Table 1.

A comparison between various sensors and their applications.

Hardware Comparisons
Sensor Device and Manufacturer examples	Features	Fallbacks	Applications
Cameras
2D (RGB) — Lorax — eYenamic® 3D (RGBD) — Microsoft Kinect® — Intel Realsense® — eYegrow®	— Useful for fine positional and color variational data — High precision and lots of data — Remote sensing (non-invasive) — Fast readings (usually 15–60fps) — Individual or group can be analyzed	— Requires filtering to obtain useful information — Performance is dependent on lighting conditions — May require protective covers against   environmental elements	— Optical character recognition — Feature extraction — Motion detection — Topology extraction — Animal distribution and activity
Thermometers
Infrared Imaging (IR) — FLIR® — FLUKE® — TESTO 875®	— Useful for biological process observation and night vision — High performance in low visibility settings — Remote sensing (non-invasive) — Fast readings (usually 15–60fps)	— Expensive   (Mid hundreds to several thousands per unit) — Environmental factors affect readings	— Remote temperature sensing — Low light imaging — Physiological responses   (individualized and group)
Thermistors — Integrated in wearable sensors	— Useful for temperature fluctuations — Inexpensive	— Slow to sense changes — Not an off the shelf system	— Contact temperature sensing — Physiological responses
Microphones
— Soundtalks® — PCM Monitor®	— Useful for sound/frequency fluctuations —Immediate readings — Inexpensive	— Easily corrupted by noise	— Monitoring periodic physiological process (in pens and/or barns) — Auditory classification
Accelerometers
Exmples of WSN — Remote Insights® — Smartbow®	— Useful for motion tracking — Near instantaneous readings — Embedded into wearable sensors used in wireless sensor networks (WSN)	— Requires external processing to obtain displacement and velocity data —Information is relative   (not absolute) — Fragile   (can break with sow behavior)	— Motion detection/observation   (i.e., walking, nesting behavior) —Positional state tracking   (i.e., lying, standing)