Thanks to all those who responded.
Check out replies C and I, which describe the process of geocoding by eye "aka
heads-up digitizing".
Speacial thanks to Peter who had a table with the local map reference and very
generously geocoded my table for me!!!
Original question:
>I have a map in a particular projection (AMG Zone 56 (AGD 84)).
>I have a table with 171 entries whose only spatial attribute is a local
>map reference (eg Map12, A7 or Map 9, M3).
>I have a hard copy map (local map reference) with each entry marked in its
>correct location.
>I need to geocode each entry.
>Given there is only 171 entries,
>I am prepared to do each one manually, by eye.
>This seems the fastest way.
>Not sure how to do this, any suggestions??
>OR, is there a better way?
Below is a summary of various methods
A. do it manually (by eye). you will have it completely done by the time you
have it set up for the computer to do it. you would then have the additional
time to manually check all the ones the computer could not find.
==================================================
B. Are the map panels arranged in such a way that you could make a grid and classify
the grid cells (polygons) with the map numbers easily? If so, you
could create that then geocode these (and future) records against that
table.
===================================================
C. It's relatively easy to add point objects to an existing MapInfo table by
"geocoding by eye" aka "head-up digitizing" . What works for me is:
1. make the target table mappable, that is "add the Obj column", and make
sure that it has the required Projection.
2. open a reference map of the area where the points are located
3. open your target table as a browser
4. tile the two windows (map and browser)
5. add the target table as the top map layer of the map and make it editable
6. select the Symbol tool from the Drawing toolbar
7. move the cursor over the "record selector" box at the left of the first
row in the browser window
(the cursor changes to an arrow) and click - the record is selected
8. move the cursor over the map (the cursor changes to a drawing tool) and
click at the location for the first row - the symbol is placed on the map
AND in the Obj column of the selected record
repeat steps 7 and 8 for each row in the table.
Hint: it makes thinks much less confusing if, when you add the target table
to the map, you turn on autolabels for that layer. Then, as soon as you add
a new point to the map, its label appears
=======================================================
D. i) Use a digitizer (easiest and most accurate)
or
ii) Construct a grid of polygons corresponding to the hardcopy map
reference, then geocode to these attributed polygons.
=======================================================
E. The only other option is to scan, then georeference the raster image behind
the layer you are working on. Then it just a matter of click on the dots on
the raster image.
That is hoping you have a scanner etc.
=======================================================
F. why not read the lat/long off of the map for each point. then make a table
with the lat/long info which mapinfo can then automatically create the
points for those lat/long values. Probably what you planned on doing
anyway...
=======================================================
G. That could work if you have good topo for the backdrop.
Alternatively, you have two options to increase your accuracy:
1. Get out your drafting scale and physically measure the distances. Enter
them into your table (in new X/Y columns) and Create Points.
2. Scan the paper map and register it in MapInfo, the just digitize over the
on-screen image.
You may have to do some Update columns and stuff to get your origianl table
to match the points you create.
=======================================================
H. You got to make your table editable in layer control, open your table browser,
select an entry in the browser, with a
symbol that you like mark the location in map window, select next, repeat...
If your table isn't yet mappable, you have to make it so and add it to your map window
before you start.
Enjoy.
=======================================================
I. If possible, I would scan and register the paper map and use it as reference. If
that's not possible, you can "eye ball" it with your existing vector files/tables.
The manual geocoding process is relatively easy:
1. Open your reference vector files/tables (or registered scan).
2. Open your tabular information in a browser.
3. Make your tabular info table "editable".
4. Cascade your map and browser windows (so you can see and use both of them).
5. Select a single record in your tabular info table.
6. Click on the TITLE BAR of the map window to make it the active window.
7. Select the "symbol" tool and click the correct location in the map window.
That record is now geocoded. Repeat the process 170 times.
Another thought is to place all 171 points in a new table with a unique id attribute
that matches a unique id attribute in your tabular info table. Then combine the two
table with a SQL a join.
Good Luck.
====================================
Laith Wark
EDAW (Aust) P/L
Design, Planning and
Environments Worldwide
Level 4 Rowes Building
235 Edward Street
Brisbane 4000
Australia
Ph: INT +61 (0)7 3229 6422
Fx: INT +61 (0)7 3229 6422
Email: [EMAIL PROTECTED]
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