New Survey Project Form - Establish Permanent Geodetic Control (PACs and SACs)

When creating a survey project, you can choose to tie your survey into the National Geodetic Survey (NGS) markers. This new option gives Airport Sponsors additional flexibility in choosing the exact type of airport project to create.

The project workflow is a standard workflow, but simpler. The only requirement for the surveyor to submit is a Geodetic Control Plan for review and approval. No other plans are required for this project type.

About PACS and SACS

PACS and SACS are control stations established near an airport and tied directly to the National Spatial Reference System (NSRS).

  • PACS stands for Primary Airport Control Station
  • SACS stands for Secondary Airport Control Station

The control consists of permanent marks with precisely determined latitudes, longitudes, and elevations. PACS and SACS are designated by NGS to meet specific siting, construction, and accuracy requirements.

Typical NGS Permanent Mark, a Bronze Disk

Typical NGS Permanent Mark, a Bronze Disk

You must use these survey marks for aeronautical and engineering projects related to runway or taxiway construction, navigational aid siting, obstruction clearing, road building, and other airport improvement activities.

  • For horizontal datum, use North American Datum of (NAD) 83 (YYYY), where YYYY is the year of the most recent observations. Note: The year of observations is on the NGS datasheet next to the latitude and longitude.
  • For vertical reference, use North American Vertical Datum (NAVD) 88. Learn more at
  • New Survey Project Form with Geodetic (PACS/SACS) Control

    On the New Survey Project Form, the option is Survey Work - Establish permanent geodetic controls (PACS/SACS). This option allows the surveyor to submit a Geodetic Control Plan, and no other plans are required.

    Create PACs/SACs Data Project

    1. Click Create New Survey Project link from the Projects menu bar, or from the Survey Projects pane on the Airports GIS Home page.
    1. In Step 1, select your Airport from the drop-down list. Check New Airport Survey Project. Click "Next" button for Step 2, Airport Category and Level of Verification.
    1. In Step 2, select your Airport Category. The form expands with additional information on project requirements and verification options.
    1. In Step 3, check the Survey Work - Establish Geodetic Control (PACS/SACS) as the Purpose of Survey. Optionally, enter the API Grant Number. Click "Next" button for Step 4, Confirmation.
    1. In Step 4, you verify and confirm your project set up and requirements. Click Back to correct any previous choices. Finally, click Submit to complete the process.

    Your airport’s Project Summary page displays. It cites the Purpose as establishing permanent geodetic control. Proceed as you would with any other survey project, bearing in mind the surveyor will need to submit a Geodetic Control Plan for review and approval.

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