EIVA GEOCALCdownload.eiva.dk/online-training/GeoCalc.pdf · 8 Position vs KP/DOL ..... 14 9 File...

08 Fall

EIVA GEOCALC

A GEODETIC TOOLBOX

Author: OKR

Last update: 15/11/2012

Version:3.9

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Contents 1 Introduction ..................................................................................................................... 3

2 Geodesy ........................................................................................................................... 4

2.1 Defining Geodesy ....................................................................................................... 5

2.2 Defining datum shift.................................................................................................... 6

3 Convert a point ................................................................................................................ 7

4 Shift a point ..................................................................................................................... 8

5 Convert a file ................................................................................................................. 10

6 Shift a file ....................................................................................................................... 12

7 Chen and Millero 1977 .................................................................................................. 14

8 Position vs KP/DOL ...................................................................................................... 14

9 File formats .................................................................................................................... 15

9.1 XY ............................................................................................................................. 16

9.2 Decimal degree ........................................................................................................ 16

9.3 Degree and minutes ................................................................................................. 16

9.4 Degree, minutes and seconds ................................................................................. 16

9.5 Radians .................................................................................................................... 17

10 XTF Converter ............................................................................................................ 17

11 About .......................................................................................................................... 17

GeoCalc.docx

Last update: 15/11/2012 of 18

1 Introduction

GeoCalc is a toolbox with utilities to convert between geographical and external

coordinates, to perform datum shifts etc.

The main window lists the actual setting (source geodesy, datum shift and destination

geodesy), includes buttons and menu entries to change geodesy and a buttons and menus

to perform various calculations.

The lower part of the window is a result list box with copy of all calculations. Pressing the

Clear button can empty the list. Is you don’t want the system to display file based calculation

just deselect the List ASCII file conversion tick box.

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2 Geodesy

The calculator is based on a rather advanced geodesy setting (as known in a.o. NaviEdit).

The operator must define a source geodesy (ellipsoid and projection), a set of datum shift

parameters (method and 7 parameters) and a destination geodesy (ellipsoid and projection)

as illustrated above.

The data conversion (singe point, ASCII file or XTF file) are all performed in the source

geodesy, as it’s simple a conversion between X/Y and Lat/Long.

The data shift routines (single point or ASCII file) operates between source and destination,

as it uses the defined datum shift parameters.

GeoCalc.docx


2.1 Defining Geodesy

Press the Change button and the above dialogue pops-up. The system uses a common

DLL with other EIVA products for this setting.

You may select between a series of available ellipsoids and projections. Depending on the

type, it’s possible to enter various parameters (e.g. UTM zone in the above sample).

When operating in the US; you may use a set of pre-defined zones via the Load US State

Plane:

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2.2 Defining datum shift

GeoCalc.docx


Press the Change button and the above dialogue pops-up. The system uses a common

DLL with other EIVA products for this setting.

You may select between a series of predefined shifts or use a user defined where you might

enter the 7 parameters.

You should only select the Normal method or the North sea method – the two

others aren’t supported in this utility module. Selecting them results in error

messages like:

GeoCalc supports more or less any combination of shifts between settings. A lot

of these make no sense at all. Some illegal combinations are caught by the

module and gives warnings like:

3 Convert a point

Press the convert point button or activate the menu Calculate, Convert point menu entry

and the following dialogue pops-up:

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You are now allowed to convert between X/Y and lat/long in your selected source geodesy

(see the top line). Entering the coordinates and pressing the left/right arrow buttons perform

the conversion.

The geographical coordinates may be entered/displayed in three formats:

DD.dddddd Decimal degree with as many digits as you want (Eg. 12.345678°)

DD MM SS.ssss Degree, minutes and seconds with as many digits as you want (Eg. 12°20’ 44.4408”)

DD MM.mmmmm Degree and minutes with as many digits as you want (Eg. 12°20.74068’)

The “sign” of the geographical coordinates are defined by E/W or N/S.

It’s possible to print (always on default printer) the result by pressing the printer icon. This is

based on a freeware printer utility, and the result is a simple bitmap:

This will only work if the screen colour resolution is either 32 but true colour or 256 colours.

The result of each conversion is finally displayed in the main window list box.

4 Shift a point

Press the shift point button or activate the menu Calculate, Shift point menu entry and the

following dialogue pops-up:

GeoCalc.docx


Here it’s possible to shift coordinates between source and destination geodesy. The upper

part of the window allows you to enter the coordinates as either X/Y or Lat/Long (DD.ddddd,

DD MM.mmmm or DD MM SS.ssssss). Having entered the values you may shift them by

pressing From <source> or From <destination> buttons. The result is now shown in the

middle part of the dialogue, as the left part gives result in source and right part in destination

geodesy.

The used 7 parameters are included in the lower part of the dialogue.

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The dialogue can be printed using the printer icon and the result are displayed in the main

window list box:

5 Convert a file

It’s possible to convert an entire ASCII file between X/Y and Lat/long.

1. Shall we display all results in the list box? If yes select the “List ASCII file conversion”

2. Shall we display the resulting file after conversion? If yes – select the “Display file after creation”.

3. Press Convert ASCII File or activate Calculate, Convert ASCII File in the menu

GeoCalc.docx


4. Select the file(s) you want to convert 5. For each file you must specify the format of the input file:

If the file is in Lat/Long, then you must specify how to interpret the fields. You may select between decimal degrees (DD.dddd, DD MM.mmmm or DD MM SS.ssss) or radians (RR.rrrr). For details on the formats please see later section.

6. Next you must specify the format of the output file:

a. In the left section you select how (multiple choice) to represent the position. b. In the right section you must specify how to represent lat/long c. Shall we include a header in the file (date, time and used geodesy)? d. Shall we include a copy of original data in the file?

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7. The system now creates a new file named as the original but with the extension “-Conv.txt”:

6 Shift a file

It’s possible to convert an entire ASCII file between X/Y and Lat/long.

1. Shall we display all results in the list box? If yes select the “List ASCII file conversion”

2. Shall we display the resulting file after conversion? If yes – select the “Display file after creation”.

3. Press Shift ASCII File or activate Calculate, Shift ASCII File in the menu 4. Select the file(s) you want to convert 5. For each file you must specify the format of the input file:

If the file is in Lat/Long, then you must specify how to interpret the fields. You may select between decimal degrees (DD.dddd, DD MM.mmmm or DD MM SS.ssss) or radians (RR.rrrr). For details on the formats please see later section.

GeoCalc.docx


6. Next you have to specify if the shift is forwards or backwards, i.e. from source or destination:

7. Next you must specify the format of the output file:

a. In the left section you select how (multiple choice) to represent the position. b. In the right section you must specify how to represent lat/long c. Shall we include a header in the file (date, time and used geodesy)? d. Shall we include a copy of original data in the file?

8. The system now creates a new file named as the original but with the extension –Shift.txt:

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7 Chen and Millero 1977

The Calculate, Chen and Millero menu allows you to perform calculations on CTD data:

If you enter pressure (in deci bar), temperature (degree Celsius) and salinity (PSU) and

press the Calculate SV button, then it calculates the sound velocity based on the official

UNESCO formula.

If you instead input pressure, temperature and sound velocity and press the Calculate Sal

button, then it makes an iterative calculation on the corresponding salinity. It’s done in a

cyclic process, where it searches for the salinity which gives the best fitting sound velocity.

8 Position vs KP/DOL

The program includes a calculator in the Calculation menu that allows you to convert data

between position (Easting, Northing) and runline data (KP and DOL)2

2 KP is kilometer Point and DOL is Distance Off Line

GeoCalc.docx


Before using it you must load a runline in the top line. Run line files supported is RLX and

RLE from the NaviPac format library.

You may now enter position or kp/dol values and convert but using the two first buttons.

The two last buttons allow you to do so for one or more ASCII files.

The files must be formatted very simple as it must have either easting, northing or kp, dol as

the first two items.

9 File formats

We have tried to make an intelligent reader for the ASCII files, so it will automatically search

for data in the input files.

This is performed after the following simple rules:

All lines starting with a ‘#’ are considered to be comments and will be ignored.

All non comment lines must include exactly one position

The selected position format can start at any number, as specified in the input dialogue – e.g. XY file will search for the no-skip + two numerical fields in a line

All non-numerical characters are ignored, eg. “ xyz 123.45 XXX 2345.68” results in the two numbers 123.45 and 2345.68.

The reader uses a few fixed separators: ‘,’ ‘:’ ‘;’ ‘|' After such a delimiter at will always read a number, i.e. “ xy:z 123.45 XXX 2345.68” will fail as it contains a ‘:’ in the middle of nowhere.

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9.1 XY

The file contains positions as easting and northing (or the opposite) with as many ciphers as

requested.

Sample:

519999.9973,5999999.9052, 54.146556, 9.306175

9.2 Decimal degree

The file contains positions as latitude and longitude (or the opposite) represented as

decimal degree with as many ciphers as requested.

Sample:

decimal degree 54.146556, 9.306175

Western and southern values must be defined with -

9.3 Degree and minutes

The file contains positions as latitude and longitude (or the opposite) represented as degree

and decimal minutes with as many ciphers as requested. The reader will search for 4

numbers in each line.

Sample:

dd mm_mmmmmmmmmmmm 054°08.793345' 009°18.370483'

Western and southern values must be defined with – in front of both degree and minutes.

9.4 Degree, minutes and seconds

The file contains positions as latitude and longitude (or the opposite) represented as

degree, minutes and decimal seconds with as many ciphers as requested. The reader will

search for 6 numbers in each line.

Sample:

Lat and long in dd mm dd 54°08'47.60072" 9°18'22.22899"

GeoCalc.docx


Western and southern values must be defined with – in front of degree, minutes and

seconds. Eg:

54° 8' 51.7705" -20° -41' -37.7968"

9.5 Radians

The file contains positions as latitude and longitude (or the opposite) represented as radians

with as many ciphers as requested. The reader will search for 2 numbers in each line.

Sample:

XXX___ZZZ 0.945036, 0.162423

10 XTF Converter

The module contains a special XTF converter module, which reads XTF files (Simrad

based) and converts positions in lat/long to X/Y coordinates using the source geodesy).

Activate Calculate, Convert XTF file and select the file you want to convert. A new files is

now created with the original name plus an extension “.XY.XTF”.

During the conversion some errors might occur:

The file has a flag (XTFFILEHEADER.NaviUnits) that must be 3 if positions are in lat/long.

The above example with 0 is a file already in X/Y co-ordinates.

The file header format (XTFFILEHEADER.FileFormat) should always be 123. If the above

happens, please check if the file is in XTF format.

11 About

The help, About menu results in the following dialogue:

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In case of problems, please note down version number and release data and inform EIVA

a/s ([email protected])

mailto:[email protected]

EIVA GEOCALCdownload.eiva.dk/online-training/GeoCalc.pdf · 8 Position vs KP/DOL ..... 14 9 File...

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