2. NGS Survey Proposal

If the intention is to use OP to submit a GNSS survey project to NGS, the user is required to submit a survey proposal via the NGS Survey Proposal form. The form can be reached by clicking on the “Surveys” tab on the NGS home page, and selecting “Survey Project Proposal Form” at the top of the drop-down list, as shown in Fig. 2.1. It is recommended to submit the proposal prior to data collection, in case any changes to the plan are recommended.

It is also recommended to contact your regional geodetic advisor to discuss the project requirements prior to submitting the proposal. The advisor can assist in the selection of the appropriate local control.

If the user is not interested in submitting the project to NGS, skip to Step 3, “Create your project in OP.”

NGS home page showing how to access NGS Survey Project Proposal Form

Fig. 2.1 NGS home page showing how to access NGS Survey Project Proposal Form

The form, as shown in Fig. 2.2, requests general information about the scope of your project, including title, state, whether the project is GNSS or leveling (the proposal form supports both kinds of projects), and approximately how many stations and over what period of time the survey is to be conducted.

Tip

If your project will contain GVX vectors, the “Includes RTK/RTN Data” box should be selected.

The NGS Survey Project Proposal Form

Fig. 2.2 The NGS Survey Project Proposal Form

The form requires the uploading of a survey network sketch, an observation schedule, and a photo of the type of user marks included in the project

Mark type is mainly reserved for photos or sketches identifying the kinds of new user marks set for the project. If no new user marks are being set, the photos or sketches can reflect the most typical kind of user mark included in the project. Examples of mark types are available from the [Help] link on the Survey Project Proposal page.

The Network sketch refers to the identification of the projects network baseline design, with baselines identified between the projects user marks and CORSs, as well as from base stations to rovers in RTK surveying. Examples are available by clicking on the [Sample] link on the Survey Project Proposal page, and are also explored in Section 11 of this manual. The sketch should also inherently reflect processing decisions for which marks are to be held constrained (in which dimensions), and which are to be unconstrained.

Tip

Consider the quality of the coordinates and heights of any mark used as a constraint in the project, including known uncertainties

The observation schedule lists the days, times of day, and the corresponding marks observed with GNSS, which can provide an idea of the eventual GNSS observation sessions involved. The schedule also specifies how many times each user mark will be observed as part of this project, or otherwise provides information regarding the procedures to be followed for creating the GNSS observation sessions in the project. Two samples are available from the links on the Survey Project Proposal page [Sample 1, Sample 2].

For static measurements, the only absolute requirement to successfully use OP for submitting a project to NGS is to have at least two, independent, ≥ 2-hour GNSS occupations on each user mark included in the project. However, NGS recommends following procedures outlined in the technical documents Zilkoski et al. (1997) and Zilkoski et al. (2008). Similarly, if conducting work for the Federal Aviation Administration (FAA), please consult the reference document AC-16.

For RTK measurements, the only absolute requirement to successfully use OP for submitting a project to NGS is at least three, independent, ≥ 5- minute occupations on mark(s) in the project. All three measurements must agree by 3 cm Horizontal and 5 cm Ellipsoid Height. They also must be separated by at least 3 hours, even if occupied on different days.

Caution

Static-only projects: NGS requires at a minimum two, independent, ≥ 2-hour GNSS occupations on each survey mark to be included in the project.

Caution

For RTK measurements, the only absolute requirement to successfully use OP for submitting a project to NGS is at least three, independent, ≥ 5- minute occupations on mark(s) in the project. All three measurements must agree by 3 cm Horizontal and 5 cm Ellipsoid Height. They also must be separated by at least 3 hours, even if occupied on different days.

Caution

There is a programmed limit of 99 project marks plus (including) CORS maximum per session

Caution

Disclaimer: this User Guide is a guide to using OPUS Projects for post-processing and adjusting campaign-style GNSS survey data. It is not a reference manual for policies and procedures relating to survey practices for conducting GNSS campaign-style surveys.

Once the form is submitted, the project information will be reviewed by NGS to ensure the project can meet the stated objectives (including desired accuracies). Once accepted, the project will be issued a unique Project Tracking ID.

Tip

Submit the proposal at least two weeks prior to the onset of the fieldwork. NGS will review the proposal and provide a NGS tracking ID if the project meets NGS standards, and may offer suggestions if/where appropriate.