Tropical Cyclone Winds at Landfall:

The ASOS Wind Exposure Documentation Project

Documentation Instructions - Guidelines

(Please check for recent updates to these instructions and for the answers to frequently asked questions FAQ)

During routine maintenance visits, photographically document the upstream wind fetch exposure of ASOS stations in areas potentially affected by landfalling hurricanes. A list of WFO's in this category are listed in the FAQ and cover from Texas to Maine, Hawaii, Guam, Puerto Rico, and the U.S. Virgin Islands.

Tools needed:
Nikon Cool Pix 300 Digital camera (640x480 resolution)
2 sets of fresh 4 AA sized batteries
A compass (with bearing sight if available)
A GPS unit
A measuring tape
Tools for lowering the anemometer mast
A notebook.
A range finder (if available) could help estimate distances to major obstacles.

Before Starting

Be sure you feel comfortable with the operation of the camera and especially with how to use the text annotation and voice recording features, how to download the images on to your PC using Nikon View software, and how to enhance the images to improve their quality using the Photo Enhancer software.

Make sure you have plenty of memory to store the needed images (8), text files (8), and voice files (2). Delete files that you no longer need. Setup the camera for "Single frame" shooting mode, Speed-Light Flash to "Off", Image quality to "FINE", Sound mode to "On" and "Mode 2", Speaker to "on" volume "3", Self timer to "off"

Check the manuals that came with the camera for more information. Its a good idea to take some practice images and download them to the PC before going into the field.

I. Documentation Procedure

1. Park your vehicle far enough away (50-60 yds) from the site that it will not significantly block the view of the upstream exposure. Use the handheld GPS unit to measure the latitude and longitude of the ASOS instrument bank in degrees, minutes, and seconds and write it in the notebook.

2. Determine the height of the anemometer mast using one of the following methods:

1. Measure the length of the colored bands. If the length is 51 in. you have a 33 ft. anemometer height . If the length is 39 in. then you have a 26 ft. anemometer height.

2. If the bottom change from orange to white is directly behind the wind electronics enclosure box, the anemometer height is 33 ft. If the color change is below the electronics enclosure, the anemometer height is 26 ft.

3. If the grounding lug (attached to the mast about 7 ft. above ground) is in the 2nd white band from the bottom, the anemometer height is 33 ft. If it is in the 2nd orange band the anemometer height is 26 ft.

4. If in doubt, lower the anemometer mast and determine the height of the anemometer with the tape measure and write it in the notebook. It may be helpful to have an electronics or ASOS technician to assist.

3. Use the voice recording button to record a short message, (If your browser can play ".wav" files Click Here) with the Lat and Lon (in degrees, min, sec) Anemometer height.

4. Photos of exposure for 8 compass headings (every 45 degrees)

a. From a distance of about 30-40 yds. away from the mast, use the digital camera to document the upwind exposure. Keep the anemometer mast in the center of the image on the compass heading, in the middle to lower foreground of the image, but not so close that it obstructs the view . A sight on the compass will help to position the camera at the proper heading. Start at 000 or 360 (North) and then continue the exposure photos every 45 deg of compass heading. To help keep the images in order it may be helpful to record a brief voice message noting the compass heading, station ID and major obstructions to the flow (including their estimated distance and height). The wind exposure documentation will consist of 8 pictures per station, taken every 45 degrees of direction relative to true north centered on 0/360, 45, 90, 135, 180, 225, 270, and 315 degrees (Opalocka Airport Example). It helps to start with North 0/360, and then move clockwise to 045, 090, 135, 180, 225, 270, 315. Having the mast in the center foreground helps to aim the camera on the correct compass heading. Taking the photo from 30-40 yds away allows for some overlap on adjacent images giving a broader view of the terrain upstream of the mast. Keep the camera LCD covered to help save battery power.

b. Once the 8 pictures are taken, return to the vehicle and use the text annotation feature of the camera to add the direction the camera was pointed in and the 3 letter station ID.

It is difficult to see the image on the LCD screen outside even on cloudy days. The shade inside the vehicle will help the LCD display to be viewed more easily.To add the text, go to the menu and select the first picture you took, then use the stylus pen and touch the image lightly (three color blocks will show on the screen), lightly touch the red block and then write the station ID and compass heading on the image, then hit the return button with the pen and the text will be saved along with the image. Try to write small, clear and legible on the sky or cloud background without blocking the ASOS sensors or upstream terrain features in the image. Then use the arrow to advance to the next image and annotate it.

Repeat this for each of the eight compass directions: 0/360, 45, 90, 135, 180, 225, 270, and 315 degrees. Use the compass to identify significant terrain features or obstacles (e.g. buildings, trees) and document their distance and estimated height in the notebook. If available, use the range finder to estimate distances to obstacles.

c. After taking all 8 pictures and annotating them, Use your notes and the voice recording button to record a single concise message , (If your browser can play ".wav" files Click Here) pointing out major obstacles to the flow (the approximate distance, height and their heading from the anemometer mast).

5. Thats it for the field work! When field work is completed you should have:
(1) voice file with anemometer height and station Lat and Lon in Deg, min, sec.
(8) upstream exposure images
(8) text annotations associated with each image
(1) voice file summarizing major flow obstructions in each of the 8 direction sectors.
Notebook entries for Station ID, Date, time, personnel, Lat, Lon, anemometer height, and significant flow obstructions (with approx. distance and height) in each of the 8 direction sectors. Note ASOS documentation at your office may have some of the needed obstruction to flow information. Please also note whether emergency power (Uninteruptible Power Supply) is available for this station and the approximate amount of battery backup power time available.

II. Downloading Images and Sending information to NCDC

6. When you get back to the office, make sure that you have lots of battery power left in the camera or connect the camera to the A/C adapter, connect the camera serial cable to the serial port of your PC, turn the camera on, and download the images into a directory for the station ID. To download each image with the text superposed, start up Nikon View, select the camera, select an image file in the browser and click on the "Acquire" button. The image will be loaded into a window with the text file superposed. Then save the image as a SIDDIR.jpg file to a directory named after the station ID, for example all the files for the Opalocka ASOS will be in a directory named OPF and each file name will be Station ID (SID) Compass Direction (DIR).jpg e.g. OPF000.jpg for the image pointed due North. Be sure to save from the image window and NOT from the file browser. This will store the text and image as one file. Repeat until all 9 images with text are on the PC directory. Download the 2 voice files (e.g. OPF1.wav) from the camera to the same directory. It takes about 1 min to download each image or sound file from the camera.

7. If needed, use the supplied Photo Enhancer software to inspect the images and enhance them to improve their quality. Usually this involves changing the image to lighten it up on dark days or darken and sharpen it on very bright days. Check over all the images and text annotations to make sure things are legible and then put the final images in a seperate directory.

8. Using the notes taken in your field notebook,run the JAVA program supplied by HRD to fill out the form for the station Screen Grab and bundle the images and text annotation using the final directory location. The JAVA program will compress and archive the images and use the file transfer protocall (ftp) to send all the information for a particular station to NCDC. To download a copy of the JAVA program click here. This program will run on any PC, workstation, or MAC with a working Java Runtime Enviroment running java ver 1.1 or higher (Get Java JRE). Please check with your Electronic Systems Analyst (ESA) to make sure you have the JAVA runtime environment and a compression program (PKZip or WINZip) on your machine. If you have any problemswith the JAVA program contact HRD at Dr. Mark Powell.

9. If you run into problems with the JAVA approach,

Send the site info directly to NCDC by using anonymous ftp.

NCDC's ftp site address is:
user: anonymous
password: <e-mail address>
change directory: cd /pub/upload/
After ftp'ing the data, send an email to dave bowman:
The email should tell Dave that the file has been ftp'd, what the filename is, and what compression routine was used (tar, winzip, pkzip204g,etc.). If the JAVA app. was used the compression routine should be "zip". The email is critical so NCDC knows when to access the ftp serverbecause there is a time limit on the order of a week after which the fileswill be deleted from the ftp server. NCDC plans to access the server shortlyafter receiving the email so that if there is a problem, they can workto correct it while its fresh in your mind.

Frequently asked Questions
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All HTML designed and created by Nicholas Carrasco at the Hurricane Research Division(HRD) of the Atlantic Oceanographic Meteorological Laboratory(AOML) in Miami, Florida. Part of the Environmental Research Laboratories of the National Oceanic and Atmospheric Administration (NOAA), a part of the US Department of Commerce (DOC).