Estimates total fleet activity by scaling sample-based trip statistics using boat registry data. Calculates sampling rates and confidence levels for the estimates.
Arguments
- monthly_stats
Data frame from `calculate_monthly_trip_stats()` containing: - district: District name - date_month: Month as date - sample_total_trips: Total trips from tracked boats - sample_boats_tracked: Number of tracked boats - avg_trip_duration_hrs: Average trip duration - avg_trips_per_boat_per_month: Average trips per boat
- boat_registry
Data frame with columns: - district: District name (must match monthly_stats) - total_boats: Total number of boats registered in district
Value
A data frame combining monthly statistics with fleet estimates: - district: District name - date_month: Month as date - sample_total_trips: Total trips from tracked boats - sample_boats_tracked: Number of tracked boats - avg_trip_duration_hrs: Average trip duration - avg_trips_per_boat_per_month: Average trips per boat - estimated_total_trips: Estimated trips for entire fleet - sampling_rate: Proportion of fleet tracked (0-1) - estimate_confidence: Confidence level ("High", "Medium", "Low")
Details
This function combines monthly trip statistics from GPS-tracked boats with boat registry data to estimate fleet-wide fishing activity. It calculates: - Estimated total trips if all boats were tracked - Sampling rate (tracked boats / total boats) - Confidence levels based on sampling coverage
Confidence levels are assigned as: - High: ≥30 - Medium: 10-29 - Low: <10
See also
* [calculate_monthly_trip_stats()] for generating input monthly statistics * [calculate_district_totals()] for combining with catch/revenue data
Examples
if (FALSE) { # \dontrun{
# First calculate monthly stats
monthly_stats <- calculate_monthly_trip_stats(trips_data)
# Then estimate fleet activity
fleet_estimates <- estimate_fleet_activity(monthly_stats, boat_registry)
# Check confidence levels
fleet_estimates |>
dplyr::count(estimate_confidence)
} # }