POST2 version 4.0D dated November 22, 2016

Version 4.0D of the Program to Optimize Simulated Trajectories II (POST2) is now available. This version has several upgrades and improvements based on feedback from users and assessment by developers. Over time, computational resource changes have resulted in adjustments needed in POST2 to better utilize current computer hardware capabilities and maintain compatibility with newer operating systems. The software was modified to support a 64-bit architecture as well as adjusted the structures to be only C-based and thus removing the reliance on aligning C and FORTRAN structures, often a significant issue in the previously released version.

Several other enhancements have been included in this release. All tables are automatically “cloned” when a new vehicle is created from another (previously these tables had to be input again to reset the independent variable to the new vehicle). A milestone can be read by POST2 on any platform independent of the platform’s binary byte ordering (Endianess) used to create it. Critical program variables, such as event criteria, event trigger values, event derivatives, print block output and virtually all mnemonic data in the program may now be integers. Vehicle attitude can be initialized using three new quaternion options (inertial to body, body to G-frame, and inertial to navigation frame). Additive table biases are now available to augment the previous table multiplier capability. Other changes are noted in the updated user’s manual.

Please refer to procedures to request POST2 for more information.