7.4 Undertaking GNSS Project Field Work
Note
Before commencing any kind of field work using GNSS (or any other kind of equipment) it is necessary to ensure that you abide by any Workplace Health and Safety requirements of you organisation.
So, you’ve determined what accuracy you need, meaning you have your GNSS technique and equipment all selected, you’ve done your field reconnaissance and now you’re all kitted up and ready to go in the field – congratulations!
Reaching this part of any project can feel like a huge amount of work in its own right, and careful planning and consideration in the planning stage will usually pay off in terms of ensuring the field work component of data collection goes as smoothly as possible.
Field forms
In discussing metadata, position data and location intelligence, we discussed the idea of capturing various pieces of information about our GNSS survey to ensure that we can explain our work. We most often capture this information in a field form or booking sheet, which will provide a number of predefined fields that are required to be completed.
In GNSS surveying, static techniques still tend to use paper field forms to collect this information, as the amount of information and checks required to be undertaken are extensive. RTK will usually have a digital version of this process that is captured on the field controller.
Data capture techniques
While we might plan to use GNSS to collect information for our project, our best intentions are sometimes not enough to make GNSS work in certain places – like under trees!
To combat this, there are a number of surveying techniques we can use to still let us collect information about objects that can’t be collected directly by GNSS. We refer to these as alternative or advanced data capture techniques.
Finishing GNSS project field work
After capturing data in the field, the job is only half done!
The process of downloading data, post processing (if needed), scanning of paper documents and storing of files can be lengthy and involved. Organisations should have process to manage this part of any project, and should have consideration for:
- downloading processes
- file naming conventions and file formats
- storage of files in particular storage structures
- scanning resolutions of documents
- resolution of photos and scanning data to be stored
- deleting data from GNSS units
- provision of data to other organisations.
Checklists will assist these processes greatly, and will often be included as part of well-designed field forms.
Data download
To avoid any issues of finding out that no data has been collected or saved once you’re back in the office or home, you should ALWAYS check that there is the required data in the GNSS unit. If it is missing for some reason, you may be able to collect it again while you’re at the site.
It is also advisable that data be downloaded from the GNSS unit and a copy stored on an external device for redundancy. Accidentally running over your GNSS before you’ve downloaded it, but after you’ve finished collecting for the day is never going to be a fun experience!