DATE:
June 25, 2012
TO:
Prospective Respondents
FROM:
Judy A. Bowen, CPPO, CPPB, Senior Contracts Administrator
SUBJECT:
Addendum #2 to Request for Proposals (RFP) #27377, Estimation of Rainfall Accumulations Using
National Weather Service Weather Surveillance Radar 1988 Doppler Data
In response to inquiries to the referenced RFP, the following questions and responses are provided for clarification.
Please refer to this information as you prepare your Responses.
Question 1:
In developing the evaluation dataset, does the respondent need to develop the adjusted radarrainfall data starting from raw reflectivity data, or should the respondent use the radar-rainfall data
provided on the ftp site for the four areas and then apply the gauge adjustment?
Response 1:
The respondent should develop an adjusted radar-rainfall estimate from raw reflectivity data.
Question 2:
It is not clear what information is included in the radar data posted on the ftp site for the four
areas. Do these data represent radar-rainfall rates?
Response 2:
The radar rainfall data provided on the ftp site for the four sample areas is representative of the
current District product and is provided for comparative purposes. The radar rainfall data provided
are rainfall totals for the respective periods expressed in inches. It is not a rainfall rate.
Question 3:
In delivering the evaluation files, should the respondent include all areas in each single monthly
file?
Response 3:
The respondent may include all areas in a single file, or in four separate files, whatever is most
convenient.
Question 4:
Provide more details on Qualification 11(d): Documentation on map registration for all steps of
data processing.
Response 4:
The documentation on map registration should describe the process used to transform the raw radar
reflectivity from spherical geographic coordinates into the planar coordinates used for the pixel
grid.
Provide more details on Qualification 11(e): Documentation regarding normalization procedures
between different WSR-88D radar unit outputs.
Question 5:
Response 5:
The documentation on normalization between different WSR-88D radar units should describe the
process used to mosaic the various radars together into a single data set and account for adjusting
for any observed differences between the individual radar calibrations.
Question 6:
Does Qualification 11(f) ask for the algorithm that respondent has used in developing the
evaluation dataset, or the algorithm that will be used if the respondent is awarded the contract?
Response 6:
The District expects the algorithms used to process reflectivity data into gauge-adjusted radar
rainfall estimates for the evaluation data set to be the same algorithms to be used if the respondent
is awarded contract.
Question 7:
The ftp site includes 15-min radar data for areas 2, 3 and 4, but does not include similar data for
area 1. Only hourly data is provided for Area 1.
Response 7:
Sample area 1 has only hourly radar data available (which has been provided on the ftp site). The
other sample areas have 15-minute radar data (which has been provided).
Question 8:
Can you explain more what is meant by "differential"?
Response 8:
The grid differential is the difference between one grid and another grid.
Question 9:
It seems that the District already has a radar-rainfall system that is running in real-time
(http://webapub.sjrwmd.com/agws10/radrain/) with an algorithm for radar-rainfall estimation and
adjustment. What is the intent of the new RFP in regards to the existing system/algorithm? Are
there any expectations from the new algorithm (resulting from the current RFP) in comparison to
the existing one? Does the District prefer to have a system that is similar to the existing one but
with future data?
Response 9:
The intent of the RFP is to find the best and most cost effective system to meet the needs for
gauge-adjusted radar rainfall estimates.
Question 10:
In the new algorithm, does the District expect the respondent to use Level II or Level III
reflectivity data?
Response 10:
Any new system/algorithm would be expected to be as good as or better than the existing system.
The respondent may decide to use level II or Level III reflectivity data, whatever product works
best with the constraints of their particular system/algorithm.
The time and date for the Proposal Opening remains at 2:00 p.m. on Monday, July 2, 2012.
Please acknowledge receipt of this Addendum on the PROPOSAL FORM provided in the proposal package.
If you have any questions, please contact me at (386) 329-4237, or fax (386) 329-4508 or e-mail
[email protected].