Comparison of Potential Coefficient Determinations with 5 deg and 1 deg Anomalies,

The Earth's Gravity Field to Degree and Order 180 Using Seasat Altimeter Data, Terrestrial Gravity Data and Other Data,

“…This problem was examined by Colombo (1981) who carried out a theoretical and numerical analysis to predict the sampling error caused by the finite size of block being used. The results obtained by Colombo agreed quite well with the results obtained by Rapp (1980) in a purely numerical fashion.…”

“…This new data set was compared to our earlier merger with Geos-3 data (Rapp, 1980). For the 52972 common values wer found a root mean square difference of ±7.5 mglas, with a maximum difference of 127 mgals.…”

“…The results in Rapp (1980) also showed the problem of using 50 block averages in the combination solutions. To do this combination solutions, both 50 and 10 block data were used with the GEM 9 potential coefficients.…”

“…The computational effort in evaluating the matrix BZ P11 B was sufficiently great that an adjustment to only degree 12 was made. In Rapp (1980) simplifications were made in an attempt to make a more complete solution. To carry out this simplification we assume that the observation weights for the anomalies are assigned as follows:…”

“…We then examined procedures that might be of help in incorporating the higher degree coefficients without significantly changing our computer requirements. The results are described in Rapp (1980) where we examined combination solutions made with the rigorous procedures used in Rapp (1978) with a similar -1-procedure using certain assumptions that led to a considerably simplified solution.…”