I'm also working on detection function with multiple year. I'm trying to do a single detection function with all my data across the years.
I fixed the problem of unconsistency by setting 1 value of area per year. I don't have the error message anymore.
But, when I compute the ds function, I have 0 for all my density and abundance estimators and I can't find why.
I tried to calculate them with dht function, and I discovered this error :
"Must specify obs.table because Sample.Label and/or Region.Label fields not contained in data"
This is very strange, since they are in my data, and are found when I take the years individually.
Thank you by advance for your response,