12.2. Recommended Network Adjustment Sequence Without NGS Project Tracking ID

There are any number of reasons why a user may opt not to submit a campaign-style GNSS project to NGS. A project may lie outside the United States and its territories; a project may, for scientific reasons, prefer to be tied to the ITRF; alignment to the NSRS reference frame is not wanted; alignment to a local network/datum may be required, etc. Furthermore, GPSCOM attempts to resolve a larger number of error sources than ADJUST. To support the widest possible client base, OP allows users to remain entirely in GPSCOM. Since the project will not be submitted to NGS, there is no need to have users follow the same sequential processing steps as presented in Section 12.1. However, OP will suggest an initial minimally constrained adjustment which is exactly the same as the Preliminary Adjustment shown in Figure 12.1. This will enable the user to evaluate how all sessions fit together without any confounding influence of multiple constraints which may end up being inconsistent. Refer to 12.1 for additional guidance on setting up and analyzing the results from this adjustment. After verifying the correctness of all sessions and observations, the user can then proceed to conduct another (or more) adjustment(s), if needed, with additional constraints. If a user wishes to align the network to a vertical datum in the NSRS, NGS recommends using a project tracking ID (or using the default value of “0000”) and following the sequential adjustments presented in Section 12.1. This will allow running the vertical free and vertical constrained adjustments.

---