Lemon Glacier Project

From Seamonster

Jump to: navigation, search



Contents

Introduction

One of the goals for this summer (2008) is to get a complete data set on and around Lemon Glacier. We would like to publish some of the results and possible use them to write up a proposal for Mendenhall glacier. (See Lemon Creek Glacier 2009 for information about measurements in 2009)

List of Sensors

  • GPS: Different Locations on Lemon Glacier NetRS
  • Temperature: Upper Lemon Glacier WX, Lower Lemon Creek WX, Lower Lemon Creek YSI
  • Humidity: Upper Lemon Glacier WX, Lower Lemon Creek WX
  • Precipitation: Upper Lemon Glacier WX, Lower Lemon Creek WX
  • Stage: Upper Lemon Lakes Pressure Transducer
  • Discharge: Lower Lemon Creek USGS Gauging Station

Communications

See 2008 Build for more detail on communications.

  • Cairn Peak <-> NSRL (or Matt's rooftop)
  • Cairn Peak <-> Upper Lemon Lakes
  • Cairn Peak <-> Upper Lemon Glacier WX
  • Cairn Peak <-> Heinzelmann Ridge <-> Lower Lemon Creek WX

Events to capture

These events dictate our time plan to get everything ready... The first event is anticipated around the middle of May and the instruments should be out by mid-April. The lake drained in mid-July last year.

  • "Spring awakening" of the glacier. When the snow melt starts to drain underneath the glacier instead of running off the surface.
  • Lake drainage.

Questions to answer

  • Which meteorological events trigger the lake drainage?
  • How is the movement of the glacier influenced by precipitation, snow melt and lake drainage?
  • Does the movement of the glacier propagate down the glacier like "waves"?
  • Can the annual motion of a glacier be related to general seasonal weather patterns, rather than local conditions?

Preparations

NetRS

See also NetRS page.
Goal: Get the NetRS data recovery figured out, and into the DB. Test out the NetRS on the roof: Move the NetRS and compare it with the data. Figure out the setup to install the NetRS on the glacier. Have it running on the rooftop with solar power for a while. Attach communications. Get them on Lemon Glacier.

Marijke 12:26, 7 May 2008 (PDT)
The post-processing of the data is fully automated now, detail can be found at Automating OPUS GPS Post-Processing.

Marijke 13:50, 2 May 2008 (PDT)
I tried out the cutting of the data files with teqc to get 15 min files from one daily file, which seems to work fine, but the automated sending to opus works only sometimes (the solution to this was to have the shell sleep a couple of seconds before sending out the next file to opus). This prompted me to finally sent an email to Timothy Bartholomaus to ask what length of data files they used (Response of glacier basal motion to transient water storage, here's the answer:

  • Timothy Bartholomaus: Thanks for your interest and I'm excited to hear about more work on the linkages between glacier hydrology and glacier dynamics (ref: Sarah Das' paper on greenland lake drainage in Science, and Robin Bell's review article on glacier hydrology and ice sheet Mass Balance in Nature Geosci, both out within the last couple weeks). These certainly are exciting times. We were using all Trimble hardware and software on the Kennicott Glacier project. As I recall, our receivers were recording positions somewhere in the every 3-15 sec range. Data files were then chopped into hr-long pieces and all positions were processed statically in Trimble Geomatics Office. UNAVCO was indispensable in providing guidance through these steps.

Marijke 11:46, 1 May 2008 (PDT)
Two NetRS stations are programed and ready to go on the glacier, including the structures for solar panel and antenna and the cases for the batteries. The NetRS that used to be online and accessible through http://gps.jun.alaska.edu has been changed to platform 30, here are the old internet settings: 

   IP: 137.229.208.20
   Gateway: 137.229.208.1
   Servers: 137.229.196.94, 137.229.253.183, 137.229.10.39
   Domain: Not Set
   Search Path: jun.alaska.edu

The new settings are: 

   Name: LEMa
   IP: 192.168.1.30
   Gateway: 192.168.1.1
   Servers: 192.168.1.1
   Latitude: 58.368656°
   Longitude: -134.346629°

and: 

   Name: LEMb
   IP: 192.168.1.31
   Gateway: 192.168.1.1
   Servers: 192.168.1.1
   Latitude: 58.386141°
   Longitude: -134.348545°

The two NetRS also have platform_id's 30 and 31 respectively. The data logging is set to collect one file per day, which minimizes the number of files and still leaves the option to cut and splice them afterwards. Both stations are set up on the roof for final testing before deployment. The upper station (resting on snow all summer long) will be anchored in the snow by two longer rods, attached to two corners of the structure (the same will be done to the battery enclosure). The lower station (snow will eventually melt away leaving the station resting on ice) will have shorter rods on each of the corners of the structure (same for the battery enclosure). These rods are meant to keep the unit from sliding away in the case that the snow melts away at an angle. The lower station will be checked on later in the summer to see if it might need more support to keep it from sliding, for example a pvc pipe that is drilled into the ice along which the whole structure could slide down with the ice melt.
Image:P5010004.jpg

Marijke 10:47, 28 April 2008 (PDT)
The NetRS on the roof seems to be happy on day three (2 days of rainy weather). To be able to download the data through ftp with the hand held vaio, I had to add the ftp service on the vaio and enable anonymous ftp on the NetRS (On the web interface go to 'Internet' -> 'FTP' and enable the anonymous ftp without deletion of files). I set this up on both of the vaios and both of the working NetRS.

Marijke 17:39, 25 April 2008 (PDT)
Nick finished both of the structures for the antennas and the solar panels. Now we just have to wait for the charge controllers to get here and then we should be ready to go. I set up one of the NetRS on the roof, but it was giving me trouble and is not starting up right anymore even when I bring it back inside and plug it into the wall power, in the same setup it was working this morning. I will try out the structure on the roof with a different NetRS.

Marijke 17:19, 15 April 2008 (PDT)
I tested the NetRS with and without pigtail, and it looks like the pigtail does not change the result too much (First try: about 6 cm difference, second try: about 2 cm difference). I'm running a couple more test runs (mainly 15 min data sets) to see what accuracy we can expect in our results.
Started to automate the interaction with the OPUS website ( Automating OPUS GPS Post-Processing).

Marijke 12:27, 9 April 2008 (PDT)
We are switching from Auto Gipsy to OPUS for the post processing.
To test if the 2.4 GHz pigtails work, I set up a 3 hour logging session on 137.229.208.20 and 192.168.1.134 where the first one is directly connected to the antenna and the second one is connected through a pigtail. We were having some issues with converting the data to rinex and will try some more tomorrow (I installed the trimble utilities on nsrl1, but I guess I didn't do it right since only part of it is working).

Marijke 11:49, 7 April 2008 (PDT)
NetRS on roof after 5 days: Battery 11.56 V, NetRS not running anymore. The manual says that it shuts off when the power is below 12 V.

Marijke 15:29, 2 April 2008 (PDT)

  • Jason Admundson: Details for their tetrahedral support structure; eye bolts to hold together the bottom 3 angle irons (eye bolts can be chosen longer to have a sort of spike in the ice to hold the structure in place). Where the top three angle irons come together one of the sides is cut of on each iron and then they are bent towards the middle so that they overlap each other in a horizontal plane. Then a bolt is put through all of irons and on top of that the antenna is mounted. They made each side 1 m long.
  • Nick: Since we don't have many tools available it would be easier to build a cube setup to attach the antenna and the solar panel. I asked Jason if there are any downsides to that, he said that it should work. Matt ordered 2 or 3 solar panels, these are 30 W panels that are very compact: 19 * 16.7 * 1.31 inches.

Yesterday Nick showed me how to build the connectors into the pelican case and I finished one of them, cut the foam to fit everything and programmed the session just like it would be on the glacier. This NetRS is now on the roof, just attached to two parallel wired deep cycle batteries. It will start logging at 0:00 and I will keep checking the voltage (starting value: 12.50 V) to see how long it lasts without solar power.

Marijke 16:30, 31 March 2008 (PDT)
The NetRS have the capability to log data from external instruments such as temperature or humidity. We discussed this in the meeting and for our purposes we will set up a Hobo underneath the antenna or someplace out of the sun to measure the temperature at the site.

  • Test on roof: I set up a session in BINEX format, measurements ever 5 sec, duration 30 min, enabled at 16.35.
    • 16.41: Shaking of the antenna
    • 16.45: Direction: West, Distance: 24 in
    • 16.47: Direction: East, Distance: 52 in (always measured from previous location)
    • 16.49/50: Direction: North, Distance 3.5 in
    • 16.51: Direction: North, Distance 93 in
    • 16.54: Back to original location

Marijke 14:43, 28 March 2008 (PDT)

  • Roman Motyka: The tripod set up is used to measure vertical movement (uprise of glacier in ablation zone) and not necessary for our needs. We mainly want to see horizontal movement of the glacier. Roman suggested we should use a simple tetrahedron made of angle iron, which will anchor itself in the ice through melting. This setup will not measure long term vertical motion because of melt, but it might still pick up possible short spurts of vertical motion due to lake drainage or other hydrological events. Roman agreed that distances between the units of 1 - 3 km would be good for our purpose.

Auto Gipsy progress: Tried to run a test e-mail with the url given by unavco, but it didn't work. Wrote an e-mail and am waiting for an answer. The ftp directory seems to be all set up, now we just have to see if BINEX files work or if we have to use teqc to change it to RINEX.

Marijke 09:24, 27 March 2008 (PDT)

  • Martin Truffer: Roman Motyka knows about the GPS set-up, so does Jason Amundson at UAF. We use 1" EMT conduit (stainless steel) in 10' sections. The sections are put together with couplers made out of pipe by the GI machine shop. There might be some in Juneau (with Roman). We use three sets of poles and then put a plywood platform on these poles with a screw for the GPS antenna. The GPS, batteries and solar panel stay on the glacier surface and are attached to a fourth pole to prevent them from sliding away. We built a wooden frame work for solar panels with a large PVC pipe behind it that slides down the support pole. Jason might have some good pictures, mine are not very illustrative.

Ed installed teqc on the nsrl1 machine (137.229.208.19) today. This program can be used to convert BINEX into RINEX. I will start playing around with it today.
I'm starting to mess around with the Trimble NetRS itself, starting out by deleting all the sessions and data sets that are on there right now.

Marijke 18:28, 26 March 2008 (PDT)

  • Martin Truffer: 907-474-5359
Dr. Truffer recommended that we place the NetRS in a Pelican case and that we hook the two batteries up in parallel directly to the secondary power port. He noted that as the NetRS draws 3.5 W, 75-150 amp hr batteries will provide enough energy to last for a few days and that 15 W solar panels would likely not be enough to keep the batteries charged. He suggested using 30 W of solar. A charge controller is necessary when hooking the solar panels up to the batteries. When setting the unit up, make sure that the antenna is very well surveyed and that all the components are tied together. When placing the NetRS on a glacier, the Pelican case will inhibit melting under it, thus creating a pinnacle of ice down which the unit can slide. Sliding units/batteries pull on cables and mess up the whole system, thus it is necessary to place the unit on some type of stand that will keep it level and stable.
In regards to setting up the Net RS datalogging sessions, the following parameters should be used when working on the glacier or when setting up a basestation.Schedule: Daily logging starting at 0:00 and lasting 1439 min. Data Format: ‘.T00’ set to measure every 5 sec and determine position every 5 min. Leave the Phase smoothers set to default (unchecked).
Use the Data Transfer Utility from Trimble to convert files from ‘.T00’ to ‘.dat’, which can subsequently be brought into Trimble Geomatics Office (TGO) for processing (The licence for this software is very expensive, and so we are trying to get our data processed via Auto Gipsy, which means we need the data in RINEX. See Convert Binex to Rinex for NetRS for more info).

Requirements for "Auto Gipsy":

  • Anonymous ftp directory to exchange files with UNAVCO's auto gipsy.
  • The data has to be parted up in daily files.
  • File format has to be RINEX
  • The following naming convention is used 'ssssddd.yyt' where s = station name, d = day of year of first record, y = year, t = type of file (O = observation, N = Navigation, M = Meteorological data, G = Glonass Navigation file).

Progress:
The anonymous ftp is set up but it still needs some adjustments to the dreamhost panel because uploaded files cannot be accessed.
Possible ways of accessing the data on the NetRS at NSRL: 

  nc gps.jun.alaska.edu 5019 > outputfile

This will stream the output to 'outputfile' but it puts all the data into one single file. Port 5019 is set to give out the data in BINEX, which can be translated to RINEX through teqc. Another possibility is 

  wget -r ftp://gps.jun.alaska.edu --user netrsFTP --password 'pasword'

this will get all the single files that are on the NetRS and places them in a separate directory. Right now the file names suggest that each file contains one hour of data, the files seem to be stored as .T00 and .BNX (BINEX). The settings on the NetRS can probably be changed so that each file consists of one day.

Upper Lemon Glacier WX

Get Upper Lemon Glacier WX working on the rooftop for testing. Then installed on Cairn Peak again.

Marijke 17:54, 13 June 2008 (PDT)
Getting ready to have the data streaming through the uS. The Upper Lemon Glacier WX Campbell program was changed around so that it streams the last four entries of the table (15 min averages) every minute. This means the uS has to wake up at least once every hour to capture all the data from the previous hour. There were some problems with the CRBasics program, because it only allows a certain number of characters per line, so the year was cut off and is replaced again when the data is inserted into the DB. Right now the program is running on an empty CR1000 here in the office and the data seems to be running smoothly from Campbell to the DB, but the up down of the uS still needs to be changed around before it can all be deployed.

Marijke 14:43, 30 May 2008 (PDT)
Notes May 27th and May 29th.

Marijke 15:37, 6 May 2008 (PDT)
Logan and I set up the Cairn Peak Met station this morning. Details can be found in the calendar. A new charge controller will have to be brought up there, or we just leave it the way it is with the CR1000 connected straight to the battery.

Marijke 11:12, 29 April 2008 (PDT)
If we want to be able to turn off the uS to save power, we will have to figure out a different way of streaming the data. Right now it streams on each scan (every minute) and if the uS is not turned on, the data will be "lost". 15 min averages are stored on the data logger, and it should be possible to access this data and have scheduled downloads or something similar, it would be worth looking into the Pakbus utility of the data loggers, or see if it is possible to stream more data at once at certain times.

Marijke 15:57, 22 April 2008 (PDT)
The Upper Lemon WX is ready to be deployed. The humidity values seem to be a bit too low, but since it is our least important measurement, we will leave it like this for now and try to fix the old HMP50 probe to replace it later this summer.

Marijke 19:57, 21 April 2008 (PDT)
We didn't bring a tripod with us to Eaglecrest and were only able to reach the roof shortly with 3% signal strength. Here's a page to calculate the link budget. According to this, the most important parts of the link are the antenna types and the transmitter output power. It seems that with 28 mW output power from the router on the roof and an omni antenna, the connection was prone to be very bad. If we get a directional antenna at the router and a directional on Cairn Peak, we should be able to get a very good (18 dB margin) connection even with an output power as low as 28 mW. Some more actual tests are going to be necessary and we'll have to figure out a good tactic to aim the antennas. According to the specs the directional antenna has an 8 degree beam width, which means we should have a 2 km margin to hit the antenna on Matt's house from Cairn Peak. With two directionals this the margin to match up in the middle of the path is about 1 km, this seems to be doable, but we'll have to test it out in real life. Logan and I will try to get the van for tomorrow and and test it out some more in the wetlands.
The CR1000 is back on the roof and logging data. The internal battery still has 3.46 V (out of 3.6 V) so it should all be good to go. We bought 6 more batteries and tupperware for the batteries. Everything is ready for deployment (possible on Thursday 24th) for Upper Lemon WX, just the cable endings will have to be tidied up some.

Marijke 18:59, 18 April 2008 (PDT)
The data stream from the CR1000 - uS - router - DB on nsrl1 was working by the end of this day (Scripts can be found here). Changed the network settings on the uS and the router to 'infrastructure'. Just now I pulled down the uS and the CR1000 to get ready for the range test from Eaglecrest on Sunday. To use the uS and the handheld vaio for the antenna aiming, the ethernet cable from the bridge inside the uS can be plugged into the vaio, the ip address of the vaio has to be set manually to the same subnet, internet explorer can be opened and the web interface of the bridge can be accessed through 192.168.1.243. Click on 'Site Survey' to see the signal strength of all visible networks, this page updates frequently and the antenna can slowly be moved to achieve a higher signal.

Marijke 14:52, 15 April 2008 (PDT)
Got the chip replacement for the HMP50 (Temp/RH), replaced it but couldn't get it to work. Now I'm trying to use the HMP45C-L that used to be at Eaglecrest. Wrote a new CR1000 program that incorporates this new sensor (shortcut and then compared it with 'Upper_Lemon_050307', copied the parts for the CMP3 (Pyranometer) since it is not listed in shortcut).
Had some problems connecting to the CR10X in the office, sometimes it would work, but the connection was really flaky even though everything was set up in the usual manner. Not sure what the problem is. Everything seems to work fine with the CR1000 though.
I was fighting with the HMP45C program for a while, it was giving me clearly wrong values (-37 degrees Celcius, 0% Humidity). Turns out that the wiring diagram that shortcut gave was wrong, and after checking the wiring in the manual, it all works fine. Maybe that was the problem with the HMP50 too, I will play around with it some more (we really need some more "micro" connectors!).

Marijke 17:11, 9 April 2008 (PDT)
Tried to put together the same setup with the uS and the Campbell on the roof, but for some reason the communication doesn't work from the uS to my laptop in the office (this was working yesterday). When I connect directly to the uS (via ethernet cable and the vaio) it works and the data from the Campbell is streaming. The router is up and running too, and I can ssh into the router ('ssh root@192.168.1.1') then telnet into the brick and look at the streaming data that way. But I can't telnet directly from my laptop into the uS... I will have to talk to Ed some more about how the data should be transfered.

Marijke 10:47, 8 April 2008 (PDT)
The CR1000 only logged data until 17.45 because the power was too low (< 8.9 V) after that. Might be because the solar panel got covered with rime, I cleaned off the solar panel and got a second battery up there so we can try to get the data streaming with the microserver (uS).
Was able to telnet into the brick ('telnet 192.168.1.43') once in there changed to root ('su root') and looked at the data streaming every minute ('cat /dev/ttyUSB0'). The uS was removed to do some range testing, but everything worked really well. Now I need to figure out the details of getting the data into the DB over the uS.

Marijke 12:01, 7 April 2008 (PDT)
Got all the instruments together (including broken HMP50) and followed the wiring instructions on Lemon Glacier Cairn Peak Instrumentation from last summer. Getting everything on the roof now (11:00 AM), batteries and solar panel are already up there. Instruments are just resting on the roof, except from Young windmonitor. Put the wiring instructions into the field notebook.
To do:

  • Take care of cable endings
  • Designate 2 batteries
  • Buy tupper ware for batteries
  • Wires to parallel wire the batteries and power attachment for CR1000
  • Exchange chip in HMP50
  • Wire to ground the CR1000
  • Check if wind direction works

Marijke 18:28, 4 April 2008 (PDT)
Received the CR1000 program from Shannon and figured out how to get the data streaming. Shannon's program already has the instructions to stream the data, so I loaded it on the CR1000 (SN 8240). Set the time to AKDT. Data is streaming to putty. I changed the date format for the data streaming to fit the timestamp requirements of the database. Tested putty and normal download and both works fine.

Marijke 16:05, 24 March 2008 (PDT)
Instruments at NSRL:

  • 1 Temperature/RH probe (HMP50). Broken, a new chip (part number: 9598) was ordered from Campbell Scientific on 20070326.
  • 4 Tipping bucket Rain Gauge (TE-525L). One doesn't have a top, but the rest seem to be ok.
  • 1 Pyranometer (CMP3)(Solar radiation). Should be working.
  • 1 Wind Monitor (05103). Running on the rooftop of NSRL right now. Program needs to be checked, since the wind direction sensor was giving strange data last summer, but the sensor itself seems to be working.
  • 1 CR1000. Has a different program on it right now, so I need to find the program first and then I can test out the sensors to make sure everything is working.
  • The batteries were removed from the station, but the solar panel is still up there as well as the weather station tower. We need to make sure that all the nuts and bolts that are needed to attach the sensors to the tower are available.

Lower Lemon Creek WX

  • Get the Precip bucket back out to Lower Lemon Creek.

Marijke 13:51, 8 May 2008 (PDT)
The precipitation bucket was installed at Lower Lemon on May 6th. Data was downloaded and the station is still up and running just fine. During this summer it would be good to check on the station and download the date every 2-3 weeks.

Marijke 19:58, 21 April 2008 (PDT)
Tested one of the tipping buckets and labeled it to go to Lower Lemon WX. The YSI should be showing up and Eran and Josh will put it together and program it, so that it can be put in on the Thursday 24th flight.

Marijke 13:19, 7 April 2008 (PDT)
Put the wiring information into the field notebook. Just need to test a tipping bucket to make sure it works and get it out there.

Lower Lemon Creek YSI

  • Get the YSI back out to Lower Lemon Creek

Marijke 13:53, 8 May 2008 (PDT)
The new YSI was deployed on May 6th.

Pressure Transducer Lynn Lake

  • Get the pressure transducer to Upper Lemon Lakes

The pressure transducer was deployed in the lake on May 26th, more info can be found on the calendar. The program that was loaded on the CR1000 can be found in subversion. The wiring diagram is noted in the upper lemon field book and below is a picture of it.

Image:PDXWiring.jpg

On May 29th a solar panel was added at the site, pictures can be found on the gallery. And the field notes are here.

Retrieved from "http://robfatland.net/seamonster/index.php?title=Lemon_Glacier_Project"
Personal tools