Accession Number:

ADA196325

Title:

Estimation of Short-Wavelength Gravity on a Dense Grid Using Digital Terrain Elevation Data

Descriptive Note:

Scientific rept. no. 1, May 1986-May 1987

Corporate Author:

ANALYTIC SCIENCES CORP READING MA

Report Date:

1987-10-15

Pagination or Media Count:

40.0

Abstract:

The precise determination of the gravity field at or near the earths surface is required for compensating navigationguidance systems and for testing gravity gradiometers. With conventional gravimeters it is usually impractical to measure the gravity field over an extended area at very short wavelengthse.g., wavelengths less than 10 km. Since very short-wavelength gravitational perturbations at the surface are caused largely by near-surface mass variations in the local area, and since digital terrain elevation dataDTEDare available on dense gridse.g. three arc second spacingfor selected regions, the very short-wavelength components of gravity can be estimated without a gravity survey by using the DTED and the assumption of constant mass density. This report presents an approach to computing the short-wavelength, terrain-induced gravity field at a prescribed rms accuracy. For a relatively flat test area in Oklahoma, the rms effect of terrain elevation on the gravity field at mean elevation for wavelengths shorter than 10 km varies between 0.6 mgal and 2.2 mgal. The largest point value of the high-frequency terrain effect is 18.0 mgal. Keywords Geodesy Gravity Gravity gradiometry Gravity surveying Fast fourier transforms Geodetic surveys.

Subject Categories:

  • Geodesy
  • Navigation and Guidance

Distribution Statement:

APPROVED FOR PUBLIC RELEASE