Wave height and period can be measured with pressure gauges. Such 

 gauges can also report water-level variations. Vertical and horizontal 

 position of the gauges may be determined for support of dredging 

 operations with sufficient accuracy through DGPS survey. 



Investigation of DGPS 



Many of the inland coastal waters of Texas are nontidal according to 

 traditional NOS determinations. Therefore, a reference for navigational 

 purposes other than mllw must be used. Because interconnection of the 

 stations through conventional differential levels is not feasible, surveying 

 by vertical as well as horizontal DGPS procedures should be considered, 

 with due regard to verification of stated accuracy. 



Chapter 6 Conclusions and Recommendations 51 



