Reports

Calculated columns

Some columns in Camelot are calculated from existing data, and some of those calculations are worthy of some explanation so that it’s clear what that column represents. Here are the most interesting ones:

Independent observations

A sighting is considered independent if two photos with the same sighting are taken at least some time threshold apart. If they are not, it is considered dependent. Whether they are considered dependent or independent effects the value of the data in this column.

Photos may be considered dependent if they are within the same Trap Station Session. That is to say, photos taken by two cameras of a Trap Station at the same time will be dependent if certain criteria about the two sightings are the same.

Below are some examples showing the various rules of the calculation (assume T=30 as the threshold). All rules assume sightings are within the same Trap Station Session; if that were not the case, they would always be independent.

Sighting Quantity Lifestage Sex T
Spp. 1 1 Adult Male 0
Spp. 2 1 Adult Male 5

These are independent as it’s a different species. The number of Independent Observations is 2.

Sighting Quantity Lifestage Sex T
Spp. 1 1 Adult Male 0
Spp. 1 1 Adult Male 40

These are independent as while it’s the same species, it is separated by T=40. The number of Independent Observations is 2.

Sighting Quantity Lifestage Sex T
Spp. 1 1 Adult Male 0
Spp. 1 2 Adult Male 5

These are dependent as it’s the same species, and up to 2 were sighted within the dependence window. The number of Independent Observations is 2.

Sighting Quantity Lifestage Sex T
Spp. 1 1 Adult Male 0
Spp. 1 1 Juvenile Male 5

These are independent as while it’s the same species, one is a juvenile and the other an adult. The number of Independent Observations is 2.

Sighting Quantity Lifestage Sex T
Spp. 1 1 Adult Male 0
Spp. 1 1 Unidentified Unidentified 5

These are dependent as while the lifestage and sex are not the same, unidentified values are inferred. The number of Independent Observations is 1.

Sighting Quantity Lifestage Sex T
Spp. 1 1 Unidentified Unidentified 0
Spp. 1 1 Adult Male 5
Spp. 1 1 Unidentified Female 10

Sighting 2 of Spp. 1 is dependent on sighting 1, due to inference on Lifestage and Sex. Sighting 3 is independent of both sighting 1 and sighting 2 due to that inference. The number of independent observations is 2.

Sighting fields, if configured for a survey, may also impact the independence of a sighting depending on its configuration.

The value of the threshold can be found in the Survey details menu.

Nocturnal (%)

This is simply the number of photos taken at night, divided by the number of photos. The interesting part is what is considered to be “at night”.

Night is determined as a time after sunset and before sunrise, given a particular set of GPS coordinates and on a particular day using the sunrise and sunset times as calculated by an algorithm published by the Nautical Almanac Office.

This algorithm does not attempt to account for atmospheric or geographical features, though will typically be accurate to within several minutes of the actual sunrise and sunset times.

Abundance Index

The Abundance Index is calculated using two pieces of data: the number of number of independent observations, and the number of nights of elapsed operation for a camera trap session, or for the combined elapsed time of all camera trap sessions (depending on the report).

The calculation of this value is then:

100 * Independent Observations / Nights