<div>
<div class="content wysiwyg-content">
Hi,<br />
<br />
I am developing on a Pocket PC using a Teletype GPS adapter. After reading and parsing NMEA sentence data in order to obtain the Longitude, Latitude and Elliposidal Height, &nbsp;I want to convert these values into a northing and easting so I can display the point on a Ordnance Survey National Grid map.<br />
<br />
If I am correct I can use a helmert transformation to convert from WGS84 to OSGB36, before projecting the resulting values to obtain the Northing and Easting. Is this a reasonable way to convert the coordinates?<br />
<br />
Apparently this will only offer limited accuracy of up to 5m. On the <a href="http://www.gps.gov.uk/" rel="ugc">http://www.gps.gov.uk/</a>&nbsp;website the OSTN97 &amp;&nbsp;OSTN02 transformations are mentioned giving far greater accuracy. Does anyone know if it is possible to use these transformations, and where the required information can be found? <br />
<br />
Many thanks for your time,<br />
<br />
AT.
</div>
</div>


Hi,

I am developing on a Pocket PC using a Teletype GPS adapter. After reading and parsing NMEA sentence data in order to obtain the Longitude, Latitude and Elliposidal Height,  I want to convert these values into a northing and easting so I can display the point on a Ordnance Survey National Grid map.

If I am correct I can use a helmert transformation to convert from WGS84 to OSGB36, before projecting the resulting values to obtain the Northing and Easting. Is this a reasonable way to convert the coordinates?

Apparently this will only offer limited accuracy of up to 5m. On the http://www.gps.gov.uk/ website the OSTN97 & OSTN02 transformations are mentioned giving far greater accuracy. Does anyone know if it is possible to use these transformations, and where the required information can be found? 

Many thanks for your time,

AT.

Converting GPS Longitude/Latitude to OS National Grid Easting/Northing

The Global Positioning System (GPS) is a space-based global navigation satellite system (GNSS) that provides reliable location and time information in all weather and at all times and anywhere on or near the Earth when and where there is an unobstructed line of sight to four or more GPS satellites. A geographic information system (GIS) or geospatial information system is any system that captures, stores, analyzes, manages, and presents data that are linked to location(s). In the simplest terms, GIS is the merging of cartography, statistical analysis, and database technology.