This FAQ is a collection of bug reports and questions received by email or phone, mostly from technicians out in the field. The email with answers are not beeing edited, nor are they translated when in Norwegian.

External instrumens (GPS, Echosounder, ARPA radar, gyro, autopilot, sattelite compass)

Seafloor mapping and depth data operations

Data storage

Chart plotter operations

Vector charts

ES60 and seafloor hardness measurements

Trawl positioning

Software download and installation

External instruments (GPS, Echosounder, ARPA radar, gyro, autopilot, sattelite compass)

Q:Can you please provide details of how to interconnect Wassp and Olex systems as we have to perform this interface on our customers new vessel

A:First, make sure the Wassp is configured so that its vessel reference point is the CG of the boat, or the point where the boat has the least vertical motion when rolling and pitching.

Let's say the vessel use an Furuno SC-30 or SC-50. This means you should also install the Maretron SSC200 close to the vessel reference point. The Maretron need to be programmed through Hyperterminal or similar for 38400 Baud and with all NMEA sentences disabled except for the $PMAROUT, which should have as fast as possible output rate, which I think is 40 Hz. Connect the Maretron to a serial port on the Wassp.

On the Furuno, activate the PFEC,GPatt and PFEC,GPhve sentences with highest possible output rate, and GGA and RMC at 1 Hz. All other sentences should be disabled. If RMC is not available (like on our SC-60), ZDA and VTG should be activated. All sentences needs to carry NMEA checksums.

Make sure the Wassp checks for NMEA checksums on all its ports. This is done on the Network dialog window in the Wassp GUI. The same dialog also lets you see the NMEA sentences; you should see both the Furuno and Maretron data.

The Olex should have an IP address compatible with the Wassp. We use since the Wassp has The unit you received from us should already be setup this way.

When powering everything up, the Olex should show a red or green blob in its Multibeam window on the lower center section of the screen. A gray blob means there is no connection with the Wassp, ie wrong IP address, cabling error, or such. Any non-green blob will be explained by error messages on the Multibeam -> More dialog. "No pinging" or "Too few bottom points" are not too bad, usually caused by no bottom detection on the Wassp. Other messages may detail missing pieces of information, like no attitude if the Furuno or Maretron is powered off.

On the Multibeam -> More button, you should see the motion sensor being detected as Furuno+Maretron. Configure the position of the heave sensor related to the same reference point as used by the Wassp. For a boat with the SC-30 it should be the same as the GPS as configured on the Wassp, while for the SC-50 it should be a different point, namely the spot where the electronics box is installed. Olex use this information to correct the heave values in relation to both static and dynamic pitch and roll.

Configure your GPS lag on both the Settings menu and Multibeam -> More. This value is probably 1.0 seconds for the SC-30 and 1.2 for the SC-50.

The pitch and roll offsets will differ between Wassp and Olex, since the latter regards the difference between the transducer and the Maretron. The Maretron's roll and pitch zero points will be stable but not necessarily aligned with its casing, so one cannot trust offsets calculated by measuring different mounting angles. Seatrials needs to be done to fully decide these offsets. We use a 270 degree pattern to work out roll offsets, while pitch may be discovered by moving up and down slopes. Other forms of patch tests may also be used.

When you have a nice succession of green blobs, its time to go to sea!

Q: Please could you tell me the current list of supported multibeam echosounders?

A: Olex supports WASSP multibeam sonar and mosts Kongsberg EM multibeam echosounders. Models tested and found working are the EM120, EM300, EM1002, EM3000, EM3002, EM3002D and EM710.

Q: Since many time I'm thinking on how Olex manage the heading info. As you well know course (GPS) could be different than heading (Gyro), but Olex only shows the course information. Could it be shown the heading info in any way? Does Olex internally use the heading info for Arpa and ITI calculation?

A: Olex handles course and heading as separate values. You will notice that the ship symbol rotates according to heading (if available), while the movement vector is along the GPS course. There are also two different course and heading vectors shown. Course and heading is correctly handled internally for position calculation of own echosounder etc. Generally speaking, if heading is not available, course is used instead. Arpa and ITI is usually expressed as relative north, in which case heading is not really necessary for Olex

Q: According to your manual: "To ensure optimal quality of the seafloor map, the ship geometry and sensor placements must be correctly configured on the setting menu.Furthermore, for accurate measurements at low speed, gyro input is imperative." We are installing one of your units on a fishing vessel of ours.At this time we do not plan to interface the plotter with the gyro. It will be interfaced with GPS. Question: What is considered "low speed" at which accurate measurements will be unavailable? Drifting? Bare steerage? 2 kts?& 5 kts?

A: "Low speed" means speed so low that the GPS is not able to calculate the ships heading.Typically this is at 1 knot or below. The resulting degradation in survey quality depends on the lateral distance from the GPS antenna to the echosounder transducer. For a typical fishing vessel, this might not be something to worry about. For a 150 feet sand grabbing vessel, staying still in water, with the GPS at one end of the ship and the transducer at the other end, this might introduce a noticeable error, as the transducer appears to rotate around the boat due to random headings from the GPS.

Q: Can we send all the information to the PC on one data port? We will use a data multiplexer that combines all sentences input through several ports and combines this to send out one port. This will then be connected to the PC. We will be supplying Depth and Hardness from Simrad ES-60, GPS, ARPA targets from Radar and Heading from Gyro if possible.

A: In theory, all data could be sent over a single port. However, due to bandwith issues I advice against it. The combined throughput of GPS, gyro and radar might exceed the capacity of a standard 4800 baud NMEA line.

Q: Is there a data output for Autopilot?

A: Yes; when Autonav is enabled, Olex emits both RMB and APB on all serial ports.You could wire the autopilot on the same serial port that receives the radar or GPS.

Q: Finnes det noen kurs/fart filtrering av GPS-data i Olex programvaren?

A: Hvis Olex mottar RMC eller VTG fra GPS skjer det ingen filtrering. Hvis GPS ikke gir ut RMC, vil Olex selv beregne kurs og fart, kun utfra posisjoner, med 30 sekunders midling. I tillegg kan man sette Olex til å ekstrapolere kurs og fart framover i tid, for å "fylle inn" mellom posisjonsfixene. Dette er aktuelt for hurtiggående båter, og aktiverers på Diverse-menyen.

Q: Klokken i Olex er ikke riktig, selv om GPS er slått på.

A: Sjekk med Datatrafikk om Olex mottar RMC fra GPS. Hvis RMC viser feil tid, må RMC slåes av på GPS.

Q: I have some problems to collect the depth information from an Atlas Eco sounder. I receive in the Terminal window the sentence : $PKDBT,,f,0004.9,M,,F,*37. After testing with a communication program, it seems Olex doesn't accept the checksum (*37) at the end of the depth sentence.

A: The sounder is brain damaged and miscalculates the checksum; Olex correctly ignores the erroneous telegram. There is already a secret and slightly dangerous fix for this problem. Just make sure that the file "utensjekksum" exists in /home/olex; then the system silently turns off all checksum controls. For example, stop the system with ctrl+shift+right mouse button; type "touch utensjekksum"; type "reboot".

Q: Under installasjon viser ikke Olex den kurs og fart som GPS viser - f.eks GPS viser en tilfeldig skiftende kurs, mens Olex viser rett nord hele tiden.

A: Det er først når farten overgår 0.5 knop at Olex anvender kurs og hastighet gitt av GPS. Dette for å unngå at båten roterer tilfeldig rundt mens skipet ligger i havn.

Q: Under Diversemenyenen viser plutselig "Offset fra UTC" en crazy verdi (f.eks 32976).

A: Dette er en bug som er reparert i Olex 3.4. Dette kan opptre hvis Olex må synkronisere datamaskinklokken med GPS-klokken. For øyeblikkelig hjelp gjøres følgende: Få fram terminalvindu med Ctrl-shift-høyre musetast, Utfør kommandoene: rm lokaltidtabell reboot

Q: Please could you advise how to disable a port from listening to certain NMEA sentences?

A: On Olex version 8.2 and higher: "Layers -> Show data flow", click on any sentences you would like to disable.

Seafloor mapping and depth data operations

Q: Do Olex demand the differential GPS to calculate the depths?

A: In version 2.27 and newer, there is no longer need for dGPS.

Q: Will the C Map charts give us a starting point for 3D information?

A: The C-Map charts are NOT used for initial dephts; the quality is by far not good enough.

Q: Jeg skulle gjerne tatt de tredimensjonale kartene ut i windows og over i for eksempel word-filer for dokumentasjon. Er windows "klipp og lim" mulig med olex ? kan vi snu og vende på de ulike 3-D plottene slik at de blir mest mulig tilgjengelig visuelt ?

A: Maskinens 2D- og 3D-bilder kan skaleres og roteres før de taes ut på printer eller  til TIFF-filer på diskett. Det burde ikke være vanskelig å bruke skjermbildene i word-dokumenter.

Q: Dybden på skjermen viser 3 m, tidevannskorrigert bunnkart viser 2m, men det er ca 8 m dypt der båten ligger. Ekkoloddet er et Simrad ES60 ekkolodd

A: Draft på ekkoloddet er ikke satt.

Q: We have an Olex with strange data. In 3D it comes with spikes from the bottom up to the surface, but ín 2D it shows no depth when you go over it with the pointer.

A: We have recently discovered this bug, appearing when the depth is exactly 1000 m. Olex then gives the value 0 m. The bug is fixed in Olex 3.8

Q: Må ekkoloddet gi Olex dybden i meter?

A: Nei, Olex kan motta dybden både som meter, fot og favn, og dette er helt uavhengig av om Olex selv viser dybder som  meter, fot eller favn.

Q: En del av de kalkulerte dybdene forsvinner når man zoomer ut. Når man zoomer inn kommer dybdene tilbake.

A: Maskinen kan ha gått full på harddisken, blitt slått rått av under kalkulering, eller ha defekt harddisk. Det siste kan sjekkes ved å lete etter feilmeldinger i /var/log/messages.

Q: Depending on scale, rectangular parts of the seafloor maps are missing.

A: This is due to some depth files missing. Scenarios: The disk runs full when calculating, so not enough room. Not likely if Olex is installed on a reasonably big disk. More probable, the system was shut down abruptly during recalculation - although this should not erase too much. Large scale data loss is typically due to faulty hardware. Browse through /var/log/messages*, and look for hard disk errors; symptons like "bad blocks", "ide bus reset" and the like. To recover, export all the data to diskettes, rm -rf Dybder, mkdir Dybder, reboot, reinstall from diskettes.

Q: Because the echo-sounder collected depth between surface and fish (and not seafloor), we have a collection of bad bathy cells. How to erase these bad cells without erasing the other good bathy cells belonging to the same track ? It will be great to select a geographical rectangular area and have some tool to erase selectively bath cells (between 2 depths for example) or some types of marks.

A: There are already provisions for erasing single and multiple depth boxes, all falling inside definable depth ranges, and all following a certain trip.

Q: In some areas you have some measured depth cells but not any bathy calculation around the cells, and sometimes some measured depth cells on orange area. Sometimes it's the contrary : no measured depth cells but blue color display at the sea level (close to orange areas)

A: This happens when the system is stopped before finished with some depth imports. Recovery as in previous answer, or if you are lucky, just reimport the data.

Q: It seems that every time the depth is more than 1000m, Olex records crazy values (4263m, 5044m ... instead of 1200 meters for example)

A: I have just discovered a bug introduced around 2.27, which generates garbage depth data for depths greater than 1000 meters. The symptom is that the depth of calculated areas varies when zooming through the different levels, and that the real depth boxes are around 1000 meters shallower than the innermost calculated boxes. This bug is fixed in the upcoming version 3.2.

Q: If I load a lot of depth data in to the Olex then it starts calculating the new data and that may take 1-2 days. Is it safe to turn off the machine when it is calculating? Will it continue calculating when I turn it on the next time?

A: No, it is not safe to turn off the computer while calculating, then you will loose all the data.

Q: There have been questions coming from captains about the 3D picture. They say that it is not always good to see the difference between shallow and deeper water.So would it be possible to have more zoom or better color discrimination with more colors, or to have the 3D picture bigger?

A: The newest version (Olex 3.2) increases the possible 3D zoom range from 8x to 32x. Hope that helps somewhat.

Q: What happens if two measurements hit the exact same spot?

A: If one cell is measured many times, there will be calculated a veighted mean value of the measured depths.

Q: Can you tell me what reference points are used for the tide calculation around Iceland ?

A: The reference point are displayed in the file "harmonics", which contains all reference points world wide. Example:

/home/olex% grep Iceland harmonics

This will show all reference points for Iceland. If you want to add information, please follow the link to the Xtide people on our web page.

Data storage

Q: A few questions for you. Now I have gathered some new depth information to a single Dybder directory and I was wondering if I could compress it and save it to a windows partition and write it there to a CD and send to you. Or compress it and save it to an windows partition and send to you over the internet?

A: You can make a single file of the Dybder directory by the command:

/home/olex% tar czf dybder.tgz Dybder

This will make a file called dybder.tgz which is a so-called tar archive. This file can then be sent to us by email, burned to CD etc. You probably have setup your system for dual booting; moving the file to Windows can then be as easy as just

/home/olex% cp dybder.tgz /dosc

Q: Is it possible to uncompress the data on the diskettes we have and put them on a CD so we can be faster installing depth data?

A: The content of the diskette can not be uncompressed in another computer environment. But the files can be burned from the Olex computer using xcdroast. The procedure are as follows:

/home/olex% rm -rf diskett

/home/olex% frafloppy | tar xvf-

/home/olex% ls diskett

There should be three files in the diskett directory. One is called "dybder.gz", and this file must be burned on the CD.

Q: Is there any way to be quicker with the installation of depth data, that is install data from maybe CD or ZIP so the plotter would not have to recalculate everything? To save time.

A: If you just want to move complete depth datasets, you could store the Dybder directory to a zip or something... but usually, you want to add instead of replace data. The computer will only recalculate the differences, so two boat with lots of common data will not prompt a complete recalculation.

Q: We have a portable ZIP drive here in our workshop and I was wondering if it was easy to connect it and use to save depth data uncompressed? 

A: I run my zip 250mb on my laptops paralell port. But there are some configuration. You should read the pertinent documentation. To actually save files, use normal Unix commands like cp dybder.gz /mnt/zip.

Q: I had saved routes and marks on a diskette from one computer and went with the diskette to another computer and saved routes and marks on the same diskette, but then when I went to the third computer it seemed as all that I saved from the first computer was erased. Is this normal?

A: Yes, when you save something on a diskette, it erases all that was stored before. So, if you want to collect tracks from two boats and give to the third, you should first import #1's data to #2 before backing up #2 to #3.

Chart plotter operations

Q: A skipper has asked me for a problem he is seeing in Olex:When making a track of it own vessel everything goes OK until he makes a turn, in that moment the trak is not round but is made by segments, in a non soft way. I thought it was due to not having activeted the option continously updated ship position, but this was already activated. The GPS they are using is a Sercel dGPS receiver. What can it be due to?

A: The short explanation is that he has the chart zoomed in to much, below the probable GPS resolution.

The long explanation is that his straight track line is not really straight either. The GPS position is accurate to maybe 20 meters. This error is slowly moving around, so if he stays put and notices the position it might appear to be much more accurate; but if he samples it over some hours, he will make a circle with a radius of 15-20 meters. Olex knows this and stores new turnpoints along the track line only when the distance from measured to stored track exceeds 15 meters. This ensures that the system will not be filled up with millions of turnpoints as the boats measured position snakes around the straight actual track.

If the chart is operated in a scale above the GPS position noise, this sampling will not be visible. You could say that Olex is too lenient with the user, and lets him zoom in too much. Same goes for the vector charts; Olex lets the user zoom in so much that small islands looks like large and crude rectangular blocks. But, one could argue that the estetic smooth track curve is more important than the technical correct angular one you could also utilize a more expensive and accurate GPS. Therefore, in Olex 3.8, the threshold for track deviation when tracking the boat has been decreased from 15 to 5 meters.So, by upgrading his Olex he should enjoy smoother, but somewhat artifical, curves.

Q: How long does it take from a trip ends until a new trip starts when "New trips are started automaticcaly" is on?

A: The vessel have to lay still for at least 15 minutter.

Q: Hva er tanken med skipssymbolene på menyen Turer?

A: Dette er for manøvertester - med tilkoblet gyro kan man studere båtens manøveregenskaper.

Q: Slepestrekene forsvinner fra skjermen når de avsluttes. Er det en bug?

A: Sjekk at Slepestreker ikke er slått av under Infomenyen

Q: The boat is very far from the coast, and there is still the display of the tides from his original harbor. Meanwhile, the boat is closer to other harbors. What is the limit in distance from the harbor for the tides correction ?

A: The tide places are valid for 100 miles. Maybe his other nearer harbours is not included in the tide database?

Q: Olex vil ikke vise levende lykter

A: I kart av format NSKV vil Olex ikke kunne vise fram blink-karakteristikk til lyktene. Løsningen er å bytte til S57-kart eller kart fra C-MAP. Nordpå er det områder som kun er dekket av NSKV.

Q: Why don't I get latitude/ longitude when I'm using the Distance measurements in 3D ?

A: If you mean the option "Continuous ranging arrows", this is not active in 3D modus. Use a mark for the distance measurement instead.

Vector charts

Q: I have some lat/lon/depth data in Europa 50 (datum of the official French paper charts).So I guess that I need to convert them in WGS84 to match your system.Is it correct ?

A: C-Map charts should all be in WGS84; original ED50 charts are converted by the chart maker. The exception is some obscure charts where C-Map was not able to deduce the encoding datum. In the newest Olex version, if such a chart is displayed, a prominent warning is shown.The depth database is datumless; it assumes a spherical earth. This is OK since the radius of interpolation is short enough. It is correct that you should convert your ED50 data to WGS84 before letting Olex have a go at it. Futhermore, depths should be referenced to the lowest tidal water level.

Q: I am having some trouble concerning C-map charts. How does one install the charts? When I run the CD and try to install charts, I get the error message "Authorization required" or " Missing Authorization". According to Cmap, after installation one gets a authorization code to unlock the charts. The thing is , how do I install the charts to get this code?

A: Have you tried the inbuild C-Map chart catalogue in Olex? This is for ordering the charts. Use the catalogue to browse through the different zones, and just order the charts in question. When finishing the catalogue, a uniqe code will display, which must be sent to C-MAP (usually by phone) - who will return an "unlock" code for the ordered charts.

Q: Ved oppgradering fra versjon 2.16 til 3.0 forsvinner alle kartene i maskinen, både C-MAP og Sjøkartverket sine.

A: Maskinens harddisk har gått full under innlesing fra CD-platen, eller katalogen "kart" har ikke blitt lest inn korrekt. Gå "bak" kartet med <Ctrl-Shift-høyre musetast> . Sjekk plassen med kommandoen

/home/olex% du

Sjekk deretter om katalogen "kart" og filen "kartid" finnes i maskinen. Hvis disse mangler, f.eks katalogen "kart", kan denne leses inn på ny fra CD-platen med kommandoene

/home/olex% mount /mnt/cdrom (det kan hende man må være superuser for å utføre denne)

/home/olex%tar xvfz /mnt/cdrom/kart.tgz

Hvis man får feilmeldinger, kan CD-platen være skitten eller ødelagt.

Q: Can I install C-MAP charts while Olex is calculating?

A: Yes.

ES60 and seafloor hardness measurements

Q: I have a customer who has an EK500 and an EQ60 both with BI500 Telegram transmission. He also has the BI500 postprocessing software installed in a SUN workstation.I think BI500 telegrams can only be sent to a processing unit so he only can use the SUN workstation or the Olex software to lissten to the BI500. There are no problems when he use one echosounder for each BI500 processor, but what about if he wants to use only one echosounder and both processors at the same time? I think that two computers cannot use the same IP address (somebody at Horten suggested me that configuration). But in BI500 you can only configure one target.Do you have any suggestion to make it work easily?

A: I think that you can set the IP address in the BI500 dialog box as the recipient of the data... then all computers on the network will read the datagrams, regardless of their own addresses. The address is a broadcast of some sort. At least I saw a researcher do this on the ES60 onboard a research vessel, so that both the Olex and his BI50 unit got the datagrams. I am not an expert on TCP/IP networking, so you should try it before you take my words for it.

Q: We wish to buy a CM60 system so we can track the east coast, estuary and rivers. I would like to find out if the system will work in very shallow areas(1 meter) under the vessel ? Will I be able to use this data on GIS software back at the office ? I would also like to know if I can use a seabed classification system (RoxAnn unit) with the CM60 while it is running? Can I survey over inertial sand banks when the tide is in ? How will this CM60 show this on a 3D display? Do you use the tide references from the C-Map ? Do you use an external tide references ? Will I be able to put the draft of the vessel ? If so can I use this to help cross sand banks when the tide is flooding in or ebbing out ?

A: The CM60 uses XTide2 to reduce all depths to low low tide. Depths measured above the low tide level would thus not be shown, as negative depths are not handled. The tidal correction can however be turned off; manual tide input would then be necessary (possible, but cumbersome), by fiddling with the draft setting.Wether the system works in water less than 1 meter deep also depends on the echosounder in use. Depths are stored with 0.01 meter resolution down to 10 meter, 0.1 meter resolution from there to 1000 meter, and 1 meter resolution down to about 6000 meter. Lat/lon resolution is tunable, default gridded to 5.5 meters. No data from C-Map are used when surveying. Vector charts is not really necessary at all, but nice for navigation and orientation.There is an experimental and untested interface to RoxAnn and SeaScan included. Draft and antenna/transducer offsets can and should be set. Fairly raw data can be logged to ASCII files, consisting of lines with time, position, depth, tide level and backscatter.

Q: A CM-60 connected to Simrad ES60 WITH ES38B transducer using version 58 software, CM 60 software version 4.1 shows depth with blinking yellow light. Depth is 37 Fathoms. Pulse length on ES-60 is set to minimum of .256 msec. What is wrong?

A: The 38B is a very narrow beam transducer, so I think you would need some 60-70 fathoms of water for correct hardness measurements. You should upgrade to Olex 4.11, which allows too-shallow hardness as an excemption to the rules It will also give nice and verbose error messages explaining any yellow or red blinks; maybe your installation is too noisy or somesuch, and that would be evident with this new version.

Trawl positioning

Q: Is it possible to track the trawl with the ITI system without the Olex ITI option?

A: No, that is not possible. For connection to Simrad ITI, the system needs the additional software package HPR/ITI.

Software download and installation

Q: What is the spec of your laptop running Olex? I am looking into selling pre-installed portable Olex systems that skippers can take with them from boat to boat.

A: The only requirement is that the laptop must be able to run Fedora. A good choice would be one based on the Celeron-M or Pentium-M, Intel motherboard like the i915 or i945, onboard graphics, 256Mb RAM or more, 40Gb disk or more, builtin CD or DVD reader. A screen resolution of 1024x768 makes it easier to interface to external displays. There is no need for any fancy graphics since Olex constructs the 3D images by itself; no graphics card magic is involved. Beware of laptops with ATI X1300 (or other high X-numbers) graphics. The ATI X300 is nice though. Also, SiS and VIA motherboards with their strange graphics are to avoid. The latter often comes on AMD-based computers, so avoiding AMD often means an easier life too. Basically, the cheapest laptop from Dell etc are often a very reasonable choice.

Q: What is the correct procedure for downloading the software? We want the navigation software with 3D and the hardness software. I only see demo versions on your Web site and no hardness option.

A: There is only one version of our software. Various parts, like ITI and ES60 with hardness, are unlocked through the software key, or the nokkel as we call it. It is this nokkel that we actually sell. However, when running in demo mode all options are available. So, if you download the current version from our ftp server, you get the whole package; to run onboard a ship you must obtain the correct nokkel.