Working with GPS

GNSS

global navigation satellite system, aka the broader world version of GPS (which is owned by the US)

• uses positioning, navigation, and timing (PNT)

Satellite connections

Operate in a medium orbit and need at least 4 satellite connections for GPS to work

Why is it useful for archaeologists

map and reconstruct sites, features, and landscapes in a digital format in order to visualize, interpret, and use spacial analysis on the data

GPS

US Global Positioning System that is one type of the GNSS

• world’s most utilized navigation system

GPS Space Segment

• consists of a constellation of satellites transmitting radio signal to handheld GPS devices

Latitude and Longitude

Latitude: how far North/South you are from the equator

• horizontal parallels that run East/West from 0 degrees at the equator to 90 at the poles

• Degrees North (+) and Degrees South (-)

Longitude: how far East/West you are from the prime meridian

• vertical meridians that run North/South from 0 degrees at the Prime Meridian to 180 East/West

• Degrees East (+) and Degrees West (-)

Key uses of GPS in archaeology

1. Grid mapping of a site: keeps track of where different features are found, where excavation units are placed, and how everything relates spatially

2. Creating a survey to facilitate data collection and recording

3. Environmental data collection: land cover impacts what things can be seen/what is preserved as well as spacial analysis

   1. weather at time of survey affects visibility/GPS accuracy

Survey 123

Form-centric type of ESRI software for collecting survey information via a questionnaire

• easy to use for non-GIS experts

• geotagging images

• blah blah we did this like its a survey with data from the field