Tactics and Vectors 98/99
                            Home ] Up ] How to Record Date And Time Of Observation ] How to Identify Common Species of Migratory Butterflies ] Flight Behavior I ] Flight Behavior II ] Flight Behavior III ] Flight Behavior IV ] Flight Behavior V ] Weather Data ] Weather Data ] [ How To Determine Coordinates of the Exact Location of your Field SiteWhere to find Altitude ] Properties of Magnetic Field at Field Site How to Determine Magnetic Declination and Magnetic Inclination ]


Table of  Contents

Great Circle Hypotheis  

Magnetoclinic Hypothesis

Magnetic-Latitude Hypothesis

Compass Bearings Hypothesis

Suns' Azimuth Hypothesis

Expansion-Contraction Hypothesis

Always Advance Hypothesis

Never Go Back Hypothesis



How To Determine the Co-ordinates of the Exact Location of your Field Site


Where to find Altitude, Latitude, and Longitude

Altitude, Latitude, and Longitude of the field site need to be recorded only once and can be added to the data forms at any time. Coordinates for Latitude and Longitude are required to calculate Great Circle routes form the field site to the overwintering sites, and are also usually required when look up magnetic declination and magnetic inclination These data can be obtained in variety of ways.

  • VISIT THE LIBRARY. Topographic Maps that show latitude, longitude, and an average value for magnetic declination (variation) are available in map section of most libraries.

  • GO SHOPPING. Topographic maps for your area will usually be available at stores specializing in equipping hikers, backpackers, birders, hunters, and other outdoors types.

  • GO TO THE AIRPORT. Pilot and aviation supply stores are found at, or near airports and carry Aeronautical Charts. These charts are particularly useful because they plot latitude, longitude, altitude, and lines of magnetic declination (variation).

  • MEASURE IT YOURSELF. Handheld GPS receivers can quickly provide you with the altitude, latitude, and longitude of a site. I expect GPS receivers to become increasingly common in the field as they continue to drop in price.