System and method for surveying a non-stationary platform subject to thermal expansion
A method includes obtaining an initial survey of multiple receivers located on a dynamic platform. The method also includes obtaining sensor readings from the multiple receivers. The method further includes validating, using a differential calculator, the initial survey by (i) selecting a reference receiver and a target receiver from among the multiple receivers and (ii) calculating, based on the sensor readings and baselines between the reference receiver and one or more remaining receivers, a platform attitude, platform thermal expansion state, and survey error values corresponding to the target receiver. The method also includes, starting from a validated survey, adding a new receiver to the initial survey by (i) determining a baseline between the reference receiver and the new receiver and (ii) associating the baseline to a coordinate frame of the initial survey.
1. A method comprising:
obtaining an initial survey of multiple receivers located on a dynamic platform;
obtaining sensor readings from the multiple receivers; and
validating, using a differential calculator, the initial survey by:
selecting a reference receiver and a target receiver from among the multiple receivers; and
calculating, based on the sensor readings and baselines between the reference receiver and one or more remaining receivers, a platform attitude, platform thermal expansion state, and survey error values corresponding to the target receiver.
2. The method of claim 1 , further comprising:
in response to the survey error values exceeding threshold values, correcting a coordinate value of the target receiver based on the survey error values.
3. The method of claim 1 , wherein calculating the platform attitude and the survey error values comprises performing least-squares ambiguity decorrelation adjustment (LAMBDA) calculations.
4. The method of claim 1 wherein calculating the platform attitude, the platform thermal expansion state, and the survey error values comprises simultaneously estimating (i) the platform attitude, (ii) the platform thermal expansion state, (iii) the survey error values, and (iv) a carrier phase measurement ambiguity.
5. The method of claim 1 , further comprising:
iteratively selecting the reference and target receivers and calculating the platform attitude, the platform thermal expansion state, and the survey error values for each receiver among the multiple receivers.
6. The method of claim 1 , further comprising:
after validating the initial survey, adding a new receiver to the initial survey by (i) determining a baseline between the reference receiver and the new receiver and (ii) associating the baseline to a coordinate frame of the initial survey.
7. The method of claim 1 , wherein the multiple receivers comprise global navigation satellite system (GNSS) receivers.
8. A non-transitory computer readable medium containing instructions that when executed cause at least one processor to:
obtain an initial survey of multiple receivers located on a dynamic platform;
obtain sensor readings from the multiple receivers; and
validate, using a differential calculator, the initial survey;
wherein the instructions that when executed cause the at least one processor to validate the initial survey comprise instructions that when executed cause the at least one processor to:
select a reference receiver and a target receiver from among the multiple receivers; and
calculate, based on the sensor readings and baselines between the reference receiver and one or more remaining receivers, a platform attitude, platform thermal expansion state, and survey error values corresponding to the target receiver.
9. The non-transitory computer readable medium of claim 8 , further containing instructions that when executed cause the at least one processor to:
in response to the survey error values exceeding threshold values, correct a coordinate value of the target receiver based on the survey error values.
10. The non-transitory computer readable medium of claim 8 , wherein the instructions that when executed cause the at least one processor to calculate the platform attitude, the platform thermal expansion state, and the survey error values comprise:
instructions that when executed cause the at least one processor to perform least-squares ambiguity decorrelation adjustment (LAMBDA) calculations.
11. The non-transitory computer readable medium of claim 8 , wherein the instructions that when executed cause the at least one processor to calculate the platform attitude, the platform thermal expansion state, and the survey error values comprise:
instructions that when executed cause the at least one processor to calculate the platform attitude, the platform thermal expansion state, and the survey error values by simultaneously estimating (i) the platform attitude, (ii) the platform thermal expansion state, (iii) the survey error values, and (iv) a carrier phase measurement ambiguity.
12. The non-transitory computer readable medium of claim 8 , wherein the instructions that when executed cause the at least one processor to calculate the platform attitude, the platform thermal expansion state, and the survey error values comprise:
instructions that when executed cause the at least one processor to iteratively select the reference and target receivers and calculate the platform attitude, the platform thermal expansion state, and the survey error values for each receiver among the multiple receivers.
13. The non-transitory computer readable medium of claim 8 , further containing instructions that when executed cause the at least one processor to:
after validating the initial survey, add a new receiver to the initial survey by (i) determining a baseline between the reference receiver and the new receiver and (ii) associating the baseline to a coordinate frame of the initial survey.
14. The non-transitory computer readable medium of claim 8 , wherein the multiple receivers comprise global navigation satellite system (GNSS) receivers.
15. A device comprising:
at least one processing device configured to:
obtain an initial survey of multiple receivers located on a dynamic platform;
obtain sensor readings from the multiple receivers; and
validate, using a differential calculator, the initial survey;
wherein, to validate the initial survey, the at least one processing device is configured to:
select a reference receiver and a target receiver from among the multiple receivers; and
calculate, based on the sensor readings and baselines between the reference receiver and one or more remaining receivers, a platform attitude, platform thermal expansion state, and survey error values corresponding to the target receiver.
16. The device of claim 15 , wherein the at least one processing device is further configured, in response to the survey error values exceeding threshold values, to correct a coordinate value of the target receiver based on the survey error values.
17. The device of claim 15 , wherein, to calculate the platform attitude, the platform thermal expansion state, and the survey error values, the at least one processing device is configured to perform least-squares ambiguity decorrelation adjustment (LAMBDA) calculations.
18. The device of claim 15 , wherein the at least one processing device is further configured to iteratively select the reference and target receivers and calculate the platform attitude, the platform thermal expansion state, and the survey error values for each receiver among the multiple receivers.
19. The device of claim 15 , wherein the at least one processing device is further configured, after validating the initial survey, to add a new receiver to the initial survey by (i) determining a baseline between the reference receiver and the new receiver and (ii) associating the baseline to a coordinate frame of the initial survey.
20. The device of claim 15 , wherein the multiple receivers comprise global navigation satellite system (GNSS) receivers.