Gravity Gradiometer Survey Errors.
Abstract
Gradiometer system noise, sampling effects, downward continuation and limited data extent contribute to moving-base gravity gradiometer survey error. This report describes the individual effects of these error sources on a gravity gradiometer survey system currently under development. Special techniques are required to account for downward continuation and limited data extent effects which cannot be adequately modeled as measurement noise in a linear error estimation algorithm. The results reported herein indicate the survey performance improvement which could be realized if each error source were totally eliminated. The sensitivity of total survey error to small changes in the nominal value of each error source is also identified. System performance results are analyzed for several sets of airborne survey conditions. For a typical characterization of the earth's gravity field, limited data extent generally contributes about one-half of the total error variance associated with recovery of the gravity disturbance vector at the earth's surface; gradiometer system noise typically contributes about one-third. However, sampling effects are also very significant (and are controlled through the survey track spacing). The findings of this study indicate that a 5-km track spacing provides a reasonable tradeoff between survey cost and errors due to track spacing and that a moving-base gravity gradiometer system can recovery each component of the gravity disturbance vector with an rms accuracy better than 1.0 mGal. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1985
- Accession Number
- ADA165575
Entities
People
- Steven J. Brzezowski
Organizations
- TASC, Inc