POST
|
We just picked up a new Geneq RTK system and are using ArcPad 10 for our data acquisition. While using the system the position accuracy in ArcPad is displayed as 0.0 for both the horizontal and vertical. The elevation data is only displayed to one decimal place. Is there a way to change this? Working in meters I'm taking 0.0 error to mean that we have sub-decimeter accuracy, but it's important to know that for sure, as it is to know what the error is (is it +-2cm or +-9cm?). The RTK boats centimeter level precision and it's important to see that in the field. When I export the data back in the office it comes out to multiple decimal places in the X,Y, and Z. I'm wary of how much I can trust the decimal places when the error is only displayed to one decimal. Does anyone have any thoughts or experience with this? Thanks
... View more
01-07-2014
11:37 AM
|
0
|
2
|
3034
|
POST
|
I have thousands of storm observations downloaded from NOAA's web site as points (each point is an observation/measurement/location). When I try to convert those storms points to storm tracks using either the Points to Line tool in ArcMap or the ET Geowizards Points to Polyline tool, any storm track that crosses the 180 degree line ends up circling the wrong way around the world. I've attached an image. I imagine this is because when these tools connect the dots they move East to West by consecutive X/Y positions. When one point is on one side of the 180 degree line at say... 177 and the other is in the Western Hemisphere at -179, rather then taking the shortest path to connect the dots, the path goes to Longitude 176, 175, 173...2...0..-1...-100...-179. I've tried numerous methods to stop this. What worked for some of the points was to reproject the data using a UTM system, then calculate Lat and Lon in Meters, export the attribute table, and import that new table displaying X and Y using the newly calculated positions. But that only works for some of the data points (the points that fall within the UTM zone I selected). Is there either a global projection that does not use negative values at all, or is there a way to tell ArcMap to follow different rules when connecting the dots? It seems that even NOAA hasn't solved this. If you download the same data sets as polyline shapefiles (which they offer) no storms cross the 180 deegree line of longitude. There is an obvious gap in their data.... the same gap seen in my image. Perhaps some sort of routing is the answer? ***Update. It seems that if you right click on the Points to Line tool and select Properties, go to Parameters, then you do have the option to set a direction value. However these options are greyed out for me and I am unable to do anything but view the Parameters listed in the Pane.
... View more
01-01-2013
11:15 AM
|
0
|
1
|
1177
|
POST
|
What about this.... All I need are CSVs of the elevation along each transect that I have. I don't really care about the graphs. But since the graphs are elongated, exporting the CSVs from the profile graph gives me an unusable data table. Is there a way to convert my interpolated polyline shapefiles to CSVs that contain the Z values without messing about in the profile graph tool? Thanks.
... View more
12-08-2010
08:30 AM
|
0
|
0
|
368
|
POST
|
I suppose I could be thinking about this from the wrong direction. I'm interested in breaching points along the shore broken by my 100m sections. Instead of searching for barriers, I should be searching for the lowest continuous path north to south along each section. But since this is a shoreline, I can't start with one point and do a cost/distance analysis.
... View more
11-12-2010
04:44 AM
|
0
|
0
|
525
|
POST
|
What I have is Lidar coverage along a section of beach 76km long. I'm trying to show the probability of areas behind the beach flooding as sea levels rise. The Dunes are the barriers to flooding. I have several models that show various rates of sealevel rise over time. My goal is to show the probability of inundation along beach segments 100m wide. If I wanted to show a flood of the whole beach I would keep the Raster as one unit. But I'm interested in what areas have the greatest probability of flooding first. I figure that by breaking the beach up into my 100m study areas and then taking the maximum contour line that stretches all the way across that section I would then be able to say "here we see that sealevel would have to reach X meters before this portion floods. My model does not take into account the fact that once water breaches at one point, it will fill all the lower regions behind the beach, but it doesn't have to. I'm looking for the weak points. So being able to isolate the highest continuous elevation across a 100m section is key. I've played with converting my sections to polygons and then querying the polygons that intersect with specific contours, but that still does not give me only contours that run 100% across my 100m sections. So yeah... I have broken my swaths into 10m subsections and have removed all small contours with the intent of reducing error. But I figure there has to be a way to do this that doesn't involve fudging regions and accepting too many errors.
... View more
11-12-2010
04:10 AM
|
0
|
0
|
525
|
POST
|
Hi, I have a few posts relating to contours right now, dealing with some odd issues. I hope this is an easy question though. I am trying to create a contour table that I can use to auto-generate contours at certain intervals for numerous DEMs. I am interested in 0.1m steps from 0m to 3.3m. I created a text file to use with the contour by barriers tool, but it keeps generating errors or telling me that my contour.shapefile exceed 2gb in size. Yet when I do a general create contours at 0.1m intervals for the entire elevation range of my DEM, I get a contour just fine. I've attached my contour table below. If someone has any ideas where it isn't correct, I would like to know. The first 34 rows are the specified intervals, the last row should be the "from, to, by, indexed" information. Currently I'm getting a "Row 35 incorrect" error. Before I added Row 35, I was getting the file to big error. Thanks
... View more
11-11-2010
05:08 AM
|
0
|
0
|
1244
|
POST
|
Hi Dan, I have a couple of different posts going right now and missed your response. I'm not exactly clear on how this would work. I would have to generate contours from each of my DEMs, convert those contours to Rasters, but wouldn't this just tell me what the highest contour in each of my areas is? I need the highest contour that completely crosses my rasters. My rasters are 100m wide... I suppose I could look to find a way to select only contours that run 100m? No. Contours are irregularly shaped and a hill with a circumference of 100m should not be classed as a barrier for my purposes. Thanks for your advice, am I missing something here? I'm open to all ideas. Thanks, Richard http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//009z000000w7000000.htm for version 10 using the maximum option, however, every raster will be the zone and your contours will have to be grids if memory serves...a bit of a pain but check this out first and perhaps reformulate in light of this
... View more
11-11-2010
05:01 AM
|
0
|
0
|
525
|
POST
|
Hi, I have many rasters comprising a sizable study area. I would like to color code each raster by the value of the highest contour that runs through each raster. I'm doing some flood modeling and I have various water heights to try in order to flood each raster. The contours are the natural barriers. If flood waters rise 2meters, will this raster flood completely? If anyone has any thoughts on how to classify each tile by the highest contour that runs through it, I would be much obliged. -Thanks
... View more
11-09-2010
12:11 PM
|
0
|
8
|
2724
|
POST
|
Here's a thought... What about a conditional statement about contour lines that cross rasters? Can I set up a rule to assign one color to a raster if it is crossed by a contour line of a certain value? Example, if the raster is crossed by the 5m contour, it's red. If crossed by the 2.5, green. Now, how might I go about doing this for hundreds of rasters at once?
... View more
11-09-2010
09:40 AM
|
0
|
0
|
147
|
POST
|
Okay, so now I have hundreds of Rasters each comprising a stretch of beach (see my earlier post: http://forums.arcgis.com/threads/16896-Divide-a-raster-even-sections?p=53157&posted=1#post53157 ). I would like to assign each one color based on the highest elevation in each raster. Rather than go through by hand and classify based on value, is there a script or method to automate the process? For example, if the highest point in a raster is below 2 meters, I want it to be blue. If the highest point is above 9 meters, I want it to be yellow. So on and so forth... Any thoughts on how to do this? Can you reclassify a bulk set of rasters all at once? -Thanks
... View more
11-09-2010
09:05 AM
|
0
|
2
|
407
|
POST
|
Nope... never mind. Figured out the issue. The raster I was splitting actually had a 12 character File name (Location and Year). The tool wants to append a number at the end of the original Raster name to mark each segment. 0-9 made the filename 13 characters long. When I hit the 11th segment, the filename became 14 characters long and it all fell apart. It's scary how often the filename length is an issue. But once I made that realization, it all worked wonderfully.
... View more
11-09-2010
08:23 AM
|
0
|
0
|
600
|
POST
|
Hi Robert, I just started using Arc 10. Thanks for the advice. However, I'm having difficulties getting a usable output from the tool. The strip of land I would like to segment is ~77km long. I want tiles that run the length of the land North and South, but are only 100m East to West. I was unable to get the tool to work by specifying the size of the tiles. I did make some headway with number of tiles. I'll need about 770 tiles, but the tool only outputs 10 before it begins insisting that the other tiles already exist, "Failed to create 2004_10', it may already exist". The ten it does output are exactly what I need though... it's just 760 too few. Any thoughts? Thanks, Richard
... View more
11-09-2010
07:52 AM
|
0
|
0
|
600
|
POST
|
I have Lidar coverage over a large section of a beach. I would like to break that raster into separate sections 100m wide. I would then like to color code those sections based on whether a certain elevation exists in the swath. I can do this manually, extract by mask one section at a time, but is there a more automated way to do this? Say... by dividing a raster into multiple sections based on a polygon or something? Any ideas?
... View more
11-09-2010
06:15 AM
|
0
|
6
|
894
|
POST
|
Ever figure this out? I have a series of lines in a shapefile indicating where survey work was done, and I would like to get profiles of those lines from a DEM I have. There has to be a faster and more accurate way of getting the profiles than by redrawing each line by hand.
... View more
11-04-2010
09:00 AM
|
0
|
0
|
216
|
Online Status |
Offline
|
Date Last Visited |
11-11-2020
02:23 AM
|