Strapdown airborne gravity measurement precision assessment method based on T1 Repeated Line Tl
Technical field:
The invention belongs to gravity measurement fields, are related to a kind of strapdown airborne gravity measurement precision assessment method, especially relate to
And be different from it is inside and outside meet precision, commented by the strapdown airborne gravity measurement precision that assessment models are established in T1 Repeated Line Tl flight
Estimate method.
Background technique:
Gravitation information has key effect in geodesic survey, geophysics and resource exploration.With other gravity measurement
Means are comparatively, airborne gravity measurement is not only able to satisfy each application field wants to gravity measurement accuracy and resolution ratio
It asks, while it has also taken into account this efficient advantage.The gravimeter used in airborne gravity measurement is generally divided into two kinds, Yi Zhongwei
Platform-type gravimeter, another kind are strapdown gravimeters.Compared with platform-type gravimeter, strapdown gravimeter utilizes mathematical measure
Rather than physical platform tracks geographic coordinate system, thus have small in size, low in energy consumption, structure simple and measurement result can be with
The advantage further excavated.
Accuracy evaluation is an important component of high-precision airborne gravity measurement, the assessment of airborne gravity measurement classics
Method is mainly precision of inner coincidence appraisal procedure and precision of exterior coincidence appraisal procedure.In classical appraisal procedure, inside meet essence
Degree generally requires carrier and carries out repeat sequence or cross spider flight to carry out the evaluation work of precision, increases aviation weight in this way
The cost of power measurement;Precision of exterior coincidence needs the reference to gravitational provided by ground gravity upward continuation or other reliable gravimeters
Information carries out accuracy evaluation, and usually no priori gravitation information when carrying out aerial survey.Documents (Guo Zhi
It is macro, the airborne gravity T1 Repeated Line Tl test data quality evaluating method such as Xiong Shengqing, Zhou Jianxin research Chinese Journal of Geophysics, 2008,
51 (5): airborne gravity T1 Repeated Line Tl test data mean square deviation accuracy computation method 1538~1543) is disclosed.According to documents
The inside and outside calculated result for meeting precision of T1 Repeated Line Tl test data mean square deviation more can objectively assess the dynamic measurement essence of instrument
Index and work shape are spent, but it is still based on classical appraisal procedure, needs additionally to be flown or extraneous reference information.
Classical appraisal procedure is more prone to the performance estimating method of airborne gravitormeter itself, not by additional flight with
And in the case where extraneous reference information, the precision of single survey line can not be assessed effectively, airborne gravity measurement is unfavorable for
Quality control.Therefore, it realizes that one kind meets precision different from inside and outside, single can be assessed based on strapdown airborne gravitormeter
The strapdown airborne gravity measurement precision assessment method of survey line precision has very high application value and realistic meaning.
Summary of the invention:
The present invention aiming at the problem that classical airborne gravity evaluation method cannot efficiently assess strapdown gravity measurement precision, from
Strapdown gravimeter error characteristics and system perspective are set out, and a kind of strapdown airborne gravity measurement based on T1 Repeated Line Tl is proposed
Precision assessment method.
Main technical solution is as follows:
Strapdown airborne gravity measurement precision assessment method based on T1 Repeated Line Tl, comprising the following steps:
Step 1, by trajectory planning make in this measurement task carrier survey back and forth the air route between area and airport at
For T1 Repeated Line Tl or strapdown early period airborne gravitormeter T1 Repeated Line Tl flying quality is collected, and calculates these T1 Repeated Line Tls in-flight by victory
The day on every survey line that connection formula airborne gravitormeter measurement obtains is to specific force standard deviation, horizontal specific force standard deviation, pitch angle standard
The precision of inner coincidence of difference, roll mean angular deviation and gravity anomaly result, wherein horizontal specific force is obtained by formula (1):
Wherein, fhRepresent horizontal specific force, fnRepresent north orientation specific force, feRepresent east orientation specific force;
Step 2 returns to analysis using polynary, establishes day to specific force standard deviation, horizontal specific force standard deviation, pitch angle standard
With the relational model between precision of inner coincidence, this relational model is precision for difference and four key indexes of roll mean angular deviation
Assessment models;
Step 3 extracts aforementioned four key index, and utilize after terminating certain airborne gravity measurement from new survey line
Accuracy evaluation model obtained in step 2 estimates the measurement accuracy of new survey line, to evaluate the measurement quality of this bar survey line;
Step 4, if the T1 Repeated Line Tl during model foundation is obtained by trajectory planning, with air route T1 Repeated Line Tl
The accumulation of data, accuracy evaluation model obtained in further amendment step two is to guarantee model accuracy.
Compared with classical way, the invention has the following advantages that
1) method in the present invention does not need additional flight survey line, passes through trajectory planning or T1 Repeated Line Tl data early period
It realizes accuracy evaluation, reduces the cost of airborne gravity measurement accuracy evaluation;
2) meaning that T1 Repeated Line Tl flies in airborne gravity measurement is extended.T1 Repeated Line Tl flight not only can detecte gravimeter work
Make state and precision, can be also used for establishing measurement accuracy of the accuracy evaluation model to assess other sorties.
3) accuracy evaluation model has versatility, can be used for different measurement sorties after foundation and surveys area.
4) present invention highlights strapdown gravimeter compared to the advantage in terms of platform-type gravimeter data mining.
Detailed description of the invention:
T1 Repeated Line Tl path used and coverage of survey area when Fig. 1 is model foundation;
Fig. 2 is the residual error and 95% confidence interval during accuracy evaluation model foundation;
Fig. 3 is the flight path that two T1 Repeated Line Tls test sortie;
Fig. 4 is error of the estimated accuracy compared with precision of inner coincidence;
Fig. 5 is method flow diagram.
Specific embodiment:
It is tested with reference to the accompanying drawing with certain practical airborne gravity measurement, the precision assessment method in the present invention is done into one
Step elaborates, the organizing and implementing situation of experiment such as table 1.
Table 1
Step 1 makes carrier survey the boat between area and airport back and forth in the secondary measurement task by trajectory planning
Road becomes T1 Repeated Line Tl, and T1 Repeated Line Tl path and survey area are as shown in Figure 1, strapdown airborne gravitormeter weight early period can also be collected directly
Multiple line flying quality.The influence of the factors such as removal air route conflict obtains 22 experiment lines from 13 Sorties altogether, calculates this
The pitching mean angular deviation on every survey line that is obtained in a little T1 Repeated Line Tls by strapdown airborne gravitormeter measurement, roll mean angular deviation,
Horizontal specific force standard deviation, day are to specific force standard deviation and precision of inner coincidence, and the results are shown in Table 2.
Table 2
Step 2 returns to analysis using polynary, establishes day to specific force standard deviation, horizontal specific force standard deviation, pitch angle standard
With the relational model between precision of inner coincidence, this relational model is precision for difference and four key indexes of roll mean angular deviation
Assessment models.Analysis is returned to using polynary, the accuracy evaluation model such as formula (2) obtained by 2 information of table, accuracy evaluation model is built
Residual error and 95% confidence interval such as Fig. 2 during vertical
Wherein,For roll angle,For pitch angle, fhFor horizontal specific force, fnIt is day to specific force.
Step 3 extracts aforementioned four key index, and utilize after terminating certain airborne gravity measurement from new survey line
Relational model obtained in step 2 estimates measurement quality of the measurement accuracy of new survey line to evaluate this bar survey line.Using in addition
Accuracy evaluation model obtained in the flying quality verification step two of two T1 Repeated Line Tl sorties, the flight of the two T1 Repeated Line Tl sorties
Track such as Fig. 3.Pitching mean angular deviation, roll mean angular deviation, horizontal specific force standard deviation, day in the two T1 Repeated Line Tl sorties to than
Power standard deviation and precision of inner coincidence are as shown in table 3.The estimated accuracy obtained using formula (2) is compared with precision of inner coincidence, most
Big error is 0.56mGal, and the standard deviation of error is 0.22mGal.Error of the estimated accuracy compared with precision of inner coincidence such as Fig. 4 institute
Show.The result shows that accuracy evaluation model can preferably evaluate the precision of airborne gravity measurement.
Table 3
Step 4, if the T1 Repeated Line Tl during model foundation is obtained by trajectory planning, then establishing model
Later, with the further accumulation of air route T1 Repeated Line Tl data, the available extension of the data of table 2, and then the relationship in step 2
Model is further corrected, and ensures that the precision in entire measurement task of model in this way, specifically such as institute in step 2
Show.
The practicability of accuracy evaluation model, the flow chart of method such as Fig. 5 are demonstrated based on certain airborne gravity measurement task
It is shown.The result shows that Evaluation accuracy, compared with precision of inner coincidence, the standard deviation of worst error 0.56mGal, error are
0.22mGal, the two have preferable consistency.Wherein, the Evaluation accuracy obtained based on accuracy evaluation model does not need special heavy
Multiple line and Evaluation accuracy is more stringent compared with precision of inner coincidence.
The above is only the preferred embodiment of the present invention, protection scope of the present invention is not limited merely to above-described embodiment,
All technical solutions belonged under thinking of the present invention all belong to the scope of protection of the present invention.It should be pointed out that for the art
For those of ordinary skill, several improvements and modifications without departing from the principles of the present invention should be regarded as protection of the invention
Range.