Propeller Correction Network (Australia)—Continuing Support for GDA94

The Propeller Corrections Network integrates base stations from all over the world and takes the hard work out of sourcing and uploading a RINEX file to correct your AeroPoint survey with satellite observations from a nearby base station.

When processing data using the Propeller Corrections Network, Propeller looks for a base station close to your AeroPoint survey and downloads the appropriate RINEX file covering the survey duration. 

Australia’s old national datum, GDA94, has been deprecated. GDA2020 has now been adopted by many of Australia's base station service providers. When surveying an area that no longer provides GDA94 corrections, we will use a transformation from GDA2020 to GDA94 to continue supporting projects utilizing GDA94.

AeroPoint dashboard

In the AeroPoint dashboard, when processing a survey and there’s a possibility of datum transformation, the  following message will appear:

When viewing and/or downloading coordinates for a survey processed based on either GDA94 or GDA2020 system, the user should be able to select any coordinate system based on either GDA94 or GDA2020 system.

Propeller Uploader

The output coordinate reference system (CRS) will now default to match the site’s CRS.

Frequently Asked Questions:

1. Will the datum transformation be applied to uploaded high-accuracy geotagged photo datasets?
No. The datum transformation will only be applied to AeroPoint surveys processed using the Propeller Correction Network method.

For more details on uploading high-accuracy geotagged photo datasets that have been geotagged using an RTK or PPK solution other than Propeller PPK, please visit this page.

2. Will the new surveys’ transformed outputs be different when compared to my previous surveys?
Since GDA94 base station coordinates are old and not up to date, when a survey processed using the base station is compared with surveys processed using the new GDA2020 coordinates transformed to GDA94, there could be differences that are usually minimal and unnoticeable. In cases where the slight differences are noticeable, Geospatial Specialists will investigate, ensure that it’s attributed to the datum transformation, and relay said information when the survey is released.

3. Can I resubmit old surveys for them to align with the new surveys?
Yes, but please note that base station correction data may no longer be available from Propeller Correction Network third-party providers in the area.

4. Are all base station providers in Australia using GDA2020?
Some remaining base station networks only provide coordinates in GDA94, particularly in Western Australia. In this case, if a site is set up in GDA2020, but the base station correction data is from the said providers, we perform a datum transformation from GDA94 to GDA2020.

5. In which datum will my outputs be based?
The geographic coordinate system presented in the AeroPoint dashboard is always the Coordinate System (CS) in which the AeroPoints are processed, i.e., the CS of the base station used. But the Output CS that are initially displayed will depend either on:

  • the site's CS (if there is a site linked to the AeroPointsurvey)

  • the selected datum before the AeroPoint processing (if there is no site linked to the AeroPointsurvey)

6. Can I opt not to use datum transformation and stick to the GDA94 stale coordinates (to avoid my new datasets from not aligning with my previous datasets)?
When the survey is in an area where GDA94 corrections are no longer provided, the only way to process datasets utilizing GDA94 is through the transformation from GDA2020 to GDA94.

However, users may opt for other AeroPoint™ survey processing methods such as Global Survey Benchmark or RINEX upload, if (a) it's preferred to use GDA94 as the datum for the AeroPoint™ survey to be processed in, and (b) the necessary data/information is available and can be provided.

I still can't do it!

We wrote these articles to equip you with everything you need to get the job done on your own, but we understand that sometimes this isn't sufficient.

If you're stuck, you can connect with our support team by clicking the support button on the top right corner of your user portal.