What if your coordinates are in degrees minutes seconds?#

The Atlas of Living Australia, and many other atlases, will report occurrence records as degrees latitude and degrees longitude in the Coordinate Reference System WGS84. However, we acknowledge there are many formats to measure latitude and longitude. Here, we will take you through how to convert your coordinates from these other common systems of measurement into degrees latitude and longitude.

Thankfully, there is a great package for this called lat_lon_parser. To install this package, type the following command into a terminal:

pip install lat-lon-parser

Here, we will show you a few examples of converting different formats to degrees latitude and degrees longitude.

Converting Degrees Minutes Seconds#

Let’s say you have the latitude coordinate 35° 50' 11" and the longitude coordinate 138° 01' 26". To convert them using the lat-lon-parser, type

>>> from lat_lon_parser import parse
>>> parse("35\° 50' 11\"")
>>> parse("138\° 01\' 26\"")

35.83638888888889
138.0238888888889

The package will expect the text in order of degrees minutes seconds, with the appropriate signs and the numbers having a separator. The back slashes tell Python that those are special characters, rather than the beginnings and ends of strings or other things

If you want to loop over your data frame containing these types of numbers, you can run something like the following example:

>>> from lat_lon_parser import parse
>>> import pandas as pd
>>> occ = pd.DataFrame(
...     {
...         'decimalLatitude': ["35\° 50' 11\"", "45\° 51' 13\"", "30\° 20' 10\""],
...         'decimalLongitude': ["138\° 01\' 26\"", "139\° 11\' 16\"", "128\° 05\' 29\""]
...     }
... )
>>> for i, row in occ.iterrows():
...     occ.at[i, 'decimalLatitude'] = round(parse(row['decimalLatitude']),2)
...     occ.at[i, 'decimalLongitude'] = round(parse(row['decimalLongitude']),2)
>>> occ

  decimalLatitude decimalLongitude
0           35.84           138.02
1           45.85           139.19
2           30.34           128.09

Here, we have converted a pandas DataFrame containing coordinates in degrees minutes seconds to decimal degrees, and have rounded the answer to two decimal places. This is to ensure good rounding practices, as well as fewer digits in the converted number.