The topography tag has no wiki summary.
9
votes
3answers
418 views
What are common methods for converting raster digital elevation data to vector contours?
In researching this I have found many references to the opposite, creating elevation data from contours, but nothing regarding contour creation. Preferably, I am looking for open source solutions like ...
8
votes
4answers
1k views
How to aquire a topographical map of Britain?
First of all, let me say that I know next to nothing about GISs.
I'm trying to find / make / aquire a topographical map of britain. I want to use it as a height map in Dwarf Fortress so it needs to ...
7
votes
1answer
141 views
What does this style of line on Topographic maps indicate
If I was reading the purpose of this stackexchange site right, I could also ask general map questions. Not necessarily regarding software.
Anyways, I was wondering if someone could inform me what ...
5
votes
1answer
1k views
Calculate Topographic wetness index in SAGA
i am currently working on a project which involves the quantification of the wetness in certain areas. However it produces quite different results from what i expected. I'll describe the steps i have ...
4
votes
1answer
508 views
Terraserver replacment - source for US Topo maps?
Now that Terraserver has been shut down (or at least that's how it appears), is there an alternative WMS server for US topo maps? Probably too much to hope to find one that provides vector layers ...
4
votes
1answer
187 views
How to restrict or block certain paths in NetworkX graphs?
I am trying to calculate shortest path between 2 points using Dijkstra and A Star algorithms (in a directed NetworkX graph).
At the moment it works fine and I can see the calculated path but I would ...
4
votes
1answer
211 views
USGS Topographic Map Online API
I am creating a website for a non-profit organization and would like to plot points on a map similar to this: http://www.arcgis.com/home/item.html?id=931d892ac7a843d7ba29d085e0433465
I am currently ...
4
votes
3answers
461 views
Australian Topo Map GeoTIFFs
Does anyone know if Australian topo map GeoTIFFs are made available anywhere (preferably for free)?
LINZ makes them available in New Zealand - http://www.linz.govt.nz/topography/topo-maps/index.aspx ...
3
votes
4answers
868 views
Add UTM labels to grid in qgis
I try to use qgis to create a custom topographic map for outdoor use: UTM, 1:50000.
What these maps usually have is a 1km x 1km grid, which at the bottom is labeled with a shorthand for the ...
3
votes
1answer
50 views
What function should I use to assess the degree of elevational change (rocky cliffs etc.) of a DEM?
I have a DEM of my research area and I want to assess how the topography/elevation changes. I am specifically looking to see what areas may be good suitable bat-roosting habitat so I am trying to ...
3
votes
1answer
376 views
Map Grid Index / Reference for Canadian Topo Map
Does anyone know where I can find some kml at different resolutions to show the grid reference for the Canadian topographic maps (CanTopo and toporama). Much like is displayed on the map here: ...
3
votes
0answers
27 views
Library for parsing scientific PDS files?
Does a library exist for parsing the PDS files that scientific planetary data gets shipped as?
For example, here's a link to to the lunar topographic data from the Lunar Reconnaisance spacecraft ...
2
votes
1answer
88 views
I want to create my own topographic map
I need to create topographic maps for scales between 1:100,000 and 1:500,000. This is due to the fact that the official topographic maps in my country are offered in 5k, 10k, 25k, 50k, 100k and 500k. ...
2
votes
1answer
36 views
European Mountains Shapefile Data Sources
I am trying to locate a GIS freely downloadable shapefile (preferably polygon) of European main mountain chains (not an elevation data), eg Alps, Carpathian Mountains. I tried variuos sources , ...
2
votes
2answers
89 views
A library/software to create DEM from a topographic map
In one of my projects I need to digitize video clips showing some natural landscape. Specifically I need to know distances between different areas and elevation levels.
I have a topographic map of ...
1
vote
1answer
152 views
ArcGIS Online Topo Maps
ArcView 10.1 does not have this kind of topo map to "Add Data". Where do I find this type of topo map, preferably free. ArcGIS online does not seem to offer this type of topo, unless I am not seeing ...
1
vote
2answers
62 views
viewshed analysis for observers wearing visors?
I'm starting with a DEM, and looking to identify every point that can be directly "seen" from any point in a particular polygon on an overlaid layer defining an area on that DEM - like any other ...
1
vote
1answer
182 views
What are Bands, Dimensions, and Histograms in QGIS?
First; I can see a band as synonymous with a channel in an image editing program like GIMP, is this correct?
If so then bands play the role of color mixing and masking. Are there any other ...
0
votes
1answer
187 views
Plotting Smith and Sandwell global seafloor topography grids
Does anybody have any experience with plotting Smith & Sandwell 2-minute Mercator-projected grids in ArcGIS? I've downloaded one in two formats: ers and img. I've found tools for processing .img ...
0
votes
1answer
282 views
Calculate CTI TWI using raster calculator: Negative values
I am calculating Topographic Wetness Index for a study area using SRTM DEM (90 and 30m).
I understand there are many "flavors" of TWI (CTI).
I have been using: TWI = ln(As +1 / tanB)
where As ...
0
votes
0answers
24 views
How can I calculate raster cell area for upslope contributing area
I am new to spatial analysis, and urgently trying to follow this tutorial to generate a topographic wetness index for my area of interest:
...
