Re: Geolocations

Dale DePriest wrote:


Paul Blair wrote:

Dale DePriest wrote:



Kerry Raymond wrote:

I think there are a couple of points here.

Firstly, the desire is to have latitude/longitude in addition to the normal place information. Nobody is wanting to take away the ability to have a town name or a street address. However, place names change. Therefore, it is useful to augment place name information with a set of numeric coordinates that will identify a spot long after the place name has changed.

As for how precise the coordinates are, that depends on how digits you use and how precise you can get with the technology you are using (e.g. a map or GPS). While GPS officially has an accuracy of about 10 metres, in practice most of the time the accuracy is 1-3 metres, which is quite adequate to identify the location of a house, but not a grave.

I've certainly spent a lot of time scouring old maps and driving/walking about an area in the hope of finding some location connected with family history. When I find something, I know routinely try to mark its location with GPS. The next step (from my point of view) is finding a good solution to publishing this information so others can benefit. Clearly locations specific to my own family history (e.g. a house) can be put recorded in my Family Tree Maker database and exported to GED (to exchange with other family members), but for locations of interest to a wider community, e.g. an abandoned cemetery, a street with a changed name, we don't really have a registry on the WWW for publishing that information.

Kerry




I agree with you accuracy information. My only problem is a place entry in my database is used for lots of people and lots of events. If I can only make an entry for one place I either have to have a huge number of places or I have to compromise my location data. That is why I want lat/lon tied to events and not places.

Dale


You're probably correct, but hardly feasible. We just don't have that sort of info, for the most part. For example, my mum was born in Milligan Street, Perth. Not a long street, but today most of it is a carpark. If I put a point in the middle of the road halfway along its length, that's all I can do. That ties it to the event and the place, but is not perfect. However, I'm satisfied with the result. And when Milligan St vanishes under a block of units, as it surely will, the spot is sufficiently identified.

Paul

I don't understand the comment hardly feasible. Certainly it is not feasible to record lat/lon values for every event in the database but that does not mean you should not for those you can. Nor does it mean there is no value in doing so. That is why I want a program that will keep track of lat/lon per event although per place could also be added for backup. The only problem is, so far, all I have found will only do it for places. An earlier legacy did it for events but then they abandoned it. Once you start getting some decent lat/lon values then mapping the data starts becoming feasible.

Dale

Dale:

Sorry, I may have misread what you say. But my point is that locations in this environment are all a compromise...I pick a point roughly in the middle of cemeteries, I spy via Google Earth for buildings, but 95% of the time I have to be "about" correct. And I can live with that...

Paul
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Relevant Pages

  • Re: Geolocations
    ... As for how precise the coordinates are, that depends on how digits you use and how precise you can get with the technology you are using (e.g. a map or GPS). ... I've certainly spent a lot of time scouring old maps and driving/walking about an area in the hope of finding some location connected with family history. ... My only problem is a place entry in my database is used for lots of people and lots of events. ... Certainly it is not feasible to record lat/lon values for every event in the database but that does not mean you should not for those you can. ...
    (soc.genealogy.computing)
  • Re: Dumbing Down GPS, Lat/Long Getting Lost
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  • Re: GPS units
    ... lat/lon a week after I mark the spot? ... Every GPS unit I've owned (and I'm up to my fourth generation ... I'd also suggest using UTM rather than Lat/Long... ... as just recording a lat/long directly from the GPS ...
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  • Re: A Radius Search?
    ... for your purposes it's unlikely you need a very accurate great circle calculation. ... You may be able to obtain a computer-readable database for the zip code information from the United States Post Office. ... You could subscribe to/license a map database that includes support for translating addresses to lat/lon, but assuming you know in advance the specific "available locations", you may find it more cost-effective to just make your own database with the lat/lon precalculated. ... I don't know the licensing terms, but it's possible you could use the Google Maps Javascript API to do the initial lat/lon calculations, to be stored in your database. ...
    (microsoft.public.dotnet.languages.csharp)
  • Re: Geolocations
    ... As for how precise the coordinates are, that depends on how digits you use and how precise you can get with the technology you are using (e.g. a map or GPS). ... I've certainly spent a lot of time scouring old maps and driving/walking about an area in the hope of finding some location connected with family history. ... Clearly locations specific to my own family history can be put recorded in my Family Tree Maker database and exported to GED, but for locations of interest to a wider community, e.g. an abandoned cemetery, a street with a changed name, we don't really have a registry on the WWW for publishing that information. ... If I can only make an entry for one place I either have to have a huge number of places or I have to compromise my location data. ...
    (soc.genealogy.computing)