[OSGeo-Brasil] Sistemas de referências incorretos no Proj, GDAL/OGR e PostGIS

Daniel Araujo Miranda miranda.dam em dpf.gov.br
Quinta Abril 26 11:24:34 EDT 2012


Realmente, achei o menu que você mencionou:

 > O EPSG tem entradas de tipo "Coordinate Transformation", voce pode ver
 > no site http://www.epsg-registry.org/ e colocar "Coordinate
 > Transformation"  no campo "Type:" e "sad69" no campo "Name"

Consegui o arquivo SAD96_003.gsb no IBGE (vem junto com o progrid), não 
achei esse arquivo em nenhum outro lugar (inclusive no epsg-registry).

Aparentemente a informação lá está certa, mas o site não fornece os 
parâmetros towgs84 (ou grids).




On 04/26/2012 09:55 AM, Etienne Tourigny wrote:
> On Wed, Apr 25, 2012 at 6:47 PM, Daniel Araujo Miranda
> <miranda.dam em dpf.gov.br>  wrote:
>> Etienne,
>>   Salvo engano, o spatiareference.org e o epsg.org não têm os parâmetros de
>> transformação (dX, dY, dZ, etc.). Você pode confirmar isso? Até baixei a
>> base de dados em postgresql mas não consegui achar essa informação.
>>   Se for isso mesmo, não tem como mandar as correções para eles, pois o
>> problema não é nos elipsóides, é principalmente nos parâmetros de
>> transformação, e isso eles não têm.
>>
>
> O EPSG tem entradas de tipo "Coordinate Transformation", voce pode ver
> no site http://www.epsg-registry.org/ e colocar "Coordinate
> Transformation"  no campo "Type:" e "sad69" no campo "Name"
>
> Os dados brutos do EPSG (epsg.org) são a principal fonte de dados para
> o GDAL/OGR e GeoTIFF.
>
>
> Não se porque spatialreference.org não tem os parametros TOWGS84  ...
>
> Na pagina http://spatialreference.org/about/ esta escrito "GDAL and
> Proj.4 are the backbone of this website", porém o GDAL tem os
> parametros TOWGS84.
>
> O GDAL/OGR tem varios parametros TOWGS84 (no arquivo datum_shift.csv)
> para cada DATUM, mas usa o "preferred datum" nas consultas:
>
> $ gdalsrsinfo EPSG:4618
>
> PROJ.4 : '+proj=longlat +ellps=aust_SA +towgs84=-57,1,-41,0,0,0,0 +no_defs '
>
> E no arquivo datum_shift.csv:
>
> $ grep 4618 /home/soft/share/gdal/datum_shift.csv
> 13,1864,4618,4326,Derived at 84 stations.,"For military purposes only.
> Accuracy 15m, 6m and 9m in X, Y and Z
> axes.",1358,-45,12.51,-81.4,-29.03,1,0,9603,-57,1,-41,,,,,1
> 14,1865,4618,4326,"Derived at 10 stations. Note: SAD69 not adopted in
> Argentina: see Campo Inchauspe (CRS code 4221).",For military purposes
> only. Accuracy 5m in each
> axis.,3215,-52.43,-21.78,-73.58,-53.65,1,0,9603,-62,-1,-37,,,,,0
> 15,1866,4618,4326,"Derived at 4 stations. Note: SAD69 not adopted in
> Bolivia: see PSAD56 (CRS code 4248).",For military purposes. Accuracy
> 15m in each axis.,1049,-22.9,-9.68,-69.66,-57.52,1,0,9603,-61,2,-48,,,,,0
> 16,1867,4618,4326,Derived at 22 stations.,"For military purposes only.
> Accuracy 3m, 5m and 5m in X, Y and Z
> axes.",3845,-35.71,7.04,-60.57,-29.03,1,0,9603,-60,-2,-41,,,,,0
> 17,1868,4618,4326,"Derived at 9 stations. Note: SAD69 not adopted in
> Chile.","For military purposes only. Accuracy 15m, 8m and 11m in X, Y
> and Z axes.",3227,-45,-17.51,-75.22,-67,1,0,9603,-75,-1,-44,,,,,0
> 18,1869,4618,4326,"Derived at 7 stations. Note: SAD69 not adopted in
> Colombia: see Bogota 1975 (CRS code 4218).","For military purposes
> only. Accuracy 6m, 6m and 5m in X, Y and Z
> axes.",3229,-4.24,12.51,-79.1,-66.87,1,0,9603,-44,6,-36,,,,,0
> 19,1870,4618,4326,"Derived at 11 stations. Note: SAD69 not adopted in
> Ecuador: see PSAD56 (CRS code 4248).",For military purposes. Accuracy
> 3m in each axis.,3241,-5,1.45,-81.03,-75.22,1,0,9603,-48,3,-44,,,,,0
> 20,1871,4618,4326,"Derived at 1 station. Note: SAD69 not adopted in
> Ecuador.",For military purposes. Accuracy 25m in each
> axis.,2356,-1.41,0.17,-91.71,-89.2,1,0,9603,-47,26,-42,,,,,0
> 21,1872,4618,4326,"Derived at 5 stations. Note: SAD69 not adopted in
> Guyana.","For military purposes only. Accuracy 9m, 5m and 5m in X, Y
> and Z axes.",3259,1.19,8.57,-61.39,-56.47,1,0,9603,-53,3,-47,,,,,0
> 22,1873,4618,4326,"Derived at 4 stations. Note: SAD69 not adopted in
> Paraguay.",For military purposes. Accuracy 15m in each
> axis.,1188,-27.58,-19.3,-62.64,-54.24,1,0,9603,-61,2,-33,,,,,0
> 23,1874,4618,4326,"Derived at 6 stations. Note: SAD69 not adopted in
> Peru: see PSAD56 (CRS code 4248).",For military purposes. Accuracy 5m
> in each axis.,3292,-18.35,-0.04,-81.4,-68.67,1,0,9603,-58,0,-44,,,,,0
> 24,1875,4618,4326,"Derived at 1 station. Note: SAD69 not adopted in
> Trinidad and Tobago.",For military purposes only. Accuracy 25m in each
> axis.,3143,9.99,10.89,-61.97,-60.86,1,0,9603,-45,12,-33,,,,,0
> 25,1876,4618,4326,"Derived at 5 stations. Note: SAD69 not adopted in
> Venezuela: see PSAD56 (CRS code 4248).","For military purposes only.
> Accuracy 3m, 6m and 3m in X, Y and Z
> axes.",3327,0.65,12.25,-73.38,-59.8,1,0,9603,-45,8,-33,,,,,0
> 26,1877,4618,4326,"Derived by Brazilian Institute of Geography and
> Statistics (IBGE) in 1989. Used by ANP. (Note: for historic reasons
> associated with one-time web url, tfm version uses initials IGBE, not
> IBGE). Replaced by SAD69 to WGS 84 (15) (tfm code 5528).",Medium and
> small scale mapping.,3845,-35.71,7.04,-60.57,-29.03,1,0,9603,-66.87,4.37,-38.52,,,,,0
> 543,1271,4293,4326,"Beware!  Schwarzeck CRS uses German legal metres.
> Example: Schwarzeck Lat 19d 35m 46.952s S Long 20d 41m 50.649s E;
> X=5623409.40 Y=2124618.00 Z=-2125847.62 GLM; X=5623485.86 Y=2124646.89
> Z=-2125876.53 m; WGS84 X=5624101.50 Y=2124748.97 Z=2126132.34
> m.","?",1169,-31.2,-16.99,8.32,25.28,1,0,9603,615.64,102.08,-255.81,,,,,0
>
> abs
> Etienne
>
>> O spatialreference.org tem os parâmetros de alguns. Por exemplo:
>>   http://spatialreference.org/ref/epsg/4224/
>> Os parâmetros citados são:
>>   +proj=longlat +ellps=intl +towgs84=-134,229,-29,0,0,0,0 +no_defs
>> Se isso for o Astro Chuá mesmo, os parâmetros estão errados.
>>
>> No proj4.7 (pacote proj-data):
>> /usr/share/proj/esri:
>>   <4224>  +proj=longlat +ellps=intl +towgs84=-134,229,-29,0,0,0,0 +no_defs
>>   no_defs<>
>> /usr/share/proj/epsg:
>>   <4224>  +proj=longlat +ellps=intl +no_defs<>
>>
>> Quanto às fontes do proj e postgis: O postgis não especifica (seção 4.3.1 do
>> manual), e o proj usa diversas fontes. A lista de arquivos do proj dá uma
>> dica:
>>
>> linhas arquivo
>> 7631   /usr/share/proj/epsg
>> 5937   /usr/share/proj/esri
>> 5189   /usr/share/proj/ntv1_can.dat
>> 2985   /usr/share/proj/alaska
>>
>> Por enquanto, estou expondo os parâmetros para o pessoal poder criticar.
>> Quando tivermos confiança nessas transformações, podemos procurar as fontes
>> desse dado para atualizá-lo.
>>
>>
>>
>> **********************
>> Aproveito para enviar a primeira errata:
>> Astro Chuá
>>        longlat
>>        4224
>>        +proj=longlat +a=6378388.0 +rf=297.00 +towgs84=-143.87,+243.37,-33.52
>>
>>        http://www.topografia.ufsc.br/Geodesia.pdf (referência não oficial)
>>
>> (o sinal do deltaZ estava trocado)
>> **********************
>>
>>
>>
>> --Miranda
>>
>>
>>
>> On 04/25/2012 04:45 PM, Etienne Tourigny wrote:
>>>
>>> Prezados,
>>>
>>> os dados de http://spatialreference.org usam o GDAL/OGR para obter os
>>> parametros. Eo não tenho certeza sobre a fonte que usam proj.4 e
>>> postgis.
>>>
>>> A fonte de GDAL/OGR é a base EPSG (epgs.org / epsg-registry.org).
>>> Qualquer erro tem ser ser encaminhado ao EPSG, e esse serà propagado
>>> ao softwares citados.
>>>
>>> Etienne
>>>
>>> On Wed, Apr 25, 2012 at 4:24 PM, Luiz Motta<motta.luiz em gmail.com>    wrote:
>>>>
>>>> Daniel,
>>>>
>>>> Vou ver com o Thiago (Terra Legal - MDA/INCRA) como ele está trabalhando
>>>> com
>>>> as projeções com Postgis e GDAL/OGR.
>>>>
>>>> Os FOSS4G trabalha seguindo a definição da proj4
>>>> (http://spatialreference.org).
>>>>
>>>> Abs
>>>> Luiz
>>>>
>>>> Em 25 de abril de 2012 16:02, Daniel Araujo
>>>> Miranda<miranda.dam em dpf.gov.br>
>>>> escreveu:
>>>>
>>>>> Caros, fiz uma pesquisa recente e descobri que os parâmetros de
>>>>> conversão
>>>>> para diversos sistemas de coordenadas (SRS, CRS) brasileiros estão
>>>>> incorretos nos seguintes aplicativos:
>>>>>
>>>>> Proj4
>>>>> GDAL/OGR
>>>>> PostGIS
>>>>> e talvez outros.
>>>>>
>>>>> Eles estão com as mesmas informações que o site
>>>>> http://spatialreference.org/ (vide a opção proj4 para revelar os
>>>>> parâmetros
>>>>> de transformação)
>>>>>
>>>>> Levantei os seguintes parâmetros que acredito estarem corretos. Estou
>>>>> divulgando esses dados aqui para vocês utilizarem se tiverem interesse e
>>>>> para criticarem se houver algo errado (Motta, me ajudaria muito se pelo
>>>>> menos você desse uma olhada!).
>>>>>
>>>>> --Miranda
>>>>>
>>>>>
>>>>> organização:
>>>>> Datum
>>>>>         Projeção
>>>>>         EPSG
>>>>>         String PROJ
>>>>>         Referência
>>>>>
>>>>>
>>>>>
>>>>> sad69 apos 94
>>>>>         longlat
>>>>>         4618
>>>>>         +proj=longlat +a=6378160.0 +rf=298.25
>>>>> +towgs84=-67.35,+3.88,-38.22
>>>>>         RPR 01/2005 de 25/02/2005 - IBGE
>>>>>
>>>>> (ftp://geoftp.ibge.gov.br/documentos/geodesia/projeto_mudanca_referencial_geodesico/legislacao/rpr_01_25fev2005.pdf)
>>>>>
>>>>> sad69 antes de 94
>>>>>         longlat
>>>>>         4291
>>>>>         +proj=longlat +a=6378160.0 +rf=298.25
>>>>> +towgs84=-66.87,+4.37,-38.52
>>>>>         Resolução da Presidência do IBGE n° 23, de 21/02/89 (R.PR 23/89)
>>>>> (ftp://geoftp.ibge.gov.br/documentos/geodesia/pdf/rpr_2389.pdf)
>>>>>
>>>>> sicad
>>>>>         longlat
>>>>>
>>>>>         +proj=longlat +a=6378388.0 +rf=297.00
>>>>> +towgs84=-144.35,+242.88,-33.22
>>>>>         GDF DECRETO 32.575-2010_SICAD-SIRGAS,
>>>>> www.terracap.df.gov.br/internet/arquivos/0073607515.doc
>>>>>
>>>>> sicad
>>>>>         utm 23s
>>>>>
>>>>>         +proj=utm +zone=23 +south +units=m +a=6378388.0 +rf=297.00
>>>>> +towgs84=-144.35,+242.88,-33.22
>>>>>         GDF DECRETO 32.575-2010_SICAD-SIRGAS,
>>>>> www.terracap.df.gov.br/internet/arquivos/0073607515.doc
>>>>>
>>>>> Córrego Alegre
>>>>>         longlat
>>>>>         4225
>>>>>         +proj=longlat +a=6378388.0 +rf=297.00
>>>>> +towgs84=-205.57,+168.77,-4.12
>>>>>         https://www.mar.mil.br/dhn/chm/download/ita06.pdf, composição de
>>>>> ftp://geoftp.ibge.gov.br/documentos/geodesia/pdf/bservico1602.pdf com
>>>>> ftp://geoftp.ibge.gov.br/documentos/geodesia/pdf/rpr_2389.pdf
>>>>>
>>>>> Astro Chuá
>>>>>         longlat
>>>>>         4224
>>>>>         +proj=longlat +a=6378388.0 +rf=297.00
>>>>> +towgs84=-143.87,+243.37,+33.52
>>>>>         http://www.topografia.ufsc.br/Geodesia.pdf (referência não
>>>>> oficial)


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