[Talk-br] Proposal of import: Brazilian Geodetic Network (man_made=survey_points)

Sérgio V. svolk2 em hotmail.com
Terça Março 14 16:22:41 UTC 2017

Bom dia pessoal, estou preparando a proposta abaixo para o https://lists.openstreetmap.org/pipermail/imports/.

Por favor sintam-se livres para examinar.

Antecipadamente obrigado.

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I'm member of brazilian OSM users community.
I present here for discussion, and asking approval for, the proposal for the import of brazilian geodetic network of survey points (SGB - Sistema Geodésico Brasileiro).
Firstly, sorry if not good english. Also sorry for the technical problems that arose due to the size of elements in previously ill imported relation.

This proposal was previously formally informed in brazilian talk list in https://lists.openstreetmap.org/pipermail/talk-br/2017-March/012063.html .
(Also this post here will be copied to brazilian talk list.)

The discussions in Brazilian community: actually started in 6th march in Telegram channel of the brazilian community, where it has been carried on, and where we generally use to talk most (159 members, around some 80 users connecting daily and some 20 activelly communicating). Many members made remarks and suggestions about it and, after all arrangements, general aprovals for procedures and utility purpose.

The purpose of this proposal: is to import the survey points published by the brazilian government agency for geographical data (called IBGE - (http://www.ibge.gov.br/home/geociencias/geodesia/default_sgb_int.shtm).

The source data: is all produced and published by IBGE.
The government also publishes these data through the more general portal for brazilian spatial data (INDE: http://www.visualizador.inde.gov.br<http://www.visualizador.inde.gov.br/> - Menu: Redes Geodesicas), from where it was dowloaded.

About the licenses for the data: as said in previous exchange of messages of other brazilian OSM member with IBGE officials [1], and as stated by the brazilian national law for access to information (known as "LAI"), all the government data, including IBGE, is free for access, not even requiring to say what for it is intended [2] (the exceptions quoted in the law must not even be published by the government). IBGE officials explicitly stated, as in previous quoted messages, it's free for OSM purposes, for copy, sharing and changes, since quoting the source, and not requiring further back communication.

The aim of the import: is to have all these points with their precise coordinates provided by the government, placed in OSM brazilian map to help on aligning imagery, fixing borders, found places in remote regions, etc.

It can be objected: found no survey point in imagery on the ground.
That's true. Many things pedestrians have mapped can't be seen on sattelite imagery now, like door numbers, shop names, highway signals, and many other small things, perhaps also fire_hidrants, etc. It usually resides all on local mapper's word.
Also imagery resolution is improving constantly, so perhaps not too later we all can see many more things on sattelite imagery.
Anyway, the government, through its data itself and its official reports of survey points, states they are there on the ground.

As a single example: there's a survey point (a small plate) over a boundary_stone in the Brazil-Venezuela-Guyana triple border, reported in [3]. It seems not visible in imagery, nor the boundary_stone. At least I still haven't found it (but I'm looking for). But just seeing this officialy reported point in JOSM (5.2018977222<tel:(201)%20897-7222>, -60.7375541111)[4] indicates this triple border in OSM is currently more than 1km far from that official measurement, thus deserving some revision.

Other general informations:
-All the objects proposed to import came previously converted by IBGE in WGS84 format in the original downloaded shape file.
-There will be no relation (in OSM peculiar concept for relation) to be stablished between these individual points.
-Only are meant to be imported the portion of the stations classified as in good conditions, leaving aside the ones destructed or not found as quoted in the official reports. So the final total number of points to be imported is smaller than in the original shp.

The proposed tags are these (english translation or meaning below in parenthesis):

description=Rede Geodésica do IBGE - Estação SAT DOPPLER
    (=IBGE Geodetic Network - <6 types of station, for: SAT DOPPLER; SAT GPS; Polygonal; Triangulation; Elevation Reference; Permanent GNSS>); by these 6 types of description= station...*... the data is aimed to be also accessible for recalling and maintence.
ele=* (when geometric height available)
note:en=Please: do not displace the point (official coordinates)
note=Não deslocar o ponto (coordenadas originais do IBGE)
    (almost the same as note:en, with local exortation tone)
ref:loc=São Félix do Xingu
    (the locality where the point is, perhaps even not mapped itself)
    (the particular and unique name or number of the station)
    (the original shape file)
sourceːele = IBGE/MAPGEO2015
    (for Elevation Reference: MAPGEO2015 is the geoid model in Brazil)
    (to access the complete official report, sometimes it has photos and other info that help a bit more to identify)

The proposal is documented at:

Thank you in advance for your evaluation.
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[1] https://lists.openstreetmap.org/pipermail/imports/2013-July/001981.html
[2] http://www.acessoainformacao.gov.br/assuntos/conheca-seu-direito
[3] "Localização: Na parte mais alta do Monte Roraima, em território brasileiro...", says, "Location: In the upper part of Mount Roraima, in brazilian territory..." (http://www.bdg.ibge.gov.br/bdg/pdf/relatorio.asp?L1=90128)
[4] 05 ° 12 ' 06,8318 " N 60 ° 44 ' 15,1948 "W
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Sérgio - http://www.openstreetmap.org/user/smaprs
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