On 02/13/2007 12:11 AM, Dave Perry wrote: > .... I can see how you generate a table that gives PA and C(s) for > layers with nonzero lapse rate. I assume you use equation (8) solved > for h to generate the table when lamda = 0.
Yes, equation 8, but I don't even need to solve for h. That's the funny thing about an interpolation table. To convert P(h) to h(P) all you need to do is transpose the ordinate <--> abscissa on each line of the table. > In this case, how do you > account for S = 29.92 being different from Pb? It seems to me that > Equation (8) will give us neither PA nor the Kollsman correction. I hope I never have to answer questions about that case. I assume that QNH values, considered as pressures, all lie at pressure altitudes *well* within the troposphere. So the Kollsman shift term can be computed by reference to layer 0 using equation 6, not 8. (I believe that if this assumption is not valid, a whole lot of things other than altimeters will be broken. :-) ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier. Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel