cannot pass UTM zone to as.telemetry

[Jasja Dekker]

After searching through the conversations, I could not find a solution to my issue: I cannot seem to get my data into the right projection.

My data is a set consisting of locations from different sensors, so I could not work with nicely formatted movebank exports.

So I've converted my data from lat-long to UTM zone 31 using st_transform(data, 32631), extracted x and y and reformatted these with the subject and timestamp into a dataframe. 

Then I tried several ways to pass the projection, including adding the zone as a column called UTM.zone = "31" and the following:

myTelemetry <- ctmm::as.telemetry(df)

myTelemetry <- ctmm::as.telemetry(df, projection = CRS("+init=epsg:32631"))

 myTelemetry <- ctmm::as.telemetry(df,
                                   projection = sf::st_crs(32631)$proj4string)
 

myTelemetry <- ctmm::as.telemetry(df,
                                   projection = sf::st_crs(32631)$proj4string,
                                   UTM.zone= "+proj=utm +zone=31 +north +datum=WGS84 +units=m +no_defs")

But I keep getting "UTM zone missing; assuming UTM zone="1N"." message and when I ask for a summary(myTelemetry) it shows longitudes of -174 and lattitudes of ~53.  although plotting the data does look like it does in the original lat-long dataset.

This is driving me nuts. Is there a solution I am missing? Should I try reading in the WGS84 data?

Advice would be much appreciated! 

All the best,

Jasja

[Christen Fleming]

Hi Jasja,

Is this the development version of the package from GitHub and are all of your other packages up to date? PROJ standards change periodically, which makes older package become incompatible.

x,y,UTM.zone columns should work for importing, as should long,lat.

After importing, you can just do projection(myTelemetry) <-  32631.

If that doesn't work, you can send me an example data frame and I can take a look at it.

Best,

Chris