Lat/Long Display tab

Note: Although the screenshots used in this section are for the Sites module, the same geo-referencing tabs are implemented in the Collection Events module, and the description applies equally to Sites and Collection Events.

Geo-referencing information is stored on the Lat/Long tab, which has been designed to contain all locality co-ordinate information and associated error values:

Lat/Long

The Lat/Long tab is divided into two linked areas:

  • The Latitude/Longitude Details group of fields at the top of the tab.
  • The Latitude/Longitude List grid at the bottom of the tab.

As with other linked grids in EMu, data displaying in the Latitude/Longitude Details group of fields at the top of the tab depends on the row selected in the Latitude/Longitude List grid at the bottom of the tab: selecting a different row in the Latitude/Longitude List grid, displays a different set of values (opinion) in the Latitude Longitude Details group of fields.

Each row in the Latitude/Longitude List grid represents an opinion on the locality. For each opinion a set of latitude and longitude values can be defined. The Latitude/Longitude table located at the very top of the tab allows multiple points to be entered, with each point added as a row in the table. A single point specifies an exact location, while two points (generally) represent a line, three points represent a triangle and four a quadrilateral, etc.

First, a definition of the labels used to describe each field:

Label

Definition

Column

The name of the column in EMu's Sites and Collection Events modules.

Darwin Core Term

The name of the Darwin Core term for the column.

ABCD Identifier

The xpath for the Access to Biological Collection Data identifier for the column.

Description

A brief description of the content of the column.

Example Values

Samples values for the column.

Label

Definition

Column:

LatLatitude_nesttab

Darwin Core Term:

verbatimCoordinates
verbatimCoordinateSystem

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / CoordinatesText
DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesGrid / GridCellSystem

Description:

The latitude value for a given point specified in Degrees / Minutes / Seconds (DMS) format. The direction (either N or S) must be specified. The value must be between zero and 90 degrees. The value may be entered in either DMS or decimal format (decimal values are converted to DMS).

Example Values:

12 34 15 N
23 15 S
27 32 18.45 S

Label

Definition

Column:

LatLatitudeDecimal_nesttab

Darwin Core Term:

decimalLatitude

ABCD Identifier:

DataSets / DataSet / Units/Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / LatitudeDecimal

Description:

The latitude value for a given point specified as a decimal number. The direction is not shown, as a negative value implies south and a positive value implies north.

Example Values:

12.34267
-27.9453765

Label

Definition

Column:

LatLatitudeVerbatim_nesttab

Darwin Core Term:

verbatimLatitude

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / VerbatimLatitude

Description:

The latitude text as it appears originally. In many instances the value was recorded by hand on a label or in a journal. The latitude value as it appears on the label or in the journal is entered into this field.

Example Values:

North 12 34
27° 15' 18" South

Label

Definition

Column:

LatLongitude_nesttab

Darwin Core Term:

verbatimCoordinates and verbatimCoordinateSystem

ABCD Identifier:

DataSets / DataSet / Units/Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / CoordinatesText and DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesGrid / GridCellSystem

Description:

The longitude value for a given point specified in Degrees / Minutes / Seconds (DMS) format. The direction (either E or W) must be specified. The value must be between zero and 180 degrees. The value may be entered in either DMS or decimal format (decimal values are converted to DMS).

Example Values:

140 12 15 E
62 15 W
62 30 24.45 W

Label

Definition

Column:

LatLongitudeDecimal_nesttab

Darwin Core Term:

decimalLongitude

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / LongitudeDecimal

Description:

The longitude value for a given point specified as a decimal number. The direction is not shown, as a negative value implies west and a positive value implies east.

Example Values:

140.9236
-60.327656

Label

Definition

Column:

LatLongitudeVerbatim_nesttab

Darwin Core Term:

verbatimLongitude

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / VerbatimLongitude

Description:

The longitude text as it appears originally. In many instances the value was recorded by hand on a label or in a journal. The longitude value as it appears on the label or in the journal is entered into this field.

Example Values:

East 140 12
62° 30' 24" West

Label

Definition

Column:

LatModifier_nesttab

Darwin Core Term:

N/A

ABCD Identifier:

N/A

Description:

A modifier that applies to both the latitude and longitude values. The modifier generally provides feedback about the accuracy of the values.

Example Values:

Approximate
?

Label

Definition

Column:

LatComment_nesttab

Darwin Core Term:

georeferenceRemarks

ABCD Identifier:

DataSets / DataSet / Units / Unit/Gathering / SiteCoordinateSets / SiteCoordinates / GeoreferenceRemarks

Description:

General comments that apply to a particular latitude and longitude pair. If a comment applies to the overall opinion, the Notes field should be used.

Example Values:

Last digit of latitude value difficult to read. Could be 8 or 9.
Verbatim values were smudged and difficult to read.

Label

Definition

Column:

LatDetSource_tab

Darwin Core Term:

georeferenceSources

ABCD Identifier:

DataSets / DataSet / Units / Unit/Gathering / SiteCoordinateSets / SiteCoordinates / GeoreferenceSources

Description:

The source of the latitude/longitude pairs. It may be the gazetteer and version used, the map details, the name of the institution that provided the co-ordinates or the model of the GSP unit used.

Example Values:

Alexandria Digital Library Gazetteer, Version 1.2
AMG553874

Label

Definition

Column:

LatLatLongDetermination_tab

Darwin Core Term:

georeferenceProtocol

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinateMethod

Description:

The method used to calculate the latitude/longitude pairs. Each method used should be viewed as a separate set of readings resulting in one opinion per method used per person making the determination.

Example Values:

GPS
On-line Gazetteer
Map

Label

Definition

Column:

LatDeterminedByRef_tab

Darwin Core Term:

georeferencedBy

ABCD Identifier:

N/A

Description:

A link to the Parties record of the person who calculated the latitude/longitude values used.

Example Values:

Wilson, Garry (ANM)
National Museum

Label

Definition

Column:

LatDetDate_tab

Darwin Core Term:

N/A

ABCD Identifier:

N/A

Description:

The date the latitude/longitude values were calculated.

Example Values:

12 September 2009
02 / 04 / 2008

Label

Definition

Column:

LatRadiusVerbatim_tab

Darwin Core Term:

coordinatePrecision

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / AccuracyStatement

Description:

The error distance as recorded originally. When latitude/longitude values are calculated the value derived is not exact. There is an error component whose size depends on the method used to derive the values. The radius is the distance from the specified point in which the actual location should appear.

Example Values:

12 miles
2000 metres

Label

Definition

Column:

LatRadiusProbability_tab

Darwin Core Term:

pointRadiusSpatialFit

ABCD Identifier:

DataSets / DataSet / Units / Unit/Gathering / SiteCoordinateSets / SiteCoordinates / PointRadiusSpatialFit

Description:

The numeric probability (between 1 and 100) that a given location falls within the error distance specified. A value of 100 represents complete certainty.

Example Values:

90
100

Label

Definition

Column:

LatRadiusNumeric_tab

Darwin Core Term:

coordinateUncertaintyInMeters

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / CoordinateErrorDistanceInMeters

Description:

The numeric representation of Radius (Verbatim). The error distance is entered in metres typically, however the Units field allows other units to be specified.

Example Values:

2000
12.5

Label

Definition

Column:

LatRadiusUnit_tab

Darwin Core Term:

coordinateUncertaintyInMeters

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / CoordinateErrorDistanceInMeters

Description:

The unit type to apply to the Radius (Numeric) value.

Example Values:

metres
feet

Label

Definition

Column:

LatGeometry_tab

Darwin Core Term:

footprintWKT

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / FootprintWKT

Description:

The overall shape represented by the latitude/longitude values. For a single set of values a point is defined, however for two sets of points a line may be defined or the points may be corners of a bounding box or even just two disparate locations.

Example Values:

point
triangle
line

Label

Definition

Column:

LatDatum_tab

Darwin Core Term:

geodeticDatum and verbatimSRS

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / SpatialDatum

Description:

A datum is a set of reference points on the earth's surface from which measurements are made. For geodesy it is the points used to determine latitude and longitude values. Maps and GPS devices use a reference datum to determine co-ordinates.

Example Values:

WGS84
NAD83
AGM66

Label

Definition

Column:

LatPreferred_tab

Darwin Core Term:

N/A

ABCD Identifier:

N/A

Description:

Where multiple locality opinions are given (that is, more than one entry in the Latitude/Longitude List grid) a Yes value is enabled for the Preferred opinion. The Preferred entry is used in Summary Data and preferred centroid calculations.

Example Values:

Yes
No

Label

Definition

Column:

LatDeriveCentroid_tab

Darwin Core Term:

N/A

ABCD Identifier:

N/A

Description:

Whether EMu should calculate the centroid value (System) or whether the value is entered by the user (User). The centroid is the weighted middle point of all the latitude/longitude pairs entered for the current opinion.

Example Values:

System
User

Label

Definition

Column:

LatCentroidLatitude0

Darwin Core Term:

verbatimCoordinates and verbatimCoordinateSystem

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / CoordinatesText and DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesGrid / GridCellSystem

Description:

The latitude value representing the weighted middle point of all the latitude/longitude pairs provided for the current opinion. In most cases this value is calculated automatically. The value is shown in DMS format.

Example Values:

12 34 15 N
23 15 S
27 32 18.45 S

Label

Definition

Column:

LatCentroidLatitudeDec_tab

Darwin Core Term:

decimalLatitude

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / LatitudeDecimal

Description:

The centroid latitude value in decimal format.

Example Values:

12.34267
-27.9453765

Label

Definition

Column:

LatCentroidLongitude0

Darwin Core Term:

verbatimCoordinates and verbatimCoordinateSystem

ABCD Identifier:

DataSets / DataSet / Units / Unit/Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / CoordinatesText and DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesGrid / GridCellSystem

Description:

The longitude value representing the weighted middle point of all the latitude/longitude pairs provided for the current opinion. In most cases this value is calculated automatically. The value is shown in DMS format.

Example Values:

140 12 15 E
62 15 W
62 30 24.45 W

Label

Definition

Column:

LatCentroidLongitudeDec_tab

Darwin Core Term:

decimalLongitude

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / CoordinatesLatLong / VerbatimLongitude

Description:

The centroid longitude value in decimal format.

Example Values:

140.9236
-60.327656

Label

Definition

Column:

LatGeoreferencingNotes0

Darwin Core Term:

georeferenceRemarks

ABCD Identifier:

DataSets / DataSet / Units / Unit / Gathering / SiteCoordinateSets / SiteCoordinates / GeoreferenceRemarks

Description:

Any notes that apply to the overall set of latitude/longitude values or the error distance.

Example Values:

GPS required re-calibration so readings may not be as accurate as first thought.
Readings taken from version 1.2 of map. Version 1.3 may provide better values.

The Lat/Long tab allows multiple opinions to be recorded. One of these opinions is marked as Preferred by having the value Yes recorded in the Preferred combo box. Only one opinion may be marked as Preferred. Changing Preferred to Yes for a given opinion forces all other opinions to be set to No.

In many cases the Preferred opinion is sufficient when producing reports or displaying data on the Internet. To provide easy access to the Preferred opinion, EMu copies most of the geo-referencing data for the Preferred opinion into a separate set of columns. These columns can be used for reporting, displaying on the Internet and even searching. The table below lists the names of the Preferred opinion columns:

Name

Column

Copied from

Preferred Latitude (DMS)

LatPreferredLatitude0

LatLatitude_nesttab

Preferred Latitude (Dec)

LatPreferredLatitudeDec

LatLatitude_nesttab

Preferred Longitude (DMS)

LatPreferredLongitude0

LatLongitude_nesttab

Preferred Longitude (Dec)

LatPreferredLongitudeDec

LatLongitudeDecimal_nesttab

Preferred Centroid Latitude (DMS)

LatPreferredCentroidLatitude

LatCentroidLatitude0

Preferred Centroid Latitude (Dec)

LatPreferredCentroidLatDec

LatCentroidLatitudeDec_tab

Preferred Centroid Longitude (DMS)

LatPreferredCentroidLongitude

LatCentroidLongitude0

Preferred Centroid Longitude (Dec)

LatPreferredCentroidLongDec

LatCentroidLongitudeDec_tab

Preferred Determination Method

LatPreferredDetermination

LatLatLongDetermination_tab

Preferred Determined By Ref

LatPreferredDeterminedByRef

LatDeterminedByRef_tab

Preferred Determination Date

LatPreferredDetDate

LatDetDate_tab

Preferred Determination Source/Description

LatPreferredDetSource

LatDetSource_tab

Preferred Datum

LatPreferredDatum

LatDatum_tab

Preferred Radius Numeric

LatPreferredRadiusNumeric

LatRadiusNumeric_tab

Preferred Radius Unit

LatPreferredRadiusUnit

LatRadiusUnit_tab

Preferred Radius Verbatim

LatPreferredRadiusVerbatim

LatRadiusVerbatim_tab

Preferred Radius Probability

LatPreferredRadiusProbability

LatRadiusProbability_tab

Preferred Geometry

LatPreferredGeometry

LatGeometry_tab

Preferred Georeferencing Notes

LatPreferredGeoreferencingNotes

LatGeoreferencingNotes0

Note: When supplying data in Darwin Core or ABCD format, the Preferred values may provide sufficient information.

When data is entered into the Lat/Long tab a number of values are computed. In particular:

  • All latitude and longitude values entered in DMS format have the equivalent decimal value computed and displayed. The computed value is displayed in red.
  • All latitude and longitude values entered in decimal format have the equivalent DMS value computed and displayed. The computed value is displayed in red.
  • The first opinion entered has Preferred set to Yes automatically. Setting another opinion to Yes results in all other options having Preferred set to No.
  • For each opinion entered the centroid value is computed if the Derive Centroid value is set to System. The calculation uses the entered values, not the computed values, when determining the centroid.

The computed values are also calculated when records are inserted via the Import tool or any other insertion mechanism (e.g. web based insertions, texload bulk loads, etc.).

Note: In the Options box it is possible to set a colour for text displaying in a computed field.