.
12. A navigation satellite system, NSS, rover receiver for receiving information from a NSS reference station, the NSS rover receiver comprising:
a reception unit configured to:
receive, from the NSS reference station, first messages each comprising a respective first range measurement modulo a first range interval, wherein the first range interval is based on estimated atmospheric effects on the first range measurements determined from carrier phase observations, and a time interval between transmission of each first message is equal to or less than a time duration of a predetermined previous time period; and
receive between reception of two first messages, from the NSS reference station, a plurality of second messages, each second message comprising a size of a second range interval, the time duration of the predetermined previous time period, and a respective second range measurement modulo the second range interval, the second range interval being smaller than the first range interval, wherein the second range interval is based on uncertainties of range measurements within the predetermined previous time period, the uncertainties of the range measurements being differences between first range measurements determined from carrier phase observations and second range measurements determined from satellite orbit parameters and a location of the NSS reference station; and
a processing unit configured to reconstruct the second range measurement associated with each second message.
13. The NSS rover receiver according to claim 12 , wherein a time interval between reception of the two first messages is based on at least one of:
data link reliability conditions between the NSS rover receiver and the NSS reference station; and
a duration of a maximum acceptable interruption between the NSS rover receiver and the NSS reference station.